The impact of a major hurricane on sediment geochemistry of a shallow subtropical estuary through strong resuspension

The impact of a major hurricane on sediment geochemistry of a shallow subtropical estuary through strong resuspension | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article The impact of a major hurricane on sediment geochemistry of a shallow subtropical estuary through strong resuspension Jianhong Xue, Zucheng Wang, Xianbiao Lin, Kaijun Lu, Sarah Douglas, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4572090/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 Oct, 2024 Read the published version in Estuaries and Coasts → Version 1 posted 5 You are reading this latest preprint version Abstract Major hurricanes can greatly affect sediment biogeochemical processes in coastal bays and estuaries through strong storm surges and resuspension, yet the impacts on sediment geochemistry have rarely been evaluated. Here the sediment geochemistry of the Mission Aransas Estuary, Texas, was systematically evaluated prior to and after Hurricane Harvey, a Category 4 storm. The median grain size of the surface sediments in the estuary significantly increased, but the bulk sediment total organic carbon content (TOC%) remained relatively constant. The concentration and composition of several organic chemical classes in the sediment were altered in distinctly different patterns. Accessory pigments showed that cyanobacterial materials in surface sediments increased immediately after Harvey, but returned to pre-Harvey levels five months post-hurricane. Pheophorbide decreased significantly after Harvey, but also recovered within seven months, suggesting resilience of the benthic community. In contrast, polycyclic aromatic hydrocarbons (PAHs) and n -alkanes decreased (5-10-fold) five months after Hurricane Harvey and remained low one year later. The loss of PAHs and n -alkanes from the sediment might be related to increased solubility due to decreased salinity and strong resuspension during the storm surge. Overall, the strong storm surge and resuspension of sediment by Hurricane Harvey presented a major disturbance to the geochemistry of surface sediment in the MAE, but the impact on individual organic chemical classes depended on their sources, chemical properties, and/or association with fine clay minerals. Hurricane Harvey Estuary Sediment resuspension Grain size Pigments PAHs and n-alkanes Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Introduction The intensity and frequency of tropical cyclones in the North Atlantic basin have increased since the mid-1990s (Webster et al. 2005 ), as illustrated by a rapid rise in the frequency of tropical cyclones striking the Mid-Atlantic and the Gulf of Mexico coasts. In the past 20 years, three 500-year flood events have impacted coastal North Carolina following Hurricanes Floyd (1999), Matthew (2016) and Florence (2018) (Paerl et al. 2001 ; 2006 ; 2018a ; 2019 ), and even more severe flooding occurred along the Gulf of Mexico during the catastrophic 2017 Atlantic hurricane season, which included Hurricanes Harvey, Maria, and Irma. Recently, Paerl et al. ( 2019 ) examined a 120-year precipitation record for the North Carolina coast, which revealed that 6 out of the 7 “wettest” events were tropical cyclones that occurred only in the past 20 years. These events severely impact estuarine ecosystems, which play vitally important cultural and economic roles (Emanuel 2005 ; Greening et al. 2006 ). Estuarine health has already been greatly influenced by human activities, such as excessive inputs of nutrients that promote harmful algal blooms, hypoxia, and finfish and shellfish kills (Paerl et al. 1998 ; Eby and Crowder 2002 ; Adams et al. 2003 ; Paerl et al. 2006 , 2014 , 2018b ). Therefore, there is a critical need to better understand how estuarine ecosystems would respond under the projected scenarios of climate change and anthropogenic disturbance across geographic and climatic gradients. Particularly, it remains largely unknown how coastal environments are impacted after landfalls of major hurricanes due to the lack of relevant data, as both pre- and post-hurricane data are needed for such evaluation. Hurricane landfalls substantially disturb estuarine and coastal ecosystems, mainly through strong wind, storm surge, heavy precipitation, flooding, and saltwater intrusion (Paerl et al. 2001 ; Hogan et al. 2020 ). Depending on the estuarine water flushing time, the return time of the water quality (such as salinity and nutrient concentrations) to pre-storm conditions can vary from days to months (Patrick et al. 2020 ; Walker et al. 2021 ). In a short (2–3 days) residence time system such as Waquoit Bay, a shallow bay near Cape Cod, Massachusetts, the salinity of surface water slightly dropped from 31–32 to < 25 after Hurricane Bob but quickly returned to pre-storm condition in ~ 7 days (Valiela et al. 1998 ). In a system with longer water residence time such as North Carolina’s Neuse River Estuary-Pamlico Sound (2–6 months, Cooper et al. 2004 ), it could take up to ~ 8 months for salinity to return to pre-storm condition (Peierls et al. 2003 ). These impacts on water quality might consequently affect phytoplankton communities in estuaries and bays, further affecting primary production and nutrient cycling for a longer period (Paerl et al. 2001 ; Glibert et al. 2009 ). In addition, hurricanes often lead to sediment resuspension, erosion, and subsequent deposition, which alter the concentration, composition, and physicochemical properties of surface sediments in coastal and inner shelf areas (Goñi et al. 2006 ; Breithaupt et al. 2020 ). This also likely influences the benthic faunal community. For example, immediately following major hurricanes in the Cape Fear Estuary, North Carolina, significant declines in the total benthic community (dominated by opportunistic species) abundance were observed, and the recovery to pre-storm levels took ~ 3 months or longer (Mallin et al. 1999 ). Finally, hurricanes may directly transport new contaminants into sediments of coastal areas from local sources through flow caused by heavy rains (Greening et al. 2006 ), resulting in high concentrations of contaminants, such as dichloro-diphenyl-trichloroethane (DDT), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in coastal sediments (Johnson et al. 2009 ; Romanok et al. 2016 ). These contaminants could also be redistributed via physical disturbance on sediment in the estuary and coastal regions. After Hurricanes Katrina and Rita in 2005, layers of organic carbon- and mercury-enriched fine grain sediments were redistributed over the northern Gulf of Mexico continental shelf through the Mississippi-Atchafalaya River system (Liu et al. 2009 ). Therefore, the landfall of a hurricane may change not only the water quality but also the geochemistry of surface sediments in the impacted estuaries and coastal areas over a longer time scale. The impact of hurricanes on sedimentary organic carbon (OC) of estuarine and coastal systems has been widely studied. Goñi et al. ( 2006 ) reported that a storm layer enriched with fine muds and higher organic content was formed one week after Hurricane Lili (2002) along the inner Louisiana shelf at ~ 20 m water depth, but not at depths < 10 m. They proposed that the elevated OC level in these relatively offshore sediments (0.3–0.9 wt% pre-hurricane, 0.7–1.7 wt% post-hurricane) was most likely contributed by the settling and deposition of the finer fraction of the resuspended seabed sediments. However, it was also reported that OC concentrations did not change in the sediments of Lake Pontchartrain and Mississippi Sound two months after Hurricane Katrina in 2005 (Macauley et al. 2010 ), or those in the Neuse River Estuary one month following the passage of three hurricanes (Balthis et al. 2006 ). Although the bulk OC content remained relatively constant in these examples, the source or composition of OC in the estuary sediment might have changed after the hurricanes. There have been a limited number of studies that focus on specific compounds classes, such as labile organic carbon (i.e., amino acids and pigments) or petroleum-sourced contaminations (i.e., PAHs and n -alkanes) inside the estuary, which could be used to provide information about changes in OC source in sediments. Amino acids and pigment can be used to indicate the lability or source of organic matter (Liu and Xue 2020 ), while PAHs and n -alkanes indicate the level of environment contaminants that are often of concern after hurricanes. Hurricane Harvey, as a category 4 storm, made landfall ~ 15 km north of the Port Aransas in south Texas on August 25, 2017 (Fig. 1 ). It was the first major hurricane to land in the US since 2005, and the strongest in Texas since Carla (1961). Wind gusts in Port Aransas reached 212 km h − 1 (Weather Prediction Center, NOAA), and the eye wall moved directly over the Mission-Aransas Estuary (MAE), a shallow estuarine system isolated from the open Gulf of Mexico by sandbar islands. While the extremely strong winds and powerful storm surge caused by Harvey directly hit the MAE, widespread flash flooding mostly occurred to the northeast of the storm. The Houston metropolitan area received more than 75 cm of precipitation, in contrast with only ~ 10 cm of precipitation in Port Aransas (Source: National Hurricane Center, NOAA) (Blake and Zelinsky 2018 ). Therefore, there was clearly a spatial decoupling between the major impacts from wind and flood of Hurricane Harvey on the Texas coast (Patrick et al. 2020 ). Hurricane Harvey offered a serendipitous opportunity to evaluate the impacts of a major hurricane on sediment biogeochemistry of an estuarine system. Given the strong winds and storm surge caused by Hurricane Harvey, we hypothesized that the sediment biogeochemistry of the shallow MAE was severely affected and that these effects would last for months or years. Surface sediments from 19 sites across the MAE (Fig. 1 ) were initially collected in June 2017 as pre-Harvey baseline data, followed by sampling every two or three months from October 2017 to March 2019 over a period of 1.5 years as post-Harvey observations. A series of geochemical parameters were analyzed in these sediment samples, including sediment grain size, bulk OC and its δ 13 C org , chloro-, and accessory pigments, hydrolyzable amino acids, PAHs, and n -alkanes (C 8 -C 33 ). Analyses of PAHs and n -alkanes were completed only through March 2018. These parameters allowed a comprehensive evaluation of the impacts of Harvey on sediment geochemical processes from multiple levels, including bulk perspectives and specific compound classes that may have been impacted differently by the hurricane depending on their sources and association with minerals. Materials and Methods Site Description The Mission Aransas Estuary (MAE) includes the Mission and Aransas rivers, and the Copano, Aransas, and Mesquite Bays, and is bordered by San Jose Island. The MAE is part of the Mission Aransas National Estuarine Research Reserve (MA-NERR), which has continuously monitored physical and water quality parameters at five System-Wide Monitoring Program (SWMP) stations (CW, CE, AB, MB, and SC; Fig. 1 ) since 2007. The MAE has limited exchange with the coastal Gulf of Mexico due to a microtidal range and limited inlet flushing, and the water residence time is estimated to be 1–3 years on average (Armstrong 1982 ; Solis and Powell 1999 ). The shallow water depth of Copano and Aransas Bays, with an average of 2 m (Armstrong 1987 ; Orlando 1993 ), results in strong benthic-pelagic interactions, such as nutrient regeneration and the influence of the benthos on the water column. The shallow water depth also makes it ideal to evaluate the effects of winds and storms on estuarine sediment geochemistry. Sample Collection Sediments were collected using acrylic core tubes (8.2 cm outer diameter, 7.6 cm inner diameter, and 30.5 cm in length) from 19 sites (S01-S20; collection at S14 unsuccessful because S14 was inside the ship channel, which turned out too deep for hand core to reach the bottom) in the MAE (Fig. 1 ). At each site, three cores were collected, and the surface layer (0–5 cm) of each core was sectioned on deck. The three surface sections were combined and homogenized as a composite sample and stored in a cooler on ice. The samples were transported back to the lab within the same day and kept at -80°C in a freezer until analysis. The pre-Harvey samples were collected on June 8–9, 2017, two months before Hurricane Harvey made landfall; and the post-Harvey samples were collected on October 17–18, 2017 (53 days after landfall). In 2018, samples were collected on January 29–30, March 29-April 8, June 21–22, August 30–31, and November 14–15. A final sampling was taken on March 6–7, 2019, 1.5 years after the hurricane. Additional two layers (5–10 and 10–15 cm) of sediments were collected at site S09 in June 2017 and October 2017 only. For each sediment sample collection, corresponding surface (~ 0.1 m depth) water for inorganic nutrient analysis was also collected with acid-washed opaque polyethylene bottles, placed on ice and transported to the lab within the same day. Water samples were filtered through 0.7 µm pre-combusted glass fiber filters (GF/F) and stored frozen (-20°C) until analysis. In addition, water quality data, including temperature, salinity, and turbidity, have been continuously measured every 15 min onsite at the five SWMP stations since 2007, and the data are ​​also available online ( http://cdmo.baruch.sc.edu ). Daily river discharge data for Mission River (gage 08189500) and Aransas River (gage 08189700) during 2017–2019 were obtained from the United States Geological Survey ( https://waterdata.usgs.gov/nwis ). Nutrient analyses Dissolved inorganic nitrogen (nitrate (NO 3 − ), nitrite (NO 2 − ), ammonium (NH 4 + )) concentrations were determined using a SmartChem Chemistry Analyzer with standard EPA colorimetric methods ( https://wrrc.unh.edu/analytical-instrumentation ). Mineral grain size The grain size of surface sediment was measured by a laser particle size analyzer (S3500; Microtrac Inc., Montgomeryville, PA, USA) based on a method modified from Gee and Or ( 2002 ). Briefly, ~ 0.2 g of unground sediment sample was mixed thoroughly with 15 mL of H 2 O 2 (1:2 v:v, H 2 O 2 :H 2 O) for 5 min to remove organic matter. Ten mL HCl (1:2, HCl:H 2 O) was then added to the bottle, and the bottle was incubated in a thermostat water bath at 40°C for 24 h to remove calcareous minerals. After incubation, 10 mL Nanopure water was added, and the bottle stayed still until the sediment had visually settled to remove Cl ions. The overlying water was gently removed by pipetting without disturbing the sediment. Another 10 mL Nanopure water was added to the bottle and the overlying water was removed by repeating the same procedure. Afterward, 10 mL (NaPO 3 ) 6 solution (0.5 mol L − 1 ) was added to the bottle. The whole bottle was shaken for 15 min in an ultrasonic shaker before analysis. The detectable grain size range for this analyzer was from 0.02 to 2000 µm. Organic carbon, nitrogen, and the carbon stable isotope δ 13 C org Total organic carbon (TOC), total nitrogen (TN), and the stable carbon isotope δ 13 C org in surface sediments were measured by a CHN elemental analyzer coupled with a Thermo Delta V Plus isotope ratio mass spectrometer. Samples were fumigated with concentrated hydrochloric acid in a sealed container for 24 h to remove carbonates prior to analysis (Hedges and Stern 1984 ). Precision for C and N was within 5% and for δ 13 C org was within 0.2‰. Pigment analysis Both chloro- and accessory pigments in surface sediments were analyzed chromatographically. Approximately 2 g of frozen sediment was transferred into a 15 mL polypropylene centrifuge tube, and 3 mL acetone was added for pigment extraction (Sun et al. 1991 ). The mixture was sonicated for 15 min, and then centrifuged for another 10 min. The acetone extract was siphoned with a glass pipette and filtered with a syringe filter (0.2 µm Nylon). The remaining sediment in the centrifuge tube was extracted again by the same procedure, and the two extracts were combined. Pigments in the extract were quantified using high performance liquid chromatography (HPLC) according to Liu and Xue ( 2020 ). Briefly, five specific chloropigments, including chlorophyll a (Chl a ), chlorophyll b (Chl b ), divinyl chlorophyll a (DVChl a ), pheophorbide a (Phide) and pheophytin- a (Phytin) were identified using a fluorescence detector attached to the HPLC. Seven carotenoids, including peridinin (Peri), 19’-butanoyloxyfucoxanthin (19-but), fucoxanthin (Fuco), prasinoxanthin (Pras), 19’-hexanoyloxyfucoxanthin (19-hex), alloxanthin (Allo), and zeaxanthin (Zea) were also quantified using a photodiode array detector attached to the HPLC. The water contents were considered in each sediment sample in order to obtain pigments concentrations on a dry sediment basis. The carotenoids were used to construct the phytoplankton community based on established algorithms (Letelier et al. 1993 ; Lambert et al. 1999 ; Qian et al. 2003 ). Duplicate analyses of the same extract generally agreed within 20%. Total hydrolyzable amino acids (THAA) Approximately 0.5 g of freeze-dried sediment was transferred into glass tubes containing 5 mL 6 N HCl, sealed under nitrogen gas, and then hydrolyzed at 110°C for 20 h. The hydrolyzed solutions were dried with nitrogen gas and replaced with deionized (DI) water, and then the hydrolyzed amino acids were analyzed using HPLC after being derivatized by o -phthaldialdehyde following Liu and Xue ( 2020 ). Sixteen amino acids were quantified through comparison with an authentic standard mixture (Sigma), which includes aspartic acid (ASP), glutamic acid (GLU), histidine (HIS), serine (SER), arginine (ARG), glycine (GLY), threonine (THR), β-alanine (BALA), alanine (ALA), tyrosine (TYR), γ-aminobutyric acid (GABA), methionine (MET), valine (VAL), phenylalanine (PHE), isoleucine (ILE), and leucine (LEU). Duplicate analyses of amino acids from the same extract generally agreed within 10%. Polycyclic aromatic hydrocarbons (PAHs) and n -alkanes Surface sediment 16 US EPA priority PAHs and n -alkanes in the range of C 8 -C 33 were analyzed. PAHs with 2 benzene rings (naphthalene, acenaphthene, acenaphthylene, and fluorene) and 3 rings (phenanthrene and anthracene) were defined as low molecular weight (LMW), and those with 4–6 rings including fluoranthene, pyrene, benzo[a]anthracene, and chrysenebenzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3]pyrene, dibenzo[a,h]anthracene, and benzo[g,h,i]perylene were defined as high molecular weight (HMW). Briefly, ground freeze-dried sediments (4 g) mixed with surrogate standards (phenanthrene-d10 and hexadecane-d34) were extracted by accelerated solvent extraction (ASE-350) using a mixture of acetone and dichloromethane (1:1, v/v) (Wang et al. 2012 ). The extraction cells were heated to 100°C until the pressure of 10 MPa was reached. The static time was 10 min, the flush volume was 60%, and the purge time was 90 s. The final volume of the extract was ca. 30–40 mL, which was further concentrated with hexane to about 1 mL by a rotary evaporator. The concentrated extract was purified with a chromatographic column, which was packed with activated silica (6 g, 100–200 mesh, activated at 160°C for 16 h) and topped with 1 g of anhydrous sodium sulfate (baked at 450°C for 4 h). After the column was conditioned with 20 mL hexane, the extract was added to the top of the column and eluted with 12 mL hexane, which was collected for n -alkane analysis. The column was further eluted with 15 mL dichloromethane/hexane (1:1, v/v), which was collected for PAH analysis. The eluents were reduced to 1 mL by a rotary evaporator and transferred to a 2 mL glass vial, preserved in a freezer at -20°C until gas chromatography–mass spectrometry (GC-MS) analysis. A GC-MS with a Rxi-5Sil column (30 m × 0.25 mm; 0.25 µm film thickness) was used to measure the 16 PAHs and n -alkanes. The scanned mass over charge (m/z) ratios ranged from 127 to 279 for PAHs, and 57 and 71 for n -alkanes. For PAH analysis the oven temperature was held at 40°C for 4 min, increased to 280°C at a rate of 10°C min − 1 and held for 4 min, then increased to 300°C at a rate of 10°C min − 1 and held for 5 min. For n -alkanes the oven temperature was held at 70°C for 4 min, and increased to 290°C at a rate of 10°C min − 1 , then held for 40 min. The injector and detector temperatures were both 250°C. The injection volume was 1 µL in a splitless mode. The recovery rates of the surrogates ranged from 60–110%. Negligible PAHs were detected in our method blank. The detection limit for PAHs and n -alkanes were 0.01 ppm and 0.1 ppm, respectively. An external standard was used to calculate the concentrations of the PAHs and n -alkanes. Statistical analysis A two-way ANOVA followed by the Tukey-Kramer test was performed for each variable, seeking statistical significance among sampling events. A Student’s t - test was performed to determine statistical significance among the sampling sites. Principal component analysis (PCA) was applied on composition data of THAA using MATLAB (Xue et al. 2011 ). All statistical analyses were performed with MATLAB R2019a. Results Water quality changes in the MAE after Hurricane Harvey The landfall of Harvey on San Jose Island and its passage through the MAE caused strong winds and a major storm surge in this estuarine system (Blake and Zelinsky 2018 ). The heavy precipitation in the southeastern Texas coastal area enhanced the discharge of the Mission and Aransas rivers for about 2 weeks after Harvey (Fig. 2 a). The increased freshwater inflow led to a drastic decrease in salinity in the MAE after Harvey. In Copano Bay (station CW, Fig. 2 b), salinity dropped rapidly from 22.9 on August 24 to 3.3 on September 4, and it took ~ 8 months to slowly return to 22.9, the pre-Harvey level. In contrast, the daily turbidity average at this station increased instantly from 20 nephelometric turbidity units (NTU) on August 24 to 775 on August 26, but decreased rapidly back to < 20 within 1 week on August 30 (Fig. 2 b). This suggests that particles were abruptly suspended in the water column, likely caused by storm surge, waves, and wind, and then decreased to background levels within 1 week (Lou et al. 2016 ). Most of the suspended particles either quickly settled back into the sediment or were transported laterally via storm surge after the hurricane. Concentrations of dissolved nitrates (NO 3 − plus NO 2 − ) in surface water at these 19 sites were low (0.8 ± 0.3 µM) in both Copano and Aransas bays before Harvey, but increased to 1.9 ± 3.1 µM in October 2017, likely due to the increased river discharge after Harvey (Wei et al. 2022 ). The nitrates level increased again in June 2018 due to enhanced river discharge by heavy precipitation (Fig. 2 a), with 3.1 ± 2.1 µM on average (4.7 ± 2.2 µM in Copano Bay and 1.8 ± 0.5 µM in Aransas Bay). The concentration of NH 4 + was 1.5 ± 0.7 µM before Harvey, slightly dropped to 0.8 ± 0.6 µM after Harvey in October 2017, but increased back to 3.5 ± 2.4 µM in June 2018. Mineral grain size of surface sediments The sediment was categorized into three groups based on grain size: sands (63-2000 µm), silts (4–63 µm), and clays (0.02-4 µm). The MAE sediment was dominated by sands and silts, as clays generally accounted for only ~ 2% of the total for both pre- (June 2017) and post-Harvey (every two or three months from October 2017 to March 2019). Thus, only sand and silt fractions are reported here (Table 1 ). The pre-Harvey sediments were dominated by silts (70 ± 12%), except for sites S06 and S16 (both are in bay-margin areas), which were dominated by sands, accounting for 94% and 72% of the total, respectively. In October 2017 post-Harvey, these two sites were still dominated by sands, with a percentage of 81% and 86%, respectively. Slight variations on the silt percentages (67 ± 13%) were observed for all other sites, except that site S13 was completely changed from silts (67%) into sands (99%). In March 2018, another site (S20) was also observed turning completely into sand (100%). By March 2019, 1.5 years post-Harvey, the number of sand-dominated sites (i.e., sand% ≥ 65%) increased from two (i.e., S06 and S16) to four (i.e., with the addition of S13 and S20, sand 66% and 67% respectively). Silt fractions also slightly decreased (56 ± 9% silt) at the other 15 sites. Table 1 Surface sediment fractions (%) for sand (63 ~ 2000 µm) and silt (4–63µm) at each sample site during pre-Harvey (June 2017) and post-Harvey (October 2017 to March 2019) in the Mission-Aransas Estuary in south Texas. Stations Sediment fractions (%) Sand (63-2000 µm) Silt (4–63 µm) Jun-17 Oct-17 Jan-18 Mar-18 Jun-18 Aug-18 Nov-18 Mar-19 Jun-17 Oct-17 Jan-18 Mar-18 Jun-18 Aug-18 Nov-18 Mar-19 S01 19 43 49 34 41 53 62 56 79 57 51 65 59 47 38 44 S02 19 41 49 23 26 43 48 39 79 59 51 76 74 60 52 61 S03 33 26 45 37 29 39 38 42 66 73 55 62 71 61 62 58 S04 24 23 26 42 32 23 35 32 74 76 74 57 67 77 63 67 S05 18 21 22 31 49 21 28 30 80 78 77 69 51 78 71 69 S06 94 81 100 100 100 91 100 95 6 19 0 0 0 9 0 5 S07 56 29 33 39 48 43 50 56 44 70 67 61 52 56 50 44 S08 31 23 37 29 - 52 22 51 67 77 62 70 - 48 77 49 S09 24 17 35 30 30 13 20 37 75 81 64 69 70 87 79 63 S10 28 21 45 40 39 51 15 43 70 79 54 59 60 49 85 57 S11 19 30 22 12 31 25 30 32 79 69 77 87 67 74 69 67 S12 19 29 47 38 48 32 47 44 78 71 52 61 51 67 52 56 S13 33 99 87 67 88 79 72 66 67 1 13 33 12 21 28 34 S15 37 52 58 - 45 63 55 51 62 45 42 - 55 37 45 49 S16 72 86 62 82 87 100 100 79 28 14 38 18 13 0 0 21 S17 16 8 37 37 30 56 29 51 79 82 62 60 69 40 70 49 S18 42 33 59 27 62 52 56 54 56 66 41 72 38 48 44 46 S19 15 49 43 - 41 43 22 33 82 51 56 - 58 56 76 67 S20 51 57 59 100 63 67 50 67 47 43 41 0 37 33 49 33 Median grain size, the midpoint of sediment size distribution by weight, is another way to quantify the size change of sediment particles. From June 2017 to March 2019, the median grain size sharply increased at site S13, from 60 µm in June 2017 to 134 µm in October 2017, but then decreased to 101 µm in March 2019 (Fig. 3 ). A similar trend was observed at site S19, which had a median grain size of 30 µm in June 2017, increased to 88 µm in October 2017, and then decreased to 54 µm in March 2019. A sharp increase in median grain size was also observed at site S20 in March 2018 (164 µm), which then later decreased to 97 µm in March 2019. By March 2019, the four sand-dominated sites (i.e., S06, S13, S16, and S20) had a notably higher median grain size (119 ± 28 µm) than the other 15 non-sand dominant sites (70 ± 15 µm) ( p = 0.0001). Overall, even though the average median grain size did not significantly increase over the 19 sites between June 2017 (57 ± 31µm) and October 2017 (66 ± 35µm), sediment became significantly coarser in January, June, August of 2018 and March 2019 (i.e., 79 ± 32µm, 83 ± 37µm, 82 ± 38µm, and 80 ± 27 µm, respectively), compared with that in pre-Harvey (57 ± 31 µm) (Fig. S1 , p < 0.05). Almost 1.5 years after Harvey, the median grain size of the surface sediment remained significantly different from what it was before Harvey. Concentrations of total organic carbon (TOC%) and δ 13 C org The average TOC% in surface sediments at the 19 sites ranged from 0.7–0.9%, and there was no significant difference between pre- and post-Harvey samples ( p > 0.2, Fig. 4 a). At specific sites, however, there were large variations among different sampling periods. For example, at S05, TOC% was 0.43% in June 2017, doubled in March 2018 (1.2%), and then dropped to 0.75% in March 2019. At S01, TOC% was high (1.2%) in June 2017, then dropped to 0.79% in March 2018 and 0.50% in March 2019. Moreover, large variations of TOC% were observed spatially even in the same month, and the TOC% values were negatively correlated with the median grain size (Fig. 5 , p < 0.0001), indicating that TOC was associated mainly with finer minerals (i.e., smaller grain size). Consistently, the TOC% at four sand-dominated sites (i.e., S06, S13, S16, and S20, all with an average sand fraction > 60%, Table 1 ) was 0.27 ± 0.18%, significantly lower than those of the remaining 15 sites (0.87 ± 0.30%) ( p < 0.0001). However, there were no significant changes of TOC% between pre-Harvey and post-Harvey samples for either group (i.e., the four sands-dominated sites or the remaining 15 sites). The δ 13 C org value was − 20.6 ± 1.0‰ pre-Harvey in June 2017, became more depleted in October 2017 (-21.5 ± 1.2‰) after Harvey ( p = 0.02), but then returned to pre-Harvey levels when samples were further collected in January 2018, March 2018, and March 2019 (-19.9 ± 0.9, -20.2 ± 0.7, and − 19.9 ± 1.4‰) (Fig. 4 b). Specifically, the depletion in δ 13 C org in October 2017 was driven mostly by samples at sites S05 (-23.0‰), S06 (-24.1‰), S15 (-23.0‰), and S16 (-23.3‰). In June 2018, the δ 13 C org value (19.3 ± 1.2‰) became relatively enriched among all the sampling events. Total pigments and phytoplankton community The averaged total pigments in surface sediments ranged from 1.6–4.6 µg g − 1 , with lowest values in January 2018 and highest values in March 2019 (Fig. 4 c). Among the 19 sites, higher pigment concentrations (> 3.0 µg g − 1 ) occurred in eastern Copano Bay (S03, S04, S05, S07, S08, and S09) and upper Aransas Bay (S11, S17, and S19). Lower pigment concentrations (< 1.2 µg g − 1 ) were observed in sand-dominated sites (S06, S13, S16, and S20). For all samples combined, ~ 70% of the total pigments were chloropigments, with the remainder as carotenoids. According to accessory pigment algorithms developed for this region (Reyna et al. 2017 ; Douglas et al. 2023a ), cyanobacteria, diatoms, and cryptophytes were the major algal groups, contributing about 90% of the total community (Fig. 6 ). However, the abundance of cyanobacteria was significantly higher in October 2017 (72 ± 10%) than any other sampling period (second highest 57 ± 9% in March 2019, p < 0.05), indicating that cyanobacteria may have become the dominant algal group in the water column immediately following Harvey, but then declined over time. By March 2019, the abundance of cyanobacteria (57 ± 9%) was still significantly higher than it was pre-Harvey (45 ± 13%, p < 0.05). In contrast, the abundance of diatoms was significantly lower in October 2017 (14 ± 12%), and remained low through June 2018 (highest 15 ± 18% in June 2018), compared to the pre-Harvey level in June 2017 (27 ± 15%, p < 0.05). Approximately 60% (in molar units) of the chloropigments were Chl a , 10% pheophorbide, and the other 30% pheophytin (Fig. 7 ). The average composition of the chloropigments remained relatively constant over time, but there were significant changes in the proportion of pheophorbide right after Harvey. The concentration of pheophorbide dropped roughly 7-fold from 0.28 µg g − 1 in June 2017 to 0.038 µg g − 1 in October 2017 (Fig. S2b), corresponding to a drop from 15–4% in composition. The level of pheophorbide in October 2017 was the lowest among all the sampling periods (Fig. 7 ). However, the abundance of pheophorbide recovered quickly in January 2018 (12%) and March 2018 (15%), and the concentration recovered in March 2018 (0.20 µg g − 1 ; Fig. S2b), seven months after Harvey. Total hydrolyzed amino acids (THAAs) The concentrations of THAAs at the 19 sites dropped greatly from 5.1 µmol g − 1 in June 2017 to 2.7 µmol g − 1 in October 2017 after Harvey, then slowly increased, peaking in June 2018 (5.1 µmol g − 1 ), which was comparable to that of June 2017 (Fig. 4 d). Throughout the sampling period, THAA concentration at sand-dominated sites (S06, S13, S16, and S20) was 3.1 ± 1.5 µmol g − 1 , significantly lower than those at the other 15 sites (4.2 ± 1.9 µmol g − 1 ) ( p = 0.002). Overall, THAA-C contributed 3 ± 2% of organic carbon in surface sediments, but it contributed more at the sand-dominated sites (11 ± 8%). ASP, GLY, and ALA were the most abundant amino acids at all sites, and they accounted for 40% of the total amino acids (Fig. S3). Principal component analysis (PCA) was performed on the THAA compositional data, with the first two PCs shown in Figure S4. Most of the pre-Harvey samples (June 2017) were enriched in SER, GLY and THR, indicative of sources from diatoms (Sheridan et al. 2002 ), while the post-Harvey (i.e., October 2017) samples were located on the opposite direction along the first PC, enriched with PHE, HIS and ILE. This suggests a sudden composition shift immediately after Harvey. However, the THAA composition in June 2018 was highly similar to those reported pre-Harvey (June 2017), suggesting that THAAs in sediments had fully recovered one year after Harvey. Polycyclic aromatic hydrocarbons (PAHs) The PAHs were only analyzed in June 2017 (pre-Harvey) through March 2018 (post-Harvey) (Fig. 4 e). The concentrations of PAHs in surface sediment pre-Harvey were 436 ± 303 ng g − 1 , with large variations among the 19 sites. These concentrations were correlated with n -alkanes (r 2 = 0.61, p = 0.0001; Fig. S5a), and TOC% (r 2 = 0.36, p = 0.007; Fig. S5b). Fine particles (median grain size < 63 µm) tended to have higher levels PAHs except at site S07, which was unusually high (1401 ng g − 1 ) (Fig. S5c). The average concentrations of PAHs decreased 4-fold at the 19 sampling sites following Harvey in October 2017 (103 ± 66 ng g − 1 ), and further decreased 2-fold in January 2018 (50 ± 33 ng g − 1 ) (Fig. 4 e). The level of PAHs stabilized in March 2018 (66 ± 40 ng g − 1 ). The magnitude of change however differed greatly between HMW PAHs and LMW PAHs. The concentrations of HMW PAHs did not change much after Hurricane Harvey, whereas more than 90% of the decrease in October 2017 was attributed to the loss of LMW PAHs (Fig. 9 ). But neither LMW- nor HMW PAHs changed after January 2018. For the two additional layers (5–10 and 10–15 cm) of the sediment collected in site S09, PAHs were also decreased greatly following Harvey in October 2017 (Fig. S6). Consistently, 90% of the decrease was due to the loss of LMW PAHs. Total n -alkanes The n -alkanes were analyzed from June 2017 through March 2018 (Fig. 4 f). The concentrations of total n -alkanes in surface sediments were 12 ± 8.3 µg g − 1 pre-Harvey, with large variations among the 19 sites. Like PAHs, high n -alkanes concentrations also occurred in sediments with high TOC% (Fig. S5d) and low median grain size (Fig. S5e), which is consistent with earlier findings that TOC and specific organic compound classes tend to be concentrated in finer silt and clay fractions in sediments (Mayer 1994 ; Liu et al. 2013 ). The concentrations of n -alkanes decreased three-fold at all 19 sampling sites following Harvey in October 2017 (4.4 ± 2.9 µg g − 1 ), and further decreased two-fold in January 2018 (2.3 ± 1.7 µg g − 1 ). The concentrations of n -alkanes in March 2018 (2.8 ± 2.7 µg g − 1 ) were similar to those in January 2018, indicating that n -alkanes in surface sediment stabilized five months after the disturbance by Harvey. There was a slight difference in the n -alkanes composition throughout the sampling periods (Fig. 8 ). Before Harvey in June 2017, n -alkanes exhibited a unimodal distribution pattern, centering at C 12 -C 21 as the predominant compounds, with C 16 as the most abundant. Moreover, the short-chained n -alkanes were dominated by even-numbered compounds, yet the long-chained n -alkanes were dominated by odd-numbered compounds. After Harvey, in October 2017, total n -alkanes showed a bimodal distribution pattern centered at C 14 - C 21 and C 25 - C 31, maintaining the even and odd predominance, respectively. There was a reduction in C 16 levels, countered by increased percentages of both the short-chain even hydrocarbons (C 14 , C 18 , and C 20 ), and the long-chain odd hydrocarbons (C 27 , C 29 , and C 31 ). In January and March of 2018, although bimodal distribution remained, the n -alkane C 16 was no longer the dominant hydrocarbon. The short-chain even hydrocarbons (C 18 and C 20 ) also decreased, alongside an increase in long-chain odd hydrocarbons (C 29 and C 31 ). By March 2018, C 31 was the most abundant n -alkane, and the short-chain n -alkanes were no longer dominated by even ones. Discussion Surface sediment grain size generally increased across the MAE after Harvey Hurricane Harvey’s landfall on San Jose Island and passage over the MAE led to an unprecedentedly strong storm surges in the affected region. While heavy precipitation enhanced terrigenous matter input from the rivers, storm surge from the seaward direction greatly impacted the MAE (Blake & Zelinsky 2018 ). Water turbidity caused by the storm surge reached as high as 1300 NTU in Copano Bay West on August 26, 2017, the highest recorded since this MA-NERR SWMP station was established in 2007, though it quickly decreased to 100 NTU by August 30, 2017. The dramatically increased water column turbidity, associated with high concentrations of particles including minerals, indicated strong sediment resuspension, and further transport and/or redistribution of particles in this area. For example, a strong current outflow as high as 2.0 m s − 1 along the Lydia Ann Channel (Fig. 1 ), accompanied by erosion along the bayside shoreline of San Jose Island, were observed during Hurricane Harvey (Goff et al. 2019 ). After surface sediments in the impacted area were resuspended, the settling and transport of finer and coarser particles may have been subject to different transport modes, causing some dynamic sorting to take place depending on particle size and physical energy (Dyer 1995 ). Smaller-sized particles were more likely transported to the coastal Gulf of Mexico with the strong outflow via the Lydia Ann Channel, while the relatively large-sized particles likely resettled in the local estuarine surface sediments. As a result, the lower side of the Aransas Bay, including sites S12, S13, S15 and S16, immediately became coarser following Harvey in October 2017 (Fig. 3 ). Note that both the Mission and Aransas rivers experienced a large discharge event again on June 19–20, 2018 (Fig. 2 a), and the lower side of the Aransas Bay also became coarser correspondingly, though turbidity level were not notably different after that event. This indicates that, in the MAE, river flooding events alone may also likely to produce discharges strong enough to carry the fine particles away from the estuary, as compared with the extreme wind-driven waves and strong storm surges brought by Harvey. In Galveston Bay, located ~ 250 km northeast of the MAE, following Harvey, as much as 48 cm of coastal erosion followed by 22 cm of new sediment deposition were observed inside the San Jacinto Estuary, equivalent to about 18 years of average sediment loads delivered into Galveston Bay following the storm (Du et al. 2019 ). Li et al. ( 2015 ) reported that on the inner shelf of the Eastern China Sea during Typhoon Morakot in 2009, large amounts of fine particles in seafloor sediments were resuspended into the water column, resulting in much coarser sediments following the typhoon. Other studies have also documented that major hurricane affected coastal landscapes, especially salt marsh sediments, by eroding, redistributing, and depositing sediments via waves and storm surges (Bera et al. 2018 ). From the time-series observations of this study, the median grain size of the MAE surface sediment remained coarser 1.5 years after Harvey, and there was no clear seasonal pattern. A much longer time may be needed for the grain size to recover to pre-Harvey levels considering the extremely low base flows from the Mission and Aransas rivers to this system (Mooney and McClelland 2012 ; Reyna et al. 2017 ). It is also possible that the median grain size will remain at a new, higher baseline. Further monitoring is needed to evaluate whether median grain size can recover to the level of pre-Harvey. OC% in surface sediment showed resistance to Harvey Averaged across the 19 sampling sites, the bulk TOC% in sediments did not change significantly in October 2017 after Harvey, and there was no further change from January 2018 to March 2019 ( p > 0.05), even though the median grain size generally increased after Harvey. The loss of TOC through fine sediments due to particle resuspension and export to the Gulf of Mexico might be balanced by the input of terrestrial debris from river input and storm surge, and the newly produced autochthonous organic matter from the overlying water column. First, the δ 13 C org values became slightly depleted in October 2017 after Harvey, possibly indicating a source of terrestrial organic matter in the sediment. In particular, δ 13 C org values at both sites S15 and S16 were much more depleted in October 2017 (-23.0 and − 23.3‰, respectively) than in June 2017 before Harvey (-19.3 and − 20.6‰, respectively). These two sites are located on the bayside of San Jose Island, where strong seaward storm surges were observed during Harvey (Goff et al. 2019 ). Thus, when the seaward storm surge and current passed over the island, the terrestrial organic materials may have been carried away and redeposited to these nearshore sediments. Secondly, despite the strong resuspension and storm surge, phytoplankton biomass in the water column showed similar seasonal dynamics with the years before Harvey and was not significantly impacted by Hurricane Harvey (Douglas et al. 2023a ). Additionally, the THAA concentrations in both water column (Douglas et al. 2023b ) and sediment (Fig. 4 d) in June 2018 were very similar to them in June 2017, indicating a quick recovery of the autochthonous OC in the MAE. Therefore, the newly produced particles from the water column may have rapidly deposited into the sediment and replenished the lost organic matter. The unchanged OC% in surface sediment showed its resistance to storm disturbance. Changes of phytoplankton communities and chloropigments in sediments The microalgal community in the surface sediment, reconstructed from accessory pigments, reflects contributions from benthic microalgae and the algal material that recently settled from the water column. Therefore, the increase in cyanobacteria and decrease in diatom contributions in surface sediment immediately post-Harvey (Fig. 6 ), may indicate a similar shift in benthic microalgal and phytoplankton community in the water column, as confirmed by Douglas et al. ( 2023a ). They reported that a large amount of freshwater and nutrients were exported to the MAE after Harvey, which may have promoted cyanobacteria production in surface waters. Cyanobacteria blooms in low salinity waters have been reported previously after the passage of hurricanes (e.g., Paerl et al. 2001 ; Glibert et al. 2009 ). For example, in the historically oligotrophic Florida Bay after the passages of Hurricanes Katrina, Rita, and Wilma, large blooms of Synechococcus were sustained for 3 years (Glibert et al. 2009 ). Pheophorbide, a degradation product of Chl a , is mainly produced in zooplankton guts after algal cells are digested (Shuman and Lorenzen 1975 ; King and Repeta 1994 ; Lee et al. 2000 ; Chen et al. 2003 ). Pheophorbide has been used to quantify benthic macrofaunal grazing intensity in intertidal sediment (Ford and Honeywill, 2002 ). The concentrations and proportions of pheophorbide in surface sediments of the MAE substantially decreased in October 2017 after Harvey, suggesting that zooplankton and other benthic macrofaunal species may have been severely impacted by the strong storm surge and resuspension. Consistent with these results, Montagna ( 2023 ) reported that in San Antonio Bay, adjacent to the MAE, benthic macroinfaunal diversity, abundance, and biomass declined 54–82% immediately following Hurricane Harvey, and the benthos community shifted from polychaetes to mollusks, likely due to decreased salinity and depletion of dissolved oxygen (DO). High amounts of precipitation and large freshwater inflow decrease salinity, and the decomposition of high terrestrial organic loads can lead to low DO conditions in the estuary following a storm (Van Dolah and Anderson 1991 ; Mallin and Corbett 2006 ), which affect certain species and diversity of the benthic community. A significant decline in total benthic habitats (dominated by opportunistic species mostly polychaetes) was also observed in the Northeast Cape Fear River, North Carolina, immediately after Hurricanes Bertha and Fran in 1996, and low DO and its slow recovery was thought to be the major reason for this decline (Mallin et al. 1999 ). However, Hu et al. ( 2020 ) reported that the MAE did not experience a substantial DO decrease during and after Harvey, suggesting that the decline of benthic macrofaunal in the MAE was not related to hypoxic or anoxic conditions. Instead, it may have been due to either the significant reduced salinity (Montagna 2023 ), or the strong resuspension and storm surge that can greatly erode surface sediment and thus directly impact the benthic habitat. Previous work showed that increased turbidity and sedimentation could cause benthic smothering once sediment settles out of the water (Henley et al. 2000 ; Davies-Colly and Smith 2001). The benthic macrofauna in the MAE appears to be recovering 7 months after Harvey, as the proportion of pheophorbide in chloropigments increased back to 15% in March 2018. The recovery of the benthos within 7 months after Harvey’s landfall is consistent with the observation in San Antonio Bay (within 8 months) after Hurricane Harvey and in Cape Fear Estuary of North Carolina (benthos recovery generally in 2–4 months) after Hurricanes Bertha and Fran (Mallin et al. 1999 ), indicating high resilience of benthic infauna to hurricane disturbance. These results suggest that pheophorbide is an excellent indicator of the health of the benthic community in surface sediments. This conclusion, however, may need to be confirmed by directly comparing chloropigments and benthic population. Changes of surface sediment PAHs PAHs are a group of organic contaminants that are widespread in today’s environment, with pyrogenic (mainly combustion of fossil fuel) and petrogenic (petroleum products) as the two main sources (Laflamme and Hites 1978 ; Wang et al. 2001 ). PAHs are insoluble in water due to their high hydrophobicity, but strongly adsorbed onto particles and thus tend to be accumulated and preserved in sediments (Wang et al. 2001 ). The pre-Harvey levels of PAHs in the MAE surface sediment (436 ± 303 ng g − 1 ) were comparable to those in the Mississippi River mouth, salt marsh, and coastal shelf of the northern Gulf of Mexico (100–856 ng g − 1 , Wang et al. 2014 ), but much lower than those in highly industrialized and contaminated estuaries, such as the Passaic River (NJ, 145,000 ng g − 1 ) and the Newark Bay Estuary (44,000 ng g − 1 ) (Huntley et al. 1995 ), suggesting that the MAE is not heavily contaminated by PAHs. Consistent with many earlier studies (e.g., Oros and Ross 2004 ; Lubecki and Kowalewska 2010 ), higher PAH concentrations in sediment are often associated with fine particles (grain size < 63 µm) (Fig. S5c). However, the highest PAH concentration in this study (1401 ng g − 1 ) occurred at site S07, despite a sediment median grain size of 84 µm. This is likely because site S07 was close to the city of Rockport boat launch area, which likely produced higher levels of PAHs due to gasoline and diesel leaking or combustion (Li et al. 2003 ; Wang et al. 2014 ). In the MAE sediment, about 84% of PAHs were LMW prior to Harvey. Fossil fuels (e.g., diesel and gasoline, oil seeps, petroleum spills) tend to have more 2 to 3 ring LMW PAHs, while combusted fuels (e.g., vehicle exhaust, domestic heating with coal) are likely to contain more 4 to 5 ring HMW compounds (Van Metre et al. 2000 ). Therefore, the dominance of LMW PAHs in MAE before Harvey indicated a major petrogenic source. PAHs in MAE surface sediments significantly decreased to 103 ± 66 ng g − 1 following Harvey, compared to pre-Harvey levels (436 ± 303 ng g − 1 ). This decrease was likely caused by the strong physical disturbance inside the MAE, as fine particles, often enriched in PAHs, were resuspended from surface sediment, and then quickly flushed out of the MAE with a strong seaward outflow (Goff et al. 2019 ), as discussed above. The same magnitude loss of PAHs was also observed in lower sediment layers (5–10 and 10–15 cm) at site S09, indicating the physical disturbance on sediment could reach at least 10–15 cm below sediment surface or the surface layer may have lost due to the strong storm surge (Goff et al., 2019 ). Consistently, Liu et al. ( 2009 ) reported that following Hurricanes Katrina and Rita, fine organic carbon- and mercury-enriched sediments were substantially transported over the northern Gulf of Mexico continental shelf through physical redistribution, resulting in mercury input to the continental shelf approximately 5 times higher than its annual input from the Mississippi-Atchafalaya River system. In addition to the loss of finer minerals, the dramatic decrease in salinity in the MAE after Harvey, from 22.9 to 3.3, may have enhanced the solubility of PAHs (Oh et al. 2013 ; Means 1995 ; Turner 2003 ), particularly when fine sediment particles were resuspended to the water column. A large fraction of PAHs in the sediments may have been re-dissolved into the water phase, and then either exported out of the system due to tides and currents or degraded microbially and photochemically (Langworthy et al. 2002 ; Clark et al. 2007 ). The release of PAHs from sediments may affect organisms in coastal ecosystems. Dissolved PAHs in water generally have higher bioavailability than those associated with particles (Laor et al., 1998 ), which could lead to higher risk of toxicity to the aquatic life (Yan et al. 2018 ; Vijayanand et al. 2023 ), making this a potential impact of hurricanes on estuaries that deserves more research. The loss of total PAHs was mainly sustained by the decrease in LMW PAHs ( p < 0.001), whereas concentrations of HMW PAHs did not change significantly after the hurricane (Fig. 9 ). Preferential loss of LMW PAHs in oyster tissue has also been reported after Hurricanes Katrina and Rita in the Gulf of Mexico, suggesting that LMW and HMW PAHs respond differently to particle suspension and water salinity changes (Johnson et al. 2009 ). Different PAHs have different water solubilities and affinities for particles. Moreover, solubility decreases as molecular weight increases. Therefore, high-ring PAHs are more strongly bound by particles while low-ring PAHs have higher water solubility. Li et al. ( 2016 ) found that salinity had a more significant impact on the release behaviors of 2- and 3-ring PAHs than other individual PAHs species. In the low-salinity and high resuspension conditions following Harvey, LMW PAHs were preferentially dissolved in water and thus released from the sediment to water (Means 1995 ; Turner 2003 , Soclo et al. 2008 ). Since HMW PAHs in sediments did not change much after Harvey, the observed loss of total PAHs likely was a result of the release of LMW PAHs from sediments prompted by both sediment resuspension and the decrease in salinity. The monitoring of the LMW PAHs in the water column before and after a hurricane is needed in the future. Interestingly, PAHs further decreased to 50 ± 33 ng g − 1 in Jan 2018, and did not recover even seven months after Harvey in March 2018. The persistence of low levels of PAHs in the system suggests that it may take a much longer time to accumulate enough contaminants to reach pre-Harvey levels. This is reasonable as the MAE has a long water residence time (up to 3 years), and pre-Harvey PAHs in sediments might have accumulated for years, maybe decades, considering that PAHs are one group of persistent organic pollutants that resist environmental degradation. Changes of n -alkanes in surface sediments The concentration changes of n -alkanes in surface sediments were consistent with those of PAHs: a strong decrease immediately after Harvey followed by persistently low levels. Considering their similar hydrophobicity, n -alkanes may have been associated with the same types of sedimentary organic matter and size fractions of particles as PAHs in the MAE. However, considering that all alkanes are rather insoluble, the loss of fine particles via sediment resuspension might be the main cause for the decrease of n -alkanes after Harvey. Additionally, the sources of n -alkanes in sediments are more complex than PAHs. In addition to anthropogenic sources (i.e., petroleum contamination), n -alkanes in sediments have biological sources, such as bacteria, algae, and terrestrial plants (Gogou et al. 2000 ), which have different n -alkane compositions (Ahad et al. 2011 ; Frena et al. 2017 ). In general, n -alkanes derived from terrestrial plants have a strong odd-numbered predominance by long-chain compounds (C 25 -C 35 ) (Eglinton and Eglinton 2008 ). n -Alkanes sourced from bacteria, algae or phytoplankton, however, are dominated by short-chain compounds (C 12 -C 22 ), and have an even-numbered predominance, although they are much less common (Grimalt and Albaiges 1987 ; Elias et al. 1997 ). Petroleum oils consist of a highly complex mixture of hydrocarbons, and generally have a short-chain (C 15 -C 25 ) dominance on n -alkanes with no odd/even predominance (Connell et al. 1980 , 1981 ; Harb et al. 2003 ; Frena et al. 2017 ; Jafarabadi et al. 2018 ). Before Harvey, C 16 was the dominant alkane, which is an indicator of sediments contaminated with crude oil (Jafarabadi et al. 2018 ). However, n -alkanes dominated by petroleum compounds are usually identified by little or no odd/even predominance in the C 12 -C 25 range (Connell et al. 1980 , 1981 ; Frena et al. 2017 ; Jafarabadi et al. 2018 ). Our results showed the dominance of even-numbered C 14 -C 22 , with C 16 as the most abundant moiety, a pattern that instead indicated a diatom source (Elias et al., 2000 ). Bacterially-produced n -alkanes are also dominated by one or two even-numbered compounds in the C 12 -C 22 range, especially C 18 and C 20 (Elias et al. 1997 ). Similarly, a dominance of C 16 was found in surface sediments of the Nueces Delta, an adjacent area dominated by seagrass and marsh plants (Liu et al. 2013 ). These results, therefore, indicated that biogenic sources, such as algae or seagrass, contributed to the C 16 and other short-chained n -alkanes. The percentage of C 16 decreased greatly from 22% in June 2017 pre-Harvey to 12% in October 2017 after Harvey, and this trend continued to decrease to 5% by March 2018. This pattern suggested a loss of biogenic materials enriched in C 16 , either due to degradation or lateral export. In contrast, the percentages of C 14 , C 18 and C 20 n- alkanes increased in October 2017 relative to June 2017, suggesting temporary input of diatom or bacteria to the surface sediment two months after Hurricane Harvey, possibly due to high nutrient input to the MAE and the enhanced phytoplankton biomass after the hurricane (Elisa et al. 2000; Douglas et al. 2023a ). Similarly, the percentages of long-chained n -alkanes C 29 -C 31 increased, likely as a result of more relative contribution of land vascular plants (Yunker et al. 2011 ) and their resistance to degradation. Therefore, the impact of Harvey on n -alkanes in the surface sediments appears to be long lasting, similar to PAHs, and further research is needed to evaluate the time scale of recovery. Conclusions and implication A hurricane is a unique climate event in which an estuary system might simultaneously experience a storm surge, sediment resuspension, and a decrease in salinity. Here we evaluated the effects of a major hurricane on the sediment geochemistry of a shallow estuary in south Texas using a comprehensive series of parameters, including sediment grain size, bulk organic carbon and stable carbon isotopes, and several organic compound classes that can indicate different biogeochemical processes. The median grain size of the MAE surface sediment significantly increased after Hurricane Harvey, likely because of strong resuspension and further storm surge and currents that transported the finer minerals elsewhere, including offshore. After Harvey, the grain size remained coarser for at least 1.5 years, suggesting that a new baseline may have been established. While the bulk organic carbon and stable carbon isotopes were not affected noticeably by the hurricane, the labile fractions of the organic matter, including THAA and pigments, decreased slightly immediately following the hurricane (1–2 months), but recovered in 7 months, suggesting a quick replenishment of labile organic matter to sediments from the overlying water column or benthic activities. The levels of pheophorbide, a biomarker indicating zooplankton and benthic macrofaunal activities, decreased significantly over the entire MAE right after Harvey, suggesting immediate severe impacts on the activities of zooplankton and benthic macrofaunal species, although they seemed to have fully recovered in 7 months from the biomarker perspective. While bulk organic matter and its labile fractions are continuously replenished by sources from the water column, the impact of Harvey on sedimentary PAHs and n -alkanes, two groups of hydrophobic compounds, resulted in a contrasting pattern. Concentrations of both PAHs and n -alkanes decreased in as many as 5-10-fold after Harvey, likely lost to the water column due to strong sediment resuspension and the enhanced solubility in fresh water, or to the open Gulf of Mexico through the transport of finer minerals with adsorbed compounds. They had not recovered to the pre-Harvey levels after 1.5 years, suggesting that it may take multiple years or decades for these compounds to reconcentrate in surface sediment. It also suggests that hurricanes might play an important role in remobilizing and redistributing estuarine organic contaminates such as PAHs, thus monitoring the water quality of estuaries for these compounds may be necessary after major hurricanes. Overall, this study provided the first systematic data on how a major hurricane impacts the sediment geochemistry in a shallow estuary through strong resuspension, storm surge, and temporary freshening. The impacts on specific organic compound classes differed greatly or were completely decoupled, depending on their sources and association with minerals, thus these chemical classes may be useful to trace different biogeochemical impacts. Declarations Conflict of Interest The authors declare no conflict of interests. Data Availability Statement The original data used in this manuscript can be accessed through BCO-DMO (https://www.bco-dmo.org/dataset/839436). Acknowledgements We would like to thank the Mission Aransas National Estuarine Research Reserve director Jace Tunnel, and research coordinator Dr. Ed Buskey, as well as technicians Kelley Savage and Cammie Hyatt. We also thank Dr. Rong Chen, Dengzhou Gao, Xiangtao Jiang, and Elizabeth Schattle for help with sample processing. Dr. Ryan Hladyniuk helped with CHN and isotope analysis. Funding for this study was provided by Texas Sea Grant (#M1801875 to AH and ZL) and ConTex (joint initiative of The University of Texas System and Mexico’s CONACYT, #2019-63A to ZL), and the National Science Foundation Chemical Oceanography Program (RAPID #1763167 to ZL and AH). References Adams, S. M., M. S. Greeley, J. M. Law, E. J. Noga, and J. T. Zelikoff. 2003. Application of multiple sublethal stress indicators to assess the health of fish in Pamlico Sound following extensive flooding. Estuaries 26(5): 1365–1382. https://doi.org/10.1007/BF02803638 . Ahad, J. M., R. S. Ganeshram, C. L. Bryant, L. M. Cisneros-Dozal, P. L. Ascough, A. E. Fallick, and G. F. Slater. 2011. Sources of n -alkanes in an urbanized estuary: insights from molecular distributions and compound-specific stable and radiocarbon isotopes. Marine Chemistry 126: 239–249. Armstrong, N. E. 1982. Responses of Texas estuaries to freshwater inflows. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4572090","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":315174607,"identity":"b26342b3-047d-47be-acfe-285a2c710677","order_by":0,"name":"Jianhong Xue","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAt0lEQVRIiWNgGAWjYBACxgYg8QHOZSNSC+MMBgMStIAAMw9JWphn5Bg+tm37I2dw/PgDhg9lh4lwWM8ZY+PcNgNjyZ4cA8YZ54jR0t5jJg3UktjPkMPAzNtGjJZmHvPflm0G9W38zx8w/yVKC9AWZsY2gwR+iQQDIIMovxwrluw5Z2w4c8Ybg4M959IJazGckbzxw48yOXmD8+kPH/wosyZCSwMS5wBh9UAgT5SqUTAKRsEoGNkAANbWNwoCmRcTAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0001-7571-4356","institution":"The University of Texas at Austin Marine Science Institute","correspondingAuthor":true,"prefix":"","firstName":"Jianhong","middleName":"","lastName":"Xue","suffix":""},{"id":315174608,"identity":"fbda29a2-dfe1-41ad-8773-1e315bbd00d2","order_by":1,"name":"Zucheng Wang","email":"","orcid":"","institution":"Northeast Normal University","correspondingAuthor":false,"prefix":"","firstName":"Zucheng","middleName":"","lastName":"Wang","suffix":""},{"id":315174609,"identity":"dad0b8b4-01ca-4967-a282-708e0c730a68","order_by":2,"name":"Xianbiao Lin","email":"","orcid":"","institution":"Ocean University of China","correspondingAuthor":false,"prefix":"","firstName":"Xianbiao","middleName":"","lastName":"Lin","suffix":""},{"id":315174610,"identity":"fc893620-c16a-4049-9cbe-c666f35d0b5d","order_by":3,"name":"Kaijun Lu","email":"","orcid":"","institution":"The University of Texas at Austin Marine Science Institute","correspondingAuthor":false,"prefix":"","firstName":"Kaijun","middleName":"","lastName":"Lu","suffix":""},{"id":315174611,"identity":"d8b35f5e-d8a6-4d1f-972b-053c0651f1df","order_by":4,"name":"Sarah Douglas","email":"","orcid":"","institution":"Bigelow Laboratory for Ocean Sciences","correspondingAuthor":false,"prefix":"","firstName":"Sarah","middleName":"","lastName":"Douglas","suffix":""},{"id":315174612,"identity":"be3e90b3-5308-4ed3-9499-1e3fc1427492","order_by":5,"name":"Amber Hardison","email":"","orcid":"","institution":"William \u0026 Mary Virginia Institute of Marine Science","correspondingAuthor":false,"prefix":"","firstName":"Amber","middleName":"","lastName":"Hardison","suffix":""},{"id":315174613,"identity":"daf97eb1-09a4-41d1-86a6-8d31f9f1748b","order_by":6,"name":"Zhanfei Liu","email":"","orcid":"","institution":"The University of Texas at Austin Marine Science Institute","correspondingAuthor":false,"prefix":"","firstName":"Zhanfei","middleName":"","lastName":"Liu","suffix":""}],"badges":[],"createdAt":"2024-06-12 18:52:48","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4572090/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4572090/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s12237-024-01432-w","type":"published","date":"2024-10-29T16:20:17+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":60017714,"identity":"90684ede-a5a9-4ba9-be3d-22302bc00633","added_by":"auto","created_at":"2024-07-10 15:07:23","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":147872,"visible":true,"origin":"","legend":"\u003cp\u003eSampling map and sites in the Mission-Aransas Estuary, south Texas.\u003c/p\u003e","description":"","filename":"Figuresediment1.png","url":"https://assets-eu.researchsquare.com/files/rs-4572090/v1/8f5a18d8bc1ccb4c2cf42a29.png"},{"id":60018540,"identity":"3aa0e010-6904-48e5-a6cd-bcea96f65add","added_by":"auto","created_at":"2024-07-10 15:15:23","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":72402,"visible":true,"origin":"","legend":"\u003cp\u003e(a) The river discharges (daily average, m\u003csup\u003e3\u003c/sup\u003e s\u003csup\u003e-1\u003c/sup\u003e) of the Mission and Aransas rivers in south Texas (data from USGS gages), and (b) the changes of salinity (PSU) and turbidity (NTU) at station Copano Bay West or S01, from March 2017 to March 2019. Meteorological symbols were marked for Hurricane Harvey (August 25, 2017) and heavy precipitation only (June 18, 2018), respectively.\u003c/p\u003e","description":"","filename":"Figuresediment2.png","url":"https://assets-eu.researchsquare.com/files/rs-4572090/v1/9b4a84d4a84ec644ec97f26b.png"},{"id":60017712,"identity":"0f904a5d-2bc1-4c0b-b1f8-5f0c72dfd137","added_by":"auto","created_at":"2024-07-10 15:07:23","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":204662,"visible":true,"origin":"","legend":"\u003cp\u003eMedian grain size (µm) distributions of surface sediments from pre-Harvey to post-Harvey in the Mission-Aransas Estuary.\u003c/p\u003e","description":"","filename":"Figuresediment3.png","url":"https://assets-eu.researchsquare.com/files/rs-4572090/v1/fd7a326b0202db1c0dc0b12d.png"},{"id":60018541,"identity":"b1545025-de9f-479b-9cf2-1489d3975abe","added_by":"auto","created_at":"2024-07-10 15:15:23","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":149034,"visible":true,"origin":"","legend":"\u003cp\u003eAverage ± standard deviation TOC (%), δ\u003csup\u003e 13\u003c/sup\u003eC\u003csub\u003eorg\u003c/sub\u003e (‰), total pigments (µg g\u003csup\u003e-1\u003c/sup\u003e), THAA (µmol g\u003csup\u003e-1\u003c/sup\u003e), total PAHs (ng g\u003csup\u003e-1\u003c/sup\u003e), and \u003cem\u003en\u003c/em\u003e-alkanes (µg g\u003csup\u003e-1\u003c/sup\u003e) at 19 sites from pre- to post-Harvey in the Mission-Aransas Estuary. Among them, TOC and δ\u003csup\u003e13\u003c/sup\u003eC\u003csub\u003eorg\u003c/sub\u003e were not analyzed in August and November 2018. PAHs and \u003cem\u003en\u003c/em\u003e-alkanes were not analyzed for June 2018 and thereafter. Different lowercase letters are used to denote statistical differences (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.05) among different sampling events.\u003c/p\u003e","description":"","filename":"Figuresediment4.png","url":"https://assets-eu.researchsquare.com/files/rs-4572090/v1/bc7777e90b3dbaba5543bcbd.png"},{"id":60017720,"identity":"37de05fd-405f-48a7-81ef-4e2c5c5e45dd","added_by":"auto","created_at":"2024-07-10 15:07:23","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":86212,"visible":true,"origin":"","legend":"\u003cp\u003eTOC% and median grain size (µm) of surface sediments at each sampling site in the Mission-Aransas Estuary. Colors and symbols denote different sampling events.\u003c/p\u003e","description":"","filename":"Figuresediment5.png","url":"https://assets-eu.researchsquare.com/files/rs-4572090/v1/0b7399d70da59ddffc2a762f.png"},{"id":60017717,"identity":"197d85ca-483a-4de9-9306-a0776c819baf","added_by":"auto","created_at":"2024-07-10 15:07:23","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":34488,"visible":true,"origin":"","legend":"\u003cp\u003eThe average ± standard deviation phytoplankton community (weight%) in the Mission-Aransas Estuary surface sediment from June 2017 to March 2019. Different lowercase letters are used to denote statistical differences (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.05) among different sampling events.\u003c/p\u003e","description":"","filename":"Figuresediment6.png","url":"https://assets-eu.researchsquare.com/files/rs-4572090/v1/fb0a8e6a65143873278b4f2c.png"},{"id":60017719,"identity":"ee15ef8a-ee99-4afc-aca9-c8a22ef33330","added_by":"auto","created_at":"2024-07-10 15:07:23","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":72680,"visible":true,"origin":"","legend":"\u003cp\u003eThe average ± standard deviation composition of chloropigments (mole%) in surface sediment from June 2017 to March 2019. Different lowercase letters are used to denote statistical differences (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.05) among different sampling events.\u003c/p\u003e","description":"","filename":"Figuresediment7.png","url":"https://assets-eu.researchsquare.com/files/rs-4572090/v1/90577ce7c2b2fb5440b526c8.png"},{"id":60018542,"identity":"cfedabfc-1c33-4dff-bd31-f661d661b90b","added_by":"auto","created_at":"2024-07-10 15:15:23","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":58798,"visible":true,"origin":"","legend":"\u003cp\u003eThe \u003cem\u003en\u003c/em\u003e-alkanes (C\u003csub\u003e8\u003c/sub\u003e – C\u003csub\u003e33\u003c/sub\u003e) composition (weight%) changes in surface sediment from June 2017 to March 2018.\u003c/p\u003e","description":"","filename":"Figuresediment8.png","url":"https://assets-eu.researchsquare.com/files/rs-4572090/v1/a177f8ee63942c9ae56deb97.png"},{"id":60019291,"identity":"90ad6ba1-7564-426d-a32b-b5728c329b6f","added_by":"auto","created_at":"2024-07-10 15:23:23","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":30879,"visible":true,"origin":"","legend":"\u003cp\u003eThe PAHs concentrations (ng g\u003csup\u003e-1\u003c/sup\u003e) in (a) LMW PAHs (2-3 rings) and (b) HMW PAHs (4-6 rings) in surface sediments from June 2017 to March 2018. Different lowercase letters are used to denote statistical differences (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.05) among different sampling events.\u003c/p\u003e","description":"","filename":"Figuresediment9.png","url":"https://assets-eu.researchsquare.com/files/rs-4572090/v1/43189a81e0e5b543c3eb2b36.png"},{"id":68207149,"identity":"e1402d34-c3e8-4145-82f4-267a6d001d8e","added_by":"auto","created_at":"2024-11-04 16:35:20","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1808807,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4572090/v1/8c1fdee9-1b55-4c8f-bd0a-ecb89974bbc6.pdf"},{"id":60017721,"identity":"8e59b815-5954-48d1-bfb3-87df3d63ad2b","added_by":"auto","created_at":"2024-07-10 15:07:23","extension":"docx","order_by":7,"title":"","display":"","copyAsset":false,"role":"supplement","size":1283707,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementary.docx","url":"https://assets-eu.researchsquare.com/files/rs-4572090/v1/d003d349c8cd18771239ea05.docx"}],"financialInterests":"","formattedTitle":"The impact of a major hurricane on sediment geochemistry of a shallow subtropical estuary through strong resuspension","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe intensity and frequency of tropical cyclones in the North Atlantic basin have increased since the mid-1990s (Webster et al. \u003cspan citationid=\"CR92\" class=\"CitationRef\"\u003e2005\u003c/span\u003e), as illustrated by a rapid rise in the frequency of tropical cyclones striking the Mid-Atlantic and the Gulf of Mexico coasts. In the past 20 years, three 500-year flood events have impacted coastal North Carolina following Hurricanes Floyd (1999), Matthew (2016) and Florence (2018) (Paerl et al. \u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; \u003cspan citationid=\"CR72\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; \u003cspan citationid=\"CR67\" class=\"CitationRef\"\u003e2018a\u003c/span\u003e; \u003cspan citationid=\"CR68\" class=\"CitationRef\"\u003e2019\u003c/span\u003e), and even more severe flooding occurred along the Gulf of Mexico during the catastrophic 2017 Atlantic hurricane season, which included Hurricanes Harvey, Maria, and Irma. Recently, Paerl et al. (\u003cspan citationid=\"CR68\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) examined a 120-year precipitation record for the North Carolina coast, which revealed that 6 out of the 7 \u0026ldquo;wettest\u0026rdquo; events were tropical cyclones that occurred only in the past 20 years. These events severely impact estuarine ecosystems, which play vitally important cultural and economic roles (Emanuel \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Greening et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). Estuarine health has already been greatly influenced by human activities, such as excessive inputs of nutrients that promote harmful algal blooms, hypoxia, and finfish and shellfish kills (Paerl et al. \u003cspan citationid=\"CR71\" class=\"CitationRef\"\u003e1998\u003c/span\u003e; Eby and Crowder \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2002\u003c/span\u003e; Adams et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2003\u003c/span\u003e; Paerl et al. \u003cspan citationid=\"CR72\" class=\"CitationRef\"\u003e2006\u003c/span\u003e, \u003cspan citationid=\"CR69\" class=\"CitationRef\"\u003e2014\u003c/span\u003e, \u003cspan citationid=\"CR70\" class=\"CitationRef\"\u003e2018b\u003c/span\u003e). Therefore, there is a critical need to better understand how estuarine ecosystems would respond under the projected scenarios of climate change and anthropogenic disturbance across geographic and climatic gradients. Particularly, it remains largely unknown how coastal environments are impacted after landfalls of major hurricanes due to the lack of relevant data, as both pre- and post-hurricane data are needed for such evaluation.\u003c/p\u003e \u003cp\u003eHurricane landfalls substantially disturb estuarine and coastal ecosystems, mainly through strong wind, storm surge, heavy precipitation, flooding, and saltwater intrusion (Paerl et al. \u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Hogan et al. \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Depending on the estuarine water flushing time, the return time of the water quality (such as salinity and nutrient concentrations) to pre-storm conditions can vary from days to months (Patrick et al. \u003cspan citationid=\"CR73\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Walker et al. \u003cspan citationid=\"CR88\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). In a short (2\u0026ndash;3 days) residence time system such as Waquoit Bay, a shallow bay near Cape Cod, Massachusetts, the salinity of surface water slightly dropped from 31\u0026ndash;32 to \u0026lt;\u0026thinsp;25 after Hurricane Bob but quickly returned to pre-storm condition in ~\u0026thinsp;7 days (Valiela et al. \u003cspan citationid=\"CR84\" class=\"CitationRef\"\u003e1998\u003c/span\u003e). In a system with longer water residence time such as North Carolina\u0026rsquo;s Neuse River Estuary-Pamlico Sound (2\u0026ndash;6 months, Cooper et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2004\u003c/span\u003e), it could take up to ~\u0026thinsp;8 months for salinity to return to pre-storm condition (Peierls et al. \u003cspan citationid=\"CR74\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). These impacts on water quality might consequently affect phytoplankton communities in estuaries and bays, further affecting primary production and nutrient cycling for a longer period (Paerl et al. \u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Glibert et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2009\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn addition, hurricanes often lead to sediment resuspension, erosion, and subsequent deposition, which alter the concentration, composition, and physicochemical properties of surface sediments in coastal and inner shelf areas (Go\u0026ntilde;i et al. \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Breithaupt et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). This also likely influences the benthic faunal community. For example, immediately following major hurricanes in the Cape Fear Estuary, North Carolina, significant declines in the total benthic community (dominated by opportunistic species) abundance were observed, and the recovery to pre-storm levels took\u0026thinsp;~\u0026thinsp;3 months or longer (Mallin et al. \u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e1999\u003c/span\u003e). Finally, hurricanes may directly transport new contaminants into sediments of coastal areas from local sources through flow caused by heavy rains (Greening et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2006\u003c/span\u003e), resulting in high concentrations of contaminants, such as dichloro-diphenyl-trichloroethane (DDT), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in coastal sediments (Johnson et al. \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Romanok et al. \u003cspan citationid=\"CR77\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). These contaminants could also be redistributed via physical disturbance on sediment in the estuary and coastal regions. After Hurricanes Katrina and Rita in 2005, layers of organic carbon- and mercury-enriched fine grain sediments were redistributed over the northern Gulf of Mexico continental shelf through the Mississippi-Atchafalaya River system (Liu et al. \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Therefore, the landfall of a hurricane may change not only the water quality but also the geochemistry of surface sediments in the impacted estuaries and coastal areas over a longer time scale.\u003c/p\u003e \u003cp\u003eThe impact of hurricanes on sedimentary organic carbon (OC) of estuarine and coastal systems has been widely studied. Go\u0026ntilde;i et al. (\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2006\u003c/span\u003e) reported that a storm layer enriched with fine muds and higher organic content was formed one week after Hurricane Lili (2002) along the inner Louisiana shelf at ~\u0026thinsp;20 m water depth, but not at depths\u0026thinsp;\u0026lt;\u0026thinsp;10 m. They proposed that the elevated OC level in these relatively offshore sediments (0.3\u0026ndash;0.9 wt% pre-hurricane, 0.7\u0026ndash;1.7 wt% post-hurricane) was most likely contributed by the settling and deposition of the finer fraction of the resuspended seabed sediments. However, it was also reported that OC concentrations did not change in the sediments of Lake Pontchartrain and Mississippi Sound two months after Hurricane Katrina in 2005 (Macauley et al. \u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e2010\u003c/span\u003e), or those in the Neuse River Estuary one month following the passage of three hurricanes (Balthis et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). Although the bulk OC content remained relatively constant in these examples, the source or composition of OC in the estuary sediment might have changed after the hurricanes. There have been a limited number of studies that focus on specific compounds classes, such as labile organic carbon (i.e., amino acids and pigments) or petroleum-sourced contaminations (i.e., PAHs and \u003cem\u003en\u003c/em\u003e-alkanes) inside the estuary, which could be used to provide information about changes in OC source in sediments. Amino acids and pigment can be used to indicate the lability or source of organic matter (Liu and Xue \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), while PAHs and \u003cem\u003en\u003c/em\u003e-alkanes indicate the level of environment contaminants that are often of concern after hurricanes.\u003c/p\u003e \u003cp\u003eHurricane Harvey, as a category 4 storm, made landfall\u0026thinsp;~\u0026thinsp;15 km north of the Port Aransas in south Texas on August 25, 2017 (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). It was the first major hurricane to land in the US since 2005, and the strongest in Texas since Carla (1961). Wind gusts in Port Aransas reached 212 km h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (Weather Prediction Center, NOAA), and the eye wall moved directly over the Mission-Aransas Estuary (MAE), a shallow estuarine system isolated from the open Gulf of Mexico by sandbar islands. While the extremely strong winds and powerful storm surge caused by Harvey directly hit the MAE, widespread flash flooding mostly occurred to the northeast of the storm. The Houston metropolitan area received more than 75 cm of precipitation, in contrast with only\u0026thinsp;~\u0026thinsp;10 cm of precipitation in Port Aransas (Source: National Hurricane Center, NOAA) (Blake and Zelinsky \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Therefore, there was clearly a spatial decoupling between the major impacts from wind and flood of Hurricane Harvey on the Texas coast (Patrick et al. \u003cspan citationid=\"CR73\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Hurricane Harvey offered a serendipitous opportunity to evaluate the impacts of a major hurricane on sediment biogeochemistry of an estuarine system.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eGiven the strong winds and storm surge caused by Hurricane Harvey, we hypothesized that the sediment biogeochemistry of the shallow MAE was severely affected and that these effects would last for months or years. Surface sediments from 19 sites across the MAE (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) were initially collected in June 2017 as pre-Harvey baseline data, followed by sampling every two or three months from October 2017 to March 2019 over a period of 1.5 years as post-Harvey observations. A series of geochemical parameters were analyzed in these sediment samples, including sediment grain size, bulk OC and its δ\u003csup\u003e13\u003c/sup\u003eC\u003csub\u003eorg\u003c/sub\u003e, chloro-, and accessory pigments, hydrolyzable amino acids, PAHs, and \u003cem\u003en\u003c/em\u003e-alkanes (C\u003csub\u003e8\u003c/sub\u003e-C\u003csub\u003e33\u003c/sub\u003e). Analyses of PAHs and \u003cem\u003en\u003c/em\u003e-alkanes were completed only through March 2018. These parameters allowed a comprehensive evaluation of the impacts of Harvey on sediment geochemical processes from multiple levels, including bulk perspectives and specific compound classes that may have been impacted differently by the hurricane depending on their sources and association with minerals.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSite Description\u003c/h2\u003e \u003cp\u003eThe Mission Aransas Estuary (MAE) includes the Mission and Aransas rivers, and the Copano, Aransas, and Mesquite Bays, and is bordered by San Jose Island. The MAE is part of the Mission Aransas National Estuarine Research Reserve (MA-NERR), which has continuously monitored physical and water quality parameters at five System-Wide Monitoring Program (SWMP) stations (CW, CE, AB, MB, and SC; Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) since 2007. The MAE has limited exchange with the coastal Gulf of Mexico due to a microtidal range and limited inlet flushing, and the water residence time is estimated to be 1\u0026ndash;3 years on average (Armstrong \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e1982\u003c/span\u003e; Solis and Powell \u003cspan citationid=\"CR81\" class=\"CitationRef\"\u003e1999\u003c/span\u003e). The shallow water depth of Copano and Aransas Bays, with an average of 2 m (Armstrong \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e1987\u003c/span\u003e; Orlando \u003cspan citationid=\"CR64\" class=\"CitationRef\"\u003e1993\u003c/span\u003e), results in strong benthic-pelagic interactions, such as nutrient regeneration and the influence of the benthos on the water column. The shallow water depth also makes it ideal to evaluate the effects of winds and storms on estuarine sediment geochemistry.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eSample Collection\u003c/h2\u003e \u003cp\u003eSediments were collected using acrylic core tubes (8.2 cm outer diameter, 7.6 cm inner diameter, and 30.5 cm in length) from 19 sites (S01-S20; collection at S14 unsuccessful because S14 was inside the ship channel, which turned out too deep for hand core to reach the bottom) in the MAE (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). At each site, three cores were collected, and the surface layer (0\u0026ndash;5 cm) of each core was sectioned on deck. The three surface sections were combined and homogenized as a composite sample and stored in a cooler on ice. The samples were transported back to the lab within the same day and kept at -80\u0026deg;C in a freezer until analysis. The pre-Harvey samples were collected on June 8\u0026ndash;9, 2017, two months before Hurricane Harvey made landfall; and the post-Harvey samples were collected on October 17\u0026ndash;18, 2017 (53 days after landfall). In 2018, samples were collected on January 29\u0026ndash;30, March 29-April 8, June 21\u0026ndash;22, August 30\u0026ndash;31, and November 14\u0026ndash;15. A final sampling was taken on March 6\u0026ndash;7, 2019, 1.5 years after the hurricane. Additional two layers (5\u0026ndash;10 and 10\u0026ndash;15 cm) of sediments were collected at site S09 in June 2017 and October 2017 only. For each sediment sample collection, corresponding surface (~\u0026thinsp;0.1 m depth) water for inorganic nutrient analysis was also collected with acid-washed opaque polyethylene bottles, placed on ice and transported to the lab within the same day. Water samples were filtered through 0.7 \u0026micro;m pre-combusted glass fiber filters (GF/F) and stored frozen (-20\u0026deg;C) until analysis. In addition, water quality data, including temperature, salinity, and turbidity, have been continuously measured every 15 min onsite at the five SWMP stations since 2007, and the data are ​​also available online (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://cdmo.baruch.sc.edu\u003c/span\u003e\u003cspan address=\"http://cdmo.baruch.sc.edu\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e).\u003c/span\u003e Daily river discharge data for Mission River (gage 08189500) and Aransas River (gage 08189700) during 2017\u0026ndash;2019 were obtained from the United States Geological Survey (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://waterdata.usgs.gov/nwis\u003c/span\u003e\u003cspan address=\"https://waterdata.usgs.gov/nwis\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e).\u003c/span\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eNutrient analyses\u003c/h2\u003e \u003cp\u003eDissolved inorganic nitrogen (nitrate (NO\u003csub\u003e3\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e), nitrite (NO\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e), ammonium (NH\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e)) concentrations were determined using a SmartChem Chemistry Analyzer with standard EPA colorimetric methods (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://wrrc.unh.edu/analytical-instrumentation\u003c/span\u003e\u003cspan address=\"https://wrrc.unh.edu/analytical-instrumentation\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eMineral grain size\u003c/h2\u003e \u003cp\u003eThe grain size of surface sediment was measured by a laser particle size analyzer (S3500; Microtrac Inc., Montgomeryville, PA, USA) based on a method modified from Gee and Or (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2002\u003c/span\u003e). Briefly, ~ 0.2 g of unground sediment sample was mixed thoroughly with 15 mL of H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e (1:2 v:v, H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e:H\u003csub\u003e2\u003c/sub\u003eO) for 5 min to remove organic matter. Ten mL HCl (1:2, HCl:H\u003csub\u003e2\u003c/sub\u003eO) was then added to the bottle, and the bottle was incubated in a thermostat water bath at 40\u0026deg;C for 24 h to remove calcareous minerals. After incubation, 10 mL Nanopure water was added, and the bottle stayed still until the sediment had visually settled to remove Cl ions. The overlying water was gently removed by pipetting without disturbing the sediment. Another 10 mL Nanopure water was added to the bottle and the overlying water was removed by repeating the same procedure. Afterward, 10 mL (NaPO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e6\u003c/sub\u003e solution (0.5 mol L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) was added to the bottle. The whole bottle was shaken for 15 min in an ultrasonic shaker before analysis. The detectable grain size range for this analyzer was from 0.02 to 2000 \u0026micro;m.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eOrganic carbon, nitrogen, and the carbon stable isotope δ\u003csup\u003e13\u003c/sup\u003eC\u003csub\u003eorg\u003c/sub\u003e\u003c/h2\u003e \u003cp\u003eTotal organic carbon (TOC), total nitrogen (TN), and the stable carbon isotope δ\u003csup\u003e13\u003c/sup\u003eC\u003csub\u003e\u003cb\u003eorg\u003c/b\u003e\u003c/sub\u003e in surface sediments were measured by a CHN elemental analyzer coupled with a Thermo Delta V Plus isotope ratio mass spectrometer. Samples were fumigated with concentrated hydrochloric acid in a sealed container for 24 h to remove carbonates prior to analysis (Hedges and Stern \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e1984\u003c/span\u003e). Precision for C and N was within 5% and for δ\u003csup\u003e13\u003c/sup\u003eC\u003csub\u003e\u003cb\u003eorg\u003c/b\u003e\u003c/sub\u003e was within 0.2\u0026permil;.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003ePigment analysis\u003c/h2\u003e \u003cp\u003eBoth chloro- and accessory pigments in surface sediments were analyzed chromatographically. Approximately 2 g of frozen sediment was transferred into a 15 mL polypropylene centrifuge tube, and 3 mL acetone was added for pigment extraction (Sun et al. \u003cspan citationid=\"CR82\" class=\"CitationRef\"\u003e1991\u003c/span\u003e). The mixture was sonicated for 15 min, and then centrifuged for another 10 min. The acetone extract was siphoned with a glass pipette and filtered with a syringe filter (0.2 \u0026micro;m Nylon). The remaining sediment in the centrifuge tube was extracted again by the same procedure, and the two extracts were combined. Pigments in the extract were quantified using high performance liquid chromatography (HPLC) according to Liu and Xue (\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Briefly, five specific chloropigments, including chlorophyll \u003cem\u003ea\u003c/em\u003e (Chl \u003cem\u003ea\u003c/em\u003e), chlorophyll b (Chl \u003cem\u003eb\u003c/em\u003e), divinyl chlorophyll \u003cem\u003ea\u003c/em\u003e (DVChl \u003cem\u003ea\u003c/em\u003e), pheophorbide \u003cem\u003ea\u003c/em\u003e (Phide) and pheophytin-\u003cem\u003ea\u003c/em\u003e (Phytin) were identified using a fluorescence detector attached to the HPLC. Seven carotenoids, including peridinin (Peri), 19\u0026rsquo;-butanoyloxyfucoxanthin (19-but), fucoxanthin (Fuco), prasinoxanthin (Pras), 19\u0026rsquo;-hexanoyloxyfucoxanthin (19-hex), alloxanthin (Allo), and zeaxanthin (Zea) were also quantified using a photodiode array detector attached to the HPLC. The water contents were considered in each sediment sample in order to obtain pigments concentrations on a dry sediment basis. The carotenoids were used to construct the phytoplankton community based on established algorithms (Letelier et al. \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e1993\u003c/span\u003e; Lambert et al. \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e1999\u003c/span\u003e; Qian et al. \u003cspan citationid=\"CR75\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). Duplicate analyses of the same extract generally agreed within 20%.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eTotal hydrolyzable amino acids (THAA)\u003c/h2\u003e \u003cp\u003eApproximately 0.5 g of freeze-dried sediment was transferred into glass tubes containing 5 mL 6 N HCl, sealed under nitrogen gas, and then hydrolyzed at 110\u0026deg;C for 20 h. The hydrolyzed solutions were dried with nitrogen gas and replaced with deionized (DI) water, and then the hydrolyzed amino acids were analyzed using HPLC after being derivatized by \u003cem\u003eo\u003c/em\u003e-phthaldialdehyde following Liu and Xue (\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Sixteen amino acids were quantified through comparison with an authentic standard mixture (Sigma), which includes aspartic acid (ASP), glutamic acid (GLU), histidine (HIS), serine (SER), arginine (ARG), glycine (GLY), threonine (THR), β-alanine (BALA), alanine (ALA), tyrosine (TYR), γ-aminobutyric acid (GABA), methionine (MET), valine (VAL), phenylalanine (PHE), isoleucine (ILE), and leucine (LEU). Duplicate analyses of amino acids from the same extract generally agreed within 10%.\u003c/p\u003e \u003cp\u003e \u003cb\u003ePolycyclic aromatic hydrocarbons (PAHs) and\u003c/b\u003e \u003cb\u003en\u003c/b\u003e\u003cb\u003e-alkanes\u003c/b\u003e\u003c/p\u003e \u003cp\u003eSurface sediment 16 US EPA priority PAHs and \u003cem\u003en\u003c/em\u003e-alkanes in the range of C\u003csub\u003e8\u003c/sub\u003e-C\u003csub\u003e33\u003c/sub\u003e were analyzed. PAHs with 2 benzene rings (naphthalene, acenaphthene, acenaphthylene, and fluorene) and 3 rings (phenanthrene and anthracene) were defined as low molecular weight (LMW), and those with 4\u0026ndash;6 rings including fluoranthene, pyrene, benzo[a]anthracene, and chrysenebenzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3]pyrene, dibenzo[a,h]anthracene, and benzo[g,h,i]perylene were defined as high molecular weight (HMW).\u003c/p\u003e \u003cp\u003eBriefly, ground freeze-dried sediments (4 g) mixed with surrogate standards (phenanthrene-d10 and hexadecane-d34) were extracted by accelerated solvent extraction (ASE-350) using a mixture of acetone and dichloromethane (1:1, v/v) (Wang et al. \u003cspan citationid=\"CR91\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). The extraction cells were heated to 100\u0026deg;C until the pressure of 10 MPa was reached. The static time was 10 min, the flush volume was 60%, and the purge time was 90 s. The final volume of the extract was ca. 30\u0026ndash;40 mL, which was further concentrated with hexane to about 1 mL by a rotary evaporator. The concentrated extract was purified with a chromatographic column, which was packed with activated silica (6 g, 100\u0026ndash;200 mesh, activated at 160\u0026deg;C for 16 h) and topped with 1 g of anhydrous sodium sulfate (baked at 450\u0026deg;C for 4 h). After the column was conditioned with 20 mL hexane, the extract was added to the top of the column and eluted with 12 mL hexane, which was collected for \u003cem\u003en\u003c/em\u003e-alkane analysis. The column was further eluted with 15 mL dichloromethane/hexane (1:1, v/v), which was collected for PAH analysis. The eluents were reduced to 1 mL by a rotary evaporator and transferred to a 2 mL glass vial, preserved in a freezer at -20\u0026deg;C until gas chromatography\u0026ndash;mass spectrometry (GC-MS) analysis.\u003c/p\u003e \u003cp\u003eA GC-MS with a Rxi-5Sil column (30 m \u0026times; 0.25 mm; 0.25 \u0026micro;m film thickness) was used to measure the 16 PAHs and \u003cem\u003en\u003c/em\u003e-alkanes. The scanned mass over charge (m/z) ratios ranged from 127 to 279 for PAHs, and 57 and 71 for \u003cem\u003en\u003c/em\u003e-alkanes. For PAH analysis the oven temperature was held at 40\u0026deg;C for 4 min, increased to 280\u0026deg;C at a rate of 10\u0026deg;C min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and held for 4 min, then increased to 300\u0026deg;C at a rate of 10\u0026deg;C min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and held for 5 min. For \u003cem\u003en\u003c/em\u003e-alkanes the oven temperature was held at 70\u0026deg;C for 4 min, and increased to 290\u0026deg;C at a rate of 10\u0026deg;C min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, then held for 40 min. The injector and detector temperatures were both 250\u0026deg;C. The injection volume was 1 \u0026micro;L in a splitless mode. The recovery rates of the surrogates ranged from 60\u0026ndash;110%. Negligible PAHs were detected in our method blank. The detection limit for PAHs and \u003cem\u003en\u003c/em\u003e-alkanes were 0.01 ppm and 0.1 ppm, respectively. An external standard was used to calculate the concentrations of the PAHs and \u003cem\u003en\u003c/em\u003e-alkanes.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eA two-way ANOVA followed by the Tukey-Kramer test was performed for each variable, seeking statistical significance among sampling events. A Student\u0026rsquo;s t\u003cem\u003e-\u003c/em\u003etest was performed to determine statistical significance among the sampling sites. Principal component analysis (PCA) was applied on composition data of THAA using MATLAB (Xue et al. \u003cspan citationid=\"CR94\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). All statistical analyses were performed with MATLAB R2019a.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eWater quality changes in the MAE after Hurricane Harvey\u003c/h2\u003e \u003cp\u003eThe landfall of Harvey on San Jose Island and its passage through the MAE caused strong winds and a major storm surge in this estuarine system (Blake and Zelinsky \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). The heavy precipitation in the southeastern Texas coastal area enhanced the discharge of the Mission and Aransas rivers for about 2 weeks after Harvey (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea). The increased freshwater inflow led to a drastic decrease in salinity in the MAE after Harvey. In Copano Bay (station CW, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb), salinity dropped rapidly from 22.9 on August 24 to 3.3 on September 4, and it took\u0026thinsp;~\u0026thinsp;8 months to slowly return to 22.9, the pre-Harvey level. In contrast, the daily turbidity average at this station increased instantly from 20 nephelometric turbidity units (NTU) on August 24 to 775 on August 26, but decreased rapidly back to \u0026lt;\u0026thinsp;20 within 1 week on August 30 (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb). This suggests that particles were abruptly suspended in the water column, likely caused by storm surge, waves, and wind, and then decreased to background levels within 1 week (Lou et al. \u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Most of the suspended particles either quickly settled back into the sediment or were transported laterally via storm surge after the hurricane.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eConcentrations of dissolved nitrates (NO\u003csub\u003e3\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e plus NO\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e) in surface water at these 19 sites were low (0.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.3 \u0026micro;M) in both Copano and Aransas bays before Harvey, but increased to 1.9\u0026thinsp;\u0026plusmn;\u0026thinsp;3.1 \u0026micro;M in October 2017, likely due to the increased river discharge after Harvey (Wei et al. \u003cspan citationid=\"CR93\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). The nitrates level increased again in June 2018 due to enhanced river discharge by heavy precipitation (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea), with 3.1\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1 \u0026micro;M on average (4.7\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2 \u0026micro;M in Copano Bay and 1.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5 \u0026micro;M in Aransas Bay). The concentration of NH\u003csub\u003e4\u003c/sub\u003e\u003csup\u003e+\u003c/sup\u003e was 1.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7 \u0026micro;M before Harvey, slightly dropped to 0.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6 \u0026micro;M after Harvey in October 2017, but increased back to 3.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4 \u0026micro;M in June 2018.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eMineral grain size of surface sediments\u003c/h2\u003e \u003cp\u003eThe sediment was categorized into three groups based on grain size: sands (63-2000 \u0026micro;m), silts (4\u0026ndash;63 \u0026micro;m), and clays (0.02-4 \u0026micro;m). The MAE sediment was dominated by sands and silts, as clays generally accounted for only\u0026thinsp;~\u0026thinsp;2% of the total for both pre- (June 2017) and post-Harvey (every two or three months from October 2017 to March 2019). Thus, only sand and silt fractions are reported here (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The pre-Harvey sediments were dominated by silts (70\u0026thinsp;\u0026plusmn;\u0026thinsp;12%), except for sites S06 and S16 (both are in bay-margin areas), which were dominated by sands, accounting for 94% and 72% of the total, respectively. In October 2017 post-Harvey, these two sites were still dominated by sands, with a percentage of 81% and 86%, respectively. Slight variations on the silt percentages (67\u0026thinsp;\u0026plusmn;\u0026thinsp;13%) were observed for all other sites, except that site S13 was completely changed from silts (67%) into sands (99%). In March 2018, another site (S20) was also observed turning completely into sand (100%). By March 2019, 1.5 years post-Harvey, the number of sand-dominated sites (i.e., sand% \u0026ge; 65%) increased from two (i.e., S06 and S16) to four (i.e., with the addition of S13 and S20, sand 66% and 67% respectively). Silt fractions also slightly decreased (56\u0026thinsp;\u0026plusmn;\u0026thinsp;9% silt) at the other 15 sites.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSurface sediment fractions (%) for sand (63\u0026thinsp;~\u0026thinsp;2000 \u0026micro;m) and silt (4\u0026ndash;63\u0026micro;m) at each sample site during pre-Harvey (June 2017) and post-Harvey (October 2017 to March 2019) in the Mission-Aransas Estuary in south Texas.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"17\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c14\" colnum=\"14\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c15\" colnum=\"15\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c16\" colnum=\"16\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c17\" colnum=\"17\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eStations\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"16\" nameend=\"c17\" namest=\"c2\"\u003e \u003cp\u003eSediment fractions (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"8\" nameend=\"c9\" namest=\"c2\"\u003e \u003cp\u003eSand (63-2000 \u0026micro;m)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"8\" nameend=\"c17\" namest=\"c10\"\u003e \u003cp\u003eSilt (4\u0026ndash;63 \u0026micro;m)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eJun-17\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOct-17\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eJan-18\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMar-18\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eJun-18\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eAug-18\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNov-18\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eMar-19\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eJun-17\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003eOct-17\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e \u003cp\u003eJan-18\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c13\"\u003e \u003cp\u003eMar-18\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c14\"\u003e \u003cp\u003eJun-18\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c15\"\u003e \u003cp\u003eAug-18\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c16\"\u003e \u003cp\u003eNov-18\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c17\"\u003e \u003cp\u003eMar-19\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS01\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS02\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e61\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS03\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e58\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS04\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS05\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e69\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS06\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS07\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS08\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS09\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e63\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS10\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e57\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS11\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS12\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e56\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS13\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e34\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS15\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS16\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS17\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS18\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e46\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS19\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eS20\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c15\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c16\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c17\"\u003e \u003cp\u003e33\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eMedian grain size, the midpoint of sediment size distribution by weight, is another way to quantify the size change of sediment particles. From June 2017 to March 2019, the median grain size sharply increased at site S13, from 60 \u0026micro;m in June 2017 to 134 \u0026micro;m in October 2017, but then decreased to 101 \u0026micro;m in March 2019 (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). A similar trend was observed at site S19, which had a median grain size of 30 \u0026micro;m in June 2017, increased to 88 \u0026micro;m in October 2017, and then decreased to 54 \u0026micro;m in March 2019. A sharp increase in median grain size was also observed at site S20 in March 2018 (164 \u0026micro;m), which then later decreased to 97 \u0026micro;m in March 2019. By March 2019, the four sand-dominated sites (i.e., S06, S13, S16, and S20) had a notably higher median grain size (119\u0026thinsp;\u0026plusmn;\u0026thinsp;28 \u0026micro;m) than the other 15 non-sand dominant sites (70\u0026thinsp;\u0026plusmn;\u0026thinsp;15 \u0026micro;m) (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0001). Overall, even though the average median grain size did not significantly increase over the 19 sites between June 2017 (57\u0026thinsp;\u0026plusmn;\u0026thinsp;31\u0026micro;m) and October 2017 (66\u0026thinsp;\u0026plusmn;\u0026thinsp;35\u0026micro;m), sediment became significantly coarser in January, June, August of 2018 and March 2019 (i.e., 79\u0026thinsp;\u0026plusmn;\u0026thinsp;32\u0026micro;m, 83\u0026thinsp;\u0026plusmn;\u0026thinsp;37\u0026micro;m, 82\u0026thinsp;\u0026plusmn;\u0026thinsp;38\u0026micro;m, and 80\u0026thinsp;\u0026plusmn;\u0026thinsp;27 \u0026micro;m, respectively), compared with that in pre-Harvey (57\u0026thinsp;\u0026plusmn;\u0026thinsp;31 \u0026micro;m) (Fig. \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Almost 1.5 years after Harvey, the median grain size of the surface sediment remained significantly different from what it was before Harvey.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eConcentrations of total organic carbon (TOC%) and δ\u003csup\u003e13\u003c/sup\u003eC\u003csub\u003eorg\u003c/sub\u003e\u003c/h2\u003e \u003cp\u003eThe average TOC% in surface sediments at the 19 sites ranged from 0.7\u0026ndash;0.9%, and there was no significant difference between pre- and post-Harvey samples (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.2, Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea). At specific sites, however, there were large variations among different sampling periods. For example, at S05, TOC% was 0.43% in June 2017, doubled in March 2018 (1.2%), and then dropped to 0.75% in March 2019. At S01, TOC% was high (1.2%) in June 2017, then dropped to 0.79% in March 2018 and 0.50% in March 2019. Moreover, large variations of TOC% were observed spatially even in the same month, and the TOC% values were negatively correlated with the median grain size (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e, p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), indicating that TOC was associated mainly with finer minerals (i.e., smaller grain size). Consistently, the TOC% at four sand-dominated sites (i.e., S06, S13, S16, and S20, all with an average sand fraction\u0026thinsp;\u0026gt;\u0026thinsp;60%, Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) was 0.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18%, significantly lower than those of the remaining 15 sites (0.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.30%) (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). However, there were no significant changes of TOC% between pre-Harvey and post-Harvey samples for either group (i.e., the four sands-dominated sites or the remaining 15 sites).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe δ\u003csup\u003e13\u003c/sup\u003eC\u003csub\u003eorg\u003c/sub\u003e value was \u0026minus;\u0026thinsp;20.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0\u0026permil; pre-Harvey in June 2017, became more depleted in October 2017 (-21.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2\u0026permil;) after Harvey (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.02), but then returned to pre-Harvey levels when samples were further collected in January 2018, March 2018, and March 2019 (-19.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9, -20.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7, and \u0026minus;\u0026thinsp;19.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u0026permil;) (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb). Specifically, the depletion in δ\u003csup\u003e13\u003c/sup\u003eC\u003csub\u003eorg\u003c/sub\u003e in October 2017 was driven mostly by samples at sites S05 (-23.0\u0026permil;), S06 (-24.1\u0026permil;), S15 (-23.0\u0026permil;), and S16 (-23.3\u0026permil;). In June 2018, the δ\u003csup\u003e13\u003c/sup\u003eC\u003csub\u003eorg\u003c/sub\u003e value (19.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2\u0026permil;) became relatively enriched among all the sampling events.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eTotal pigments and phytoplankton community\u003c/h2\u003e \u003cp\u003eThe averaged total pigments in surface sediments ranged from 1.6\u0026ndash;4.6 \u0026micro;g g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, with lowest values in January 2018 and highest values in March 2019 (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec). Among the 19 sites, higher pigment concentrations (\u0026gt;\u0026thinsp;3.0 \u0026micro;g g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) occurred in eastern Copano Bay (S03, S04, S05, S07, S08, and S09) and upper Aransas Bay (S11, S17, and S19). Lower pigment concentrations (\u0026lt;\u0026thinsp;1.2 \u0026micro;g g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) were observed in sand-dominated sites (S06, S13, S16, and S20). For all samples combined, ~\u0026thinsp;70% of the total pigments were chloropigments, with the remainder as carotenoids. According to accessory pigment algorithms developed for this region (Reyna et al. \u003cspan citationid=\"CR76\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Douglas et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2023a\u003c/span\u003e), cyanobacteria, diatoms, and cryptophytes were the major algal groups, contributing about 90% of the total community (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). However, the abundance of cyanobacteria was significantly higher in October 2017 (72\u0026thinsp;\u0026plusmn;\u0026thinsp;10%) than any other sampling period (second highest 57\u0026thinsp;\u0026plusmn;\u0026thinsp;9% in March 2019, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05), indicating that cyanobacteria may have become the dominant algal group in the water column immediately following Harvey, but then declined over time. By March 2019, the abundance of cyanobacteria (57\u0026thinsp;\u0026plusmn;\u0026thinsp;9%) was still significantly higher than it was pre-Harvey (45\u0026thinsp;\u0026plusmn;\u0026thinsp;13%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). In contrast, the abundance of diatoms was significantly lower in October 2017 (14\u0026thinsp;\u0026plusmn;\u0026thinsp;12%), and remained low through June 2018 (highest 15\u0026thinsp;\u0026plusmn;\u0026thinsp;18% in June 2018), compared to the pre-Harvey level in June 2017 (27\u0026thinsp;\u0026plusmn;\u0026thinsp;15%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eApproximately 60% (in molar units) of the chloropigments were Chl \u003cem\u003ea\u003c/em\u003e, 10% pheophorbide, and the other 30% pheophytin (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e). The average composition of the chloropigments remained relatively constant over time, but there were significant changes in the proportion of pheophorbide right after Harvey. The concentration of pheophorbide dropped roughly 7-fold from 0.28 \u0026micro;g g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in June 2017 to 0.038 \u0026micro;g g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in October 2017 (Fig. S2b), corresponding to a drop from 15\u0026ndash;4% in composition. The level of pheophorbide in October 2017 was the lowest among all the sampling periods (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e). However, the abundance of pheophorbide recovered quickly in January 2018 (12%) and March 2018 (15%), and the concentration recovered in March 2018 (0.20 \u0026micro;g g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e; Fig. S2b), seven months after Harvey.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eTotal hydrolyzed amino acids (THAAs)\u003c/h2\u003e \u003cp\u003eThe concentrations of THAAs at the 19 sites dropped greatly from 5.1 \u0026micro;mol g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in June 2017 to 2.7 \u0026micro;mol g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in October 2017 after Harvey, then slowly increased, peaking in June 2018 (5.1 \u0026micro;mol g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), which was comparable to that of June 2017 (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ed). Throughout the sampling period, THAA concentration at sand-dominated sites (S06, S13, S16, and S20) was 3.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5 \u0026micro;mol g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, significantly lower than those at the other 15 sites (4.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9 \u0026micro;mol g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.002). Overall, THAA-C contributed 3\u0026thinsp;\u0026plusmn;\u0026thinsp;2% of organic carbon in surface sediments, but it contributed more at the sand-dominated sites (11\u0026thinsp;\u0026plusmn;\u0026thinsp;8%).\u003c/p\u003e \u003cp\u003eASP, GLY, and ALA were the most abundant amino acids at all sites, and they accounted for 40% of the total amino acids (Fig. S3). Principal component analysis (PCA) was performed on the THAA compositional data, with the first two PCs shown in Figure S4. Most of the pre-Harvey samples (June 2017) were enriched in SER, GLY and THR, indicative of sources from diatoms (Sheridan et al. \u003cspan citationid=\"CR78\" class=\"CitationRef\"\u003e2002\u003c/span\u003e), while the post-Harvey (i.e., October 2017) samples were located on the opposite direction along the first PC, enriched with PHE, HIS and ILE. This suggests a sudden composition shift immediately after Harvey. However, the THAA composition in June 2018 was highly similar to those reported pre-Harvey (June 2017), suggesting that THAAs in sediments had fully recovered one year after Harvey.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003ePolycyclic aromatic hydrocarbons (PAHs)\u003c/h2\u003e \u003cp\u003eThe PAHs were only analyzed in June 2017 (pre-Harvey) through March 2018 (post-Harvey) (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ee). The concentrations of PAHs in surface sediment pre-Harvey were 436\u0026thinsp;\u0026plusmn;\u0026thinsp;303 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, with large variations among the 19 sites. These concentrations were correlated with \u003cem\u003en\u003c/em\u003e-alkanes (r\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.61, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0001; Fig. S5a), and TOC% (r\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.36, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.007; Fig. S5b). Fine particles (median grain size\u0026thinsp;\u0026lt;\u0026thinsp;63 \u0026micro;m) tended to have higher levels PAHs except at site S07, which was unusually high (1401 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) (Fig. S5c). The average concentrations of PAHs decreased 4-fold at the 19 sampling sites following Harvey in October 2017 (103\u0026thinsp;\u0026plusmn;\u0026thinsp;66 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), and further decreased 2-fold in January 2018 (50\u0026thinsp;\u0026plusmn;\u0026thinsp;33 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ee). The level of PAHs stabilized in March 2018 (66\u0026thinsp;\u0026plusmn;\u0026thinsp;40 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). The magnitude of change however differed greatly between HMW PAHs and LMW PAHs. The concentrations of HMW PAHs did not change much after Hurricane Harvey, whereas more than 90% of the decrease in October 2017 was attributed to the loss of LMW PAHs (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e9\u003c/span\u003e). But neither LMW- nor HMW PAHs changed after January 2018. For the two additional layers (5\u0026ndash;10 and 10\u0026ndash;15 cm) of the sediment collected in site S09, PAHs were also decreased greatly following Harvey in October 2017 (Fig. S6). Consistently, 90% of the decrease was due to the loss of LMW PAHs.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eTotal\u003c/b\u003e \u003cb\u003en\u003c/b\u003e\u003cb\u003e-alkanes\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThe \u003cem\u003en\u003c/em\u003e-alkanes were analyzed from June 2017 through March 2018 (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ef). The concentrations of total \u003cem\u003en\u003c/em\u003e-alkanes in surface sediments were 12\u0026thinsp;\u0026plusmn;\u0026thinsp;8.3 \u0026micro;g g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e pre-Harvey, with large variations among the 19 sites. Like PAHs, high \u003cem\u003en\u003c/em\u003e-alkanes concentrations also occurred in sediments with high TOC% (Fig. S5d) and low median grain size (Fig. S5e), which is consistent with earlier findings that TOC and specific organic compound classes tend to be concentrated in finer silt and clay fractions in sediments (Mayer \u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e1994\u003c/span\u003e; Liu et al. \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). The concentrations of \u003cem\u003en\u003c/em\u003e-alkanes decreased three-fold at all 19 sampling sites following Harvey in October 2017 (4.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.9 \u0026micro;g g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), and further decreased two-fold in January 2018 (2.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7 \u0026micro;g g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). The concentrations of \u003cem\u003en\u003c/em\u003e-alkanes in March 2018 (2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.7 \u0026micro;g g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) were similar to those in January 2018, indicating that \u003cem\u003en\u003c/em\u003e-alkanes in surface sediment stabilized five months after the disturbance by Harvey.\u003c/p\u003e \u003cp\u003eThere was a slight difference in the \u003cem\u003en\u003c/em\u003e-alkanes composition throughout the sampling periods (Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e8\u003c/span\u003e). Before Harvey in June 2017, \u003cem\u003en\u003c/em\u003e-alkanes exhibited a unimodal distribution pattern, centering at C\u003csub\u003e12\u003c/sub\u003e-C\u003csub\u003e21\u003c/sub\u003e as the predominant compounds, with C\u003csub\u003e16\u003c/sub\u003e as the most abundant. Moreover, the short-chained \u003cem\u003en\u003c/em\u003e-alkanes were dominated by even-numbered compounds, yet the long-chained \u003cem\u003en\u003c/em\u003e-alkanes were dominated by odd-numbered compounds. After Harvey, in October 2017, total \u003cem\u003en\u003c/em\u003e-alkanes showed a bimodal distribution pattern centered at C\u003csub\u003e14\u003c/sub\u003e - C\u003csub\u003e21\u003c/sub\u003e and C\u003csub\u003e25\u003c/sub\u003e - C\u003csub\u003e31,\u003c/sub\u003e maintaining the even and odd predominance, respectively. There was a reduction in C\u003csub\u003e16\u003c/sub\u003e levels, countered by increased percentages of both the short-chain even hydrocarbons (C\u003csub\u003e14\u003c/sub\u003e, C\u003csub\u003e18\u003c/sub\u003e, and C\u003csub\u003e20\u003c/sub\u003e), and the long-chain odd hydrocarbons (C\u003csub\u003e27\u003c/sub\u003e, C\u003csub\u003e29\u003c/sub\u003e, and C\u003csub\u003e31\u003c/sub\u003e). In January and March of 2018, although bimodal distribution remained, the \u003cem\u003en\u003c/em\u003e-alkane C\u003csub\u003e16\u003c/sub\u003e was no longer the dominant hydrocarbon. The short-chain even hydrocarbons (C\u003csub\u003e18\u003c/sub\u003e and C\u003csub\u003e20\u003c/sub\u003e) also decreased, alongside an increase in long-chain odd hydrocarbons (C\u003csub\u003e29\u003c/sub\u003e and C\u003csub\u003e31\u003c/sub\u003e). By March 2018, C\u003csub\u003e31\u003c/sub\u003e was the most abundant \u003cem\u003en\u003c/em\u003e-alkane, and the short-chain \u003cem\u003en\u003c/em\u003e-alkanes were no longer dominated by even ones.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cdiv id=\"Sec19\" class=\"Section2\"\u003e \u003ch2\u003eSurface sediment grain size generally increased across the MAE after Harvey\u003c/h2\u003e \u003cp\u003eHurricane Harvey\u0026rsquo;s landfall on San Jose Island and passage over the MAE led to an unprecedentedly strong storm surges in the affected region. While heavy precipitation enhanced terrigenous matter input from the rivers, storm surge from the seaward direction greatly impacted the MAE (Blake \u0026amp; Zelinsky \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Water turbidity caused by the storm surge reached as high as 1300 NTU in Copano Bay West on August 26, 2017, the highest recorded since this MA-NERR SWMP station was established in 2007, though it quickly decreased to 100 NTU by August 30, 2017. The dramatically increased water column turbidity, associated with high concentrations of particles including minerals, indicated strong sediment resuspension, and further transport and/or redistribution of particles in this area. For example, a strong current outflow as high as 2.0 m s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e along the Lydia Ann Channel (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), accompanied by erosion along the bayside shoreline of San Jose Island, were observed during Hurricane Harvey (Goff et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). After surface sediments in the impacted area were resuspended, the settling and transport of finer and coarser particles may have been subject to different transport modes, causing some dynamic sorting to take place depending on particle size and physical energy (Dyer \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e1995\u003c/span\u003e). Smaller-sized particles were more likely transported to the coastal Gulf of Mexico with the strong outflow via the Lydia Ann Channel, while the relatively large-sized particles likely resettled in the local estuarine surface sediments. As a result, the lower side of the Aransas Bay, including sites S12, S13, S15 and S16, immediately became coarser following Harvey in October 2017 (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Note that both the Mission and Aransas rivers experienced a large discharge event again on June 19\u0026ndash;20, 2018 (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea), and the lower side of the Aransas Bay also became coarser correspondingly, though turbidity level were not notably different after that event. This indicates that, in the MAE, river flooding events alone may also likely to produce discharges strong enough to carry the fine particles away from the estuary, as compared with the extreme wind-driven waves and strong storm surges brought by Harvey.\u003c/p\u003e \u003cp\u003eIn Galveston Bay, located\u0026thinsp;~\u0026thinsp;250 km northeast of the MAE, following Harvey, as much as 48 cm of coastal erosion followed by 22 cm of new sediment deposition were observed inside the San Jacinto Estuary, equivalent to about 18 years of average sediment loads delivered into Galveston Bay following the storm (Du et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Li et al. (\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2015\u003c/span\u003e) reported that on the inner shelf of the Eastern China Sea during Typhoon Morakot in 2009, large amounts of fine particles in seafloor sediments were resuspended into the water column, resulting in much coarser sediments following the typhoon. Other studies have also documented that major hurricane affected coastal landscapes, especially salt marsh sediments, by eroding, redistributing, and depositing sediments via waves and storm surges (Bera et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). From the time-series observations of this study, the median grain size of the MAE surface sediment remained coarser 1.5 years after Harvey, and there was no clear seasonal pattern. A much longer time may be needed for the grain size to recover to pre-Harvey levels considering the extremely low base flows from the Mission and Aransas rivers to this system (Mooney and McClelland \u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Reyna et al. \u003cspan citationid=\"CR76\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). It is also possible that the median grain size will remain at a new, higher baseline. Further monitoring is needed to evaluate whether median grain size can recover to the level of pre-Harvey.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section2\"\u003e \u003ch2\u003eOC% in surface sediment showed resistance to Harvey\u003c/h2\u003e \u003cp\u003eAveraged across the 19 sampling sites, the bulk TOC% in sediments did not change significantly in October 2017 after Harvey, and there was no further change from January 2018 to March 2019 (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05), even though the median grain size generally increased after Harvey. The loss of TOC through fine sediments due to particle resuspension and export to the Gulf of Mexico might be balanced by the input of terrestrial debris from river input and storm surge, and the newly produced autochthonous organic matter from the overlying water column. First, the δ\u003csup\u003e13\u003c/sup\u003eC\u003csub\u003eorg\u003c/sub\u003e values became slightly depleted in October 2017 after Harvey, possibly indicating a source of terrestrial organic matter in the sediment. In particular, δ\u003csup\u003e13\u003c/sup\u003eC\u003csub\u003eorg\u003c/sub\u003e values at both sites S15 and S16 were much more depleted in October 2017 (-23.0 and \u0026minus;\u0026thinsp;23.3\u0026permil;, respectively) than in June 2017 before Harvey (-19.3 and \u0026minus;\u0026thinsp;20.6\u0026permil;, respectively). These two sites are located on the bayside of San Jose Island, where strong seaward storm surges were observed during Harvey (Goff et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Thus, when the seaward storm surge and current passed over the island, the terrestrial organic materials may have been carried away and redeposited to these nearshore sediments. Secondly, despite the strong resuspension and storm surge, phytoplankton biomass in the water column showed similar seasonal dynamics with the years before Harvey and was not significantly impacted by Hurricane Harvey (Douglas et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2023a\u003c/span\u003e). Additionally, the THAA concentrations in both water column (Douglas et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2023b\u003c/span\u003e) and sediment (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ed) in June 2018 were very similar to them in June 2017, indicating a quick recovery of the autochthonous OC in the MAE. Therefore, the newly produced particles from the water column may have rapidly deposited into the sediment and replenished the lost organic matter. The unchanged OC% in surface sediment showed its resistance to storm disturbance.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec21\" class=\"Section2\"\u003e \u003ch2\u003eChanges of phytoplankton communities and chloropigments in sediments\u003c/h2\u003e \u003cp\u003eThe microalgal community in the surface sediment, reconstructed from accessory pigments, reflects contributions from benthic microalgae and the algal material that recently settled from the water column. Therefore, the increase in cyanobacteria and decrease in diatom contributions in surface sediment immediately post-Harvey (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e), may indicate a similar shift in benthic microalgal and phytoplankton community in the water column, as confirmed by Douglas et al. (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2023a\u003c/span\u003e). They reported that a large amount of freshwater and nutrients were exported to the MAE after Harvey, which may have promoted cyanobacteria production in surface waters. Cyanobacteria blooms in low salinity waters have been reported previously after the passage of hurricanes (e.g., Paerl et al. \u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Glibert et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). For example, in the historically oligotrophic Florida Bay after the passages of Hurricanes Katrina, Rita, and Wilma, large blooms of \u003cem\u003eSynechococcus\u003c/em\u003e were sustained for 3 years (Glibert et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2009\u003c/span\u003e).\u003c/p\u003e \u003cp\u003ePheophorbide, a degradation product of Chl \u003cem\u003ea\u003c/em\u003e, is mainly produced in zooplankton guts after algal cells are digested (Shuman and Lorenzen \u003cspan citationid=\"CR79\" class=\"CitationRef\"\u003e1975\u003c/span\u003e; King and Repeta \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e1994\u003c/span\u003e; Lee et al. \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2000\u003c/span\u003e; Chen et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). Pheophorbide has been used to quantify benthic macrofaunal grazing intensity in intertidal sediment (Ford and Honeywill, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2002\u003c/span\u003e). The concentrations and proportions of pheophorbide in surface sediments of the MAE substantially decreased in October 2017 after Harvey, suggesting that zooplankton and other benthic macrofaunal species may have been severely impacted by the strong storm surge and resuspension. Consistent with these results, Montagna (\u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) reported that in San Antonio Bay, adjacent to the MAE, benthic macroinfaunal diversity, abundance, and biomass declined 54\u0026ndash;82% immediately following Hurricane Harvey, and the benthos community shifted from polychaetes to mollusks, likely due to decreased salinity and depletion of dissolved oxygen (DO). High amounts of precipitation and large freshwater inflow decrease salinity, and the decomposition of high terrestrial organic loads can lead to low DO conditions in the estuary following a storm (Van Dolah and Anderson \u003cspan citationid=\"CR85\" class=\"CitationRef\"\u003e1991\u003c/span\u003e; Mallin and Corbett \u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e2006\u003c/span\u003e), which affect certain species and diversity of the benthic community. A significant decline in total benthic habitats (dominated by opportunistic species mostly polychaetes) was also observed in the Northeast Cape Fear River, North Carolina, immediately after Hurricanes Bertha and Fran in 1996, and low DO and its slow recovery was thought to be the major reason for this decline (Mallin et al. \u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e1999\u003c/span\u003e). However, Hu et al. (\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) reported that the MAE did not experience a substantial DO decrease during and after Harvey, suggesting that the decline of benthic macrofaunal in the MAE was not related to hypoxic or anoxic conditions. Instead, it may have been due to either the significant reduced salinity (Montagna \u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e2023\u003c/span\u003e), or the strong resuspension and storm surge that can greatly erode surface sediment and thus directly impact the benthic habitat. Previous work showed that increased turbidity and sedimentation could cause benthic smothering once sediment settles out of the water (Henley et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2000\u003c/span\u003e; Davies-Colly and Smith 2001). The benthic macrofauna in the MAE appears to be recovering 7 months after Harvey, as the proportion of pheophorbide in chloropigments increased back to 15% in March 2018. The recovery of the benthos within 7 months after Harvey\u0026rsquo;s landfall is consistent with the observation in San Antonio Bay (within 8 months) after Hurricane Harvey and in Cape Fear Estuary of North Carolina (benthos recovery generally in 2\u0026ndash;4 months) after Hurricanes Bertha and Fran (Mallin et al. \u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e1999\u003c/span\u003e), indicating high resilience of benthic infauna to hurricane disturbance. These results suggest that pheophorbide is an excellent indicator of the health of the benthic community in surface sediments. This conclusion, however, may need to be confirmed by directly comparing chloropigments and benthic population.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec22\" class=\"Section2\"\u003e \u003ch2\u003eChanges of surface sediment PAHs\u003c/h2\u003e \u003cp\u003ePAHs are a group of organic contaminants that are widespread in today\u0026rsquo;s environment, with pyrogenic (mainly combustion of fossil fuel) and petrogenic (petroleum products) as the two main sources (Laflamme and Hites \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e1978\u003c/span\u003e; Wang et al. \u003cspan citationid=\"CR89\" class=\"CitationRef\"\u003e2001\u003c/span\u003e). PAHs are insoluble in water due to their high hydrophobicity, but strongly adsorbed onto particles and thus tend to be accumulated and preserved in sediments (Wang et al. \u003cspan citationid=\"CR89\" class=\"CitationRef\"\u003e2001\u003c/span\u003e). The pre-Harvey levels of PAHs in the MAE surface sediment (436\u0026thinsp;\u0026plusmn;\u0026thinsp;303 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) were comparable to those in the Mississippi River mouth, salt marsh, and coastal shelf of the northern Gulf of Mexico (100\u0026ndash;856 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, Wang et al. \u003cspan citationid=\"CR90\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), but much lower than those in highly industrialized and contaminated estuaries, such as the Passaic River (NJ, 145,000 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and the Newark Bay Estuary (44,000 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) (Huntley et al. \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e1995\u003c/span\u003e), suggesting that the MAE is not heavily contaminated by PAHs. Consistent with many earlier studies (e.g., Oros and Ross \u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e2004\u003c/span\u003e; Lubecki and Kowalewska \u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e2010\u003c/span\u003e), higher PAH concentrations in sediment are often associated with fine particles (grain size\u0026thinsp;\u0026lt;\u0026thinsp;63 \u0026micro;m) (Fig. S5c). However, the highest PAH concentration in this study (1401 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) occurred at site S07, despite a sediment median grain size of 84 \u0026micro;m. This is likely because site S07 was close to the city of Rockport boat launch area, which likely produced higher levels of PAHs due to gasoline and diesel leaking or combustion (Li et al. \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2003\u003c/span\u003e; Wang et al. \u003cspan citationid=\"CR90\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). In the MAE sediment, about 84% of PAHs were LMW prior to Harvey. Fossil fuels (e.g., diesel and gasoline, oil seeps, petroleum spills) tend to have more 2 to 3 ring LMW PAHs, while combusted fuels (e.g., vehicle exhaust, domestic heating with coal) are likely to contain more 4 to 5 ring HMW compounds (Van Metre et al. \u003cspan citationid=\"CR86\" class=\"CitationRef\"\u003e2000\u003c/span\u003e). Therefore, the dominance of LMW PAHs in MAE before Harvey indicated a major petrogenic source.\u003c/p\u003e \u003cp\u003ePAHs in MAE surface sediments significantly decreased to 103\u0026thinsp;\u0026plusmn;\u0026thinsp;66 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e following Harvey, compared to pre-Harvey levels (436\u0026thinsp;\u0026plusmn;\u0026thinsp;303 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). This decrease was likely caused by the strong physical disturbance inside the MAE, as fine particles, often enriched in PAHs, were resuspended from surface sediment, and then quickly flushed out of the MAE with a strong seaward outflow (Goff et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2019\u003c/span\u003e), as discussed above. The same magnitude loss of PAHs was also observed in lower sediment layers (5\u0026ndash;10 and 10\u0026ndash;15 cm) at site S09, indicating the physical disturbance on sediment could reach at least 10\u0026ndash;15 cm below sediment surface or the surface layer may have lost due to the strong storm surge (Goff et al., \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Consistently, Liu et al. (\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e2009\u003c/span\u003e) reported that following Hurricanes Katrina and Rita, fine organic carbon- and mercury-enriched sediments were substantially transported over the northern Gulf of Mexico continental shelf through physical redistribution, resulting in mercury input to the continental shelf approximately 5 times higher than its annual input from the Mississippi-Atchafalaya River system. In addition to the loss of finer minerals, the dramatic decrease in salinity in the MAE after Harvey, from 22.9 to 3.3, may have enhanced the solubility of PAHs (Oh et al. \u003cspan citationid=\"CR63\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Means \u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e1995\u003c/span\u003e; Turner \u003cspan citationid=\"CR83\" class=\"CitationRef\"\u003e2003\u003c/span\u003e), particularly when fine sediment particles were resuspended to the water column. A large fraction of PAHs in the sediments may have been re-dissolved into the water phase, and then either exported out of the system due to tides and currents or degraded microbially and photochemically (Langworthy et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2002\u003c/span\u003e; Clark et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). The release of PAHs from sediments may affect organisms in coastal ecosystems. Dissolved PAHs in water generally have higher bioavailability than those associated with particles (Laor et al., \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e1998\u003c/span\u003e), which could lead to higher risk of toxicity to the aquatic life (Yan et al. \u003cspan citationid=\"CR95\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Vijayanand et al. \u003cspan citationid=\"CR87\" class=\"CitationRef\"\u003e2023\u003c/span\u003e), making this a potential impact of hurricanes on estuaries that deserves more research.\u003c/p\u003e \u003cp\u003eThe loss of total PAHs was mainly sustained by the decrease in LMW PAHs (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), whereas concentrations of HMW PAHs did not change significantly after the hurricane (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e9\u003c/span\u003e). Preferential loss of LMW PAHs in oyster tissue has also been reported after Hurricanes Katrina and Rita in the Gulf of Mexico, suggesting that LMW and HMW PAHs respond differently to particle suspension and water salinity changes (Johnson et al. \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Different PAHs have different water solubilities and affinities for particles. Moreover, solubility decreases as molecular weight increases. Therefore, high-ring PAHs are more strongly bound by particles while low-ring PAHs have higher water solubility. Li et al. (\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) found that salinity had a more significant impact on the release behaviors of 2- and 3-ring PAHs than other individual PAHs species. In the low-salinity and high resuspension conditions following Harvey, LMW PAHs were preferentially dissolved in water and thus released from the sediment to water (Means \u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e1995\u003c/span\u003e; Turner \u003cspan citationid=\"CR83\" class=\"CitationRef\"\u003e2003\u003c/span\u003e, Soclo et al. \u003cspan citationid=\"CR80\" class=\"CitationRef\"\u003e2008\u003c/span\u003e). Since HMW PAHs in sediments did not change much after Harvey, the observed loss of total PAHs likely was a result of the release of LMW PAHs from sediments prompted by both sediment resuspension and the decrease in salinity. The monitoring of the LMW PAHs in the water column before and after a hurricane is needed in the future.\u003c/p\u003e \u003cp\u003eInterestingly, PAHs further decreased to 50\u0026thinsp;\u0026plusmn;\u0026thinsp;33 ng g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in Jan 2018, and did not recover even seven months after Harvey in March 2018. The persistence of low levels of PAHs in the system suggests that it may take a much longer time to accumulate enough contaminants to reach pre-Harvey levels. This is reasonable as the MAE has a long water residence time (up to 3 years), and pre-Harvey PAHs in sediments might have accumulated for years, maybe decades, considering that PAHs are one group of persistent organic pollutants that resist environmental degradation.\u003c/p\u003e \u003cp\u003e \u003cb\u003eChanges of\u003c/b\u003e \u003cb\u003en\u003c/b\u003e\u003cb\u003e-alkanes in surface sediments\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThe concentration changes of \u003cem\u003en\u003c/em\u003e-alkanes in surface sediments were consistent with those of PAHs: a strong decrease immediately after Harvey followed by persistently low levels. Considering their similar hydrophobicity, \u003cem\u003en\u003c/em\u003e-alkanes may have been associated with the same types of sedimentary organic matter and size fractions of particles as PAHs in the MAE. However, considering that all alkanes are rather insoluble, the loss of fine particles via sediment resuspension might be the main cause for the decrease of \u003cem\u003en\u003c/em\u003e-alkanes after Harvey.\u003c/p\u003e \u003cp\u003eAdditionally, the sources of \u003cem\u003en\u003c/em\u003e-alkanes in sediments are more complex than PAHs. In addition to anthropogenic sources (i.e., petroleum contamination), \u003cem\u003en\u003c/em\u003e-alkanes in sediments have biological sources, such as bacteria, algae, and terrestrial plants (Gogou et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2000\u003c/span\u003e), which have different \u003cem\u003en\u003c/em\u003e-alkane compositions (Ahad et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Frena et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). In general, \u003cem\u003en\u003c/em\u003e-alkanes derived from terrestrial plants have a strong odd-numbered predominance by long-chain compounds (C\u003csub\u003e25\u003c/sub\u003e-C\u003csub\u003e35\u003c/sub\u003e) (Eglinton and Eglinton \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2008\u003c/span\u003e). \u003cem\u003en\u003c/em\u003e-Alkanes sourced from bacteria, algae or phytoplankton, however, are dominated by short-chain compounds (C\u003csub\u003e12\u003c/sub\u003e-C\u003csub\u003e22\u003c/sub\u003e), and have an even-numbered predominance, although they are much less common (Grimalt and Albaiges \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e1987\u003c/span\u003e; Elias et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e1997\u003c/span\u003e). Petroleum oils consist of a highly complex mixture of hydrocarbons, and generally have a short-chain (C\u003csub\u003e15\u003c/sub\u003e-C\u003csub\u003e25\u003c/sub\u003e) dominance on \u003cem\u003en\u003c/em\u003e-alkanes with no odd/even predominance (Connell et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e1980\u003c/span\u003e,\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e1981\u003c/span\u003e; Harb et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2003\u003c/span\u003e; Frena et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Jafarabadi et al. \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2018\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eBefore Harvey, C\u003csub\u003e16\u003c/sub\u003e was the dominant alkane, which is an indicator of sediments contaminated with crude oil (Jafarabadi et al. \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). However, \u003cem\u003en\u003c/em\u003e-alkanes dominated by petroleum compounds are usually identified by little or no odd/even predominance in the C\u003csub\u003e12\u003c/sub\u003e-C\u003csub\u003e25\u003c/sub\u003e range (Connell et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e1980\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e1981\u003c/span\u003e; Frena et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Jafarabadi et al. \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Our results showed the dominance of even-numbered C\u003csub\u003e14\u003c/sub\u003e-C\u003csub\u003e22\u003c/sub\u003e, with C\u003csub\u003e16\u003c/sub\u003e as the most abundant moiety, a pattern that instead indicated a diatom source (Elias et al., \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2000\u003c/span\u003e). Bacterially-produced \u003cem\u003en\u003c/em\u003e-alkanes are also dominated by one or two even-numbered compounds in the C\u003csub\u003e12\u003c/sub\u003e-C\u003csub\u003e22\u003c/sub\u003e range, especially C\u003csub\u003e18\u003c/sub\u003e and C\u003csub\u003e20\u003c/sub\u003e (Elias et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e1997\u003c/span\u003e). Similarly, a dominance of C\u003csub\u003e16\u003c/sub\u003e was found in surface sediments of the Nueces Delta, an adjacent area dominated by seagrass and marsh plants (Liu et al. \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). These results, therefore, indicated that biogenic sources, such as algae or seagrass, contributed to the C\u003csub\u003e16\u003c/sub\u003e and other short-chained \u003cem\u003en\u003c/em\u003e-alkanes.\u003c/p\u003e \u003cp\u003eThe percentage of C\u003csub\u003e16\u003c/sub\u003e decreased greatly from 22% in June 2017 pre-Harvey to 12% in October 2017 after Harvey, and this trend continued to decrease to 5% by March 2018. This pattern suggested a loss of biogenic materials enriched in C\u003csub\u003e16\u003c/sub\u003e, either due to degradation or lateral export. In contrast, the percentages of C\u003csub\u003e14\u003c/sub\u003e, C\u003csub\u003e18\u003c/sub\u003e and C\u003csub\u003e20\u003c/sub\u003e \u003cem\u003en-\u003c/em\u003ealkanes increased in October 2017 relative to June 2017, suggesting temporary input of diatom or bacteria to the surface sediment two months after Hurricane Harvey, possibly due to high nutrient input to the MAE and the enhanced phytoplankton biomass after the hurricane (Elisa et al. 2000; Douglas et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2023a\u003c/span\u003e). Similarly, the percentages of long-chained \u003cem\u003en\u003c/em\u003e-alkanes C\u003csub\u003e29\u003c/sub\u003e-C\u003csub\u003e31\u003c/sub\u003e increased, likely as a result of more relative contribution of land vascular plants (Yunker et al. \u003cspan citationid=\"CR96\" class=\"CitationRef\"\u003e2011\u003c/span\u003e) and their resistance to degradation. Therefore, the impact of Harvey on \u003cem\u003en\u003c/em\u003e-alkanes in the surface sediments appears to be long lasting, similar to PAHs, and further research is needed to evaluate the time scale of recovery.\u003c/p\u003e \u003cdiv id=\"Sec23\" class=\"Section3\"\u003e \u003ch2\u003eConclusions and implication\u003c/h2\u003e \u003cp\u003eA hurricane is a unique climate event in which an estuary system might simultaneously experience a storm surge, sediment resuspension, and a decrease in salinity. Here we evaluated the effects of a major hurricane on the sediment geochemistry of a shallow estuary in south Texas using a comprehensive series of parameters, including sediment grain size, bulk organic carbon and stable carbon isotopes, and several organic compound classes that can indicate different biogeochemical processes. The median grain size of the MAE surface sediment significantly increased after Hurricane Harvey, likely because of strong resuspension and further storm surge and currents that transported the finer minerals elsewhere, including offshore. After Harvey, the grain size remained coarser for at least 1.5 years, suggesting that a new baseline may have been established. While the bulk organic carbon and stable carbon isotopes were not affected noticeably by the hurricane, the labile fractions of the organic matter, including THAA and pigments, decreased slightly immediately following the hurricane (1\u0026ndash;2 months), but recovered in 7 months, suggesting a quick replenishment of labile organic matter to sediments from the overlying water column or benthic activities. The levels of pheophorbide, a biomarker indicating zooplankton and benthic macrofaunal activities, decreased significantly over the entire MAE right after Harvey, suggesting immediate severe impacts on the activities of zooplankton and benthic macrofaunal species, although they seemed to have fully recovered in 7 months from the biomarker perspective.\u003c/p\u003e \u003cp\u003eWhile bulk organic matter and its labile fractions are continuously replenished by sources from the water column, the impact of Harvey on sedimentary PAHs and \u003cem\u003en\u003c/em\u003e-alkanes, two groups of hydrophobic compounds, resulted in a contrasting pattern. Concentrations of both PAHs and \u003cem\u003en\u003c/em\u003e-alkanes decreased in as many as 5-10-fold after Harvey, likely lost to the water column due to strong sediment resuspension and the enhanced solubility in fresh water, or to the open Gulf of Mexico through the transport of finer minerals with adsorbed compounds. They had not recovered to the pre-Harvey levels after 1.5 years, suggesting that it may take multiple years or decades for these compounds to reconcentrate in surface sediment. It also suggests that hurricanes might play an important role in remobilizing and redistributing estuarine organic contaminates such as PAHs, thus monitoring the water quality of estuaries for these compounds may be necessary after major hurricanes. Overall, this study provided the first systematic data on how a major hurricane impacts the sediment geochemistry in a shallow estuary through strong resuspension, storm surge, and temporary freshening. The impacts on specific organic compound classes differed greatly or were completely decoupled, depending on their sources and association with minerals, thus these chemical classes may be useful to trace different biogeochemical impacts.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflict of Interest \u0026nbsp;\u0026nbsp;\u003c/strong\u003eThe authors declare no conflict of interests.\u003cstrong\u003e\u003cbr\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe original data used in this manuscript can be accessed through BCO-DMO (https://www.bco-dmo.org/dataset/839436).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to thank the Mission Aransas National Estuarine Research Reserve director Jace Tunnel, and research coordinator Dr. Ed Buskey, as well as technicians Kelley Savage and Cammie Hyatt. We also thank Dr. Rong Chen, Dengzhou Gao, Xiangtao Jiang, and Elizabeth Schattle for help with sample processing. Dr. Ryan Hladyniuk helped with CHN and isotope analysis. Funding for this study was provided by Texas Sea Grant (#M1801875 to AH and ZL) and ConTex (joint initiative of The University of Texas System and Mexico\u0026rsquo;s CONACYT, #2019-63A to ZL), and the National Science Foundation Chemical Oceanography Program (RAPID #1763167 to ZL and AH).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAdams, S. M., M. S. Greeley, J. M. Law, E. J. Noga, and J. T. Zelikoff. 2003. 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Alkane and PAH biomarkers as tracers of terrigenous organic carbon in Arctic Ocean sediments. \u003cem\u003eOrganic Geochemistry\u003c/em\u003e 42: 1109\u0026ndash;1146.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"estuaries-and-coasts","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"esco","sideBox":"Learn more about [Estuaries and Coasts](https://www.springer.com/journal/12237)","snPcode":"12237","submissionUrl":"https://www.editorialmanager.com/esco/","title":"Estuaries and Coasts","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Hurricane Harvey, Estuary, Sediment resuspension, Grain size, Pigments, PAHs and n-alkanes","lastPublishedDoi":"10.21203/rs.3.rs-4572090/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4572090/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMajor hurricanes can greatly affect sediment biogeochemical processes in coastal bays and estuaries through strong storm surges and resuspension, yet the impacts on sediment geochemistry have rarely been evaluated. Here the sediment geochemistry of the Mission Aransas Estuary, Texas, was systematically evaluated prior to and after Hurricane Harvey, a Category 4 storm. The median grain size of the surface sediments in the estuary significantly increased, but the bulk sediment total organic carbon content (TOC%) remained relatively constant. The concentration and composition of several organic chemical classes in the sediment were altered in distinctly different patterns. Accessory pigments showed that cyanobacterial materials in surface sediments increased immediately after Harvey, but returned to pre-Harvey levels five months post-hurricane. Pheophorbide decreased significantly after Harvey, but also recovered within seven months, suggesting resilience of the benthic community. In contrast, polycyclic aromatic hydrocarbons (PAHs) and \u003cem\u003en\u003c/em\u003e-alkanes decreased (5-10-fold) five months after Hurricane Harvey and remained low one year later. The loss of PAHs and \u003cem\u003en\u003c/em\u003e-alkanes from the sediment might be related to increased solubility due to decreased salinity and strong resuspension during the storm surge. Overall, the strong storm surge and resuspension of sediment by Hurricane Harvey presented a major disturbance to the geochemistry of surface sediment in the MAE, but the impact on individual organic chemical classes depended on their sources, chemical properties, and/or association with fine clay minerals.\u003c/p\u003e","manuscriptTitle":"The impact of a major hurricane on sediment geochemistry of a shallow subtropical estuary through strong resuspension","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-07-10 15:07:18","doi":"10.21203/rs.3.rs-4572090/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2024-06-18T23:26:17+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-06-17T03:51:31+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Estuaries and Coasts","date":"2024-06-13T17:29:23+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-06-13T04:53:28+00:00","index":"","fulltext":""},{"type":"submitted","content":"Estuaries and Coasts","date":"2024-06-12T14:52:35+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"estuaries-and-coasts","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"esco","sideBox":"Learn more about [Estuaries and Coasts](https://www.springer.com/journal/12237)","snPcode":"12237","submissionUrl":"https://www.editorialmanager.com/esco/","title":"Estuaries and Coasts","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"a37b1bc1-4b8d-4b83-bebe-5cfb2e92326d","owner":[],"postedDate":"July 10th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-11-04T16:26:35+00:00","versionOfRecord":{"articleIdentity":"rs-4572090","link":"https://doi.org/10.1007/s12237-024-01432-w","journal":{"identity":"estuaries-and-coasts","isVorOnly":false,"title":"Estuaries and Coasts"},"publishedOn":"2024-10-29 16:20:17","publishedOnDateReadable":"October 29th, 2024"},"versionCreatedAt":"2024-07-10 15:07:18","video":"","vorDoi":"10.1007/s12237-024-01432-w","vorDoiUrl":"https://doi.org/10.1007/s12237-024-01432-w","workflowStages":[]},"version":"v1","identity":"rs-4572090","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4572090","identity":"rs-4572090","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}