Community Structure of Meiofauna and Its Environmental Drivers in Huanghua Port, Bohai Bay

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Meiofaunal assemblages were dominated by free-living nematodes, followed by copepods, ostracods, and polychaetes. The mean abundance of meiofauna was 161.44 ± 7.51 ind./10 cm², with nematodes accounting for 70.8% of the total abundance. Meiofaunal abundance differed between stations, with higher values observed at the nearshore site. Statistical analysis revealed that water depth, salinity, and transparency were identified as the primary environmental drivers influencing community structure. The abundances of nematodes, polychaetes, and ostracods were significantly negatively correlated with water depth and transparency ( p < 0.05), and positively correlated with salinity ( p < 0.05). In contrast, copepod abundance was significantly correlated only with nitrate concentration ( p < 0.05). The nematode-to-copepod ratio (N/C) ranged from 3.87 to 4.39, indicating relatively low levels of organic pollution in the study area. However, given the limited spatial scale of sampling, this indicator should be interpreted with caution. Overall, this study provides baseline data on meiofaunal community structure and its environmental responses in Huanghua Port, contributing to ecological assessment and coastal management. Huanghua Port Meiofauna Community structure Environmental drivers Coastal ecosystem Figures Figure 1 Figure 2 Figure 3 Introduction As the intensity of coastal development continues to increase, marine ecological environment issues are becoming increasingly prominent. Human activities such as nearshore aquaculture and industrial wastewater discharge have already had a significant impact on the marine ecosystem (Schratzberger et al.,2018), leading to water quality deterioration, habitat degradation, and a decline in biodiversity. Huanghua Port is located in a silty–mud coastal zone of the Bohai Bay (Bao et al.,2026). Influenced by river inputs and marine dynamics, the sedimentary environment is complex and nutrient-rich, with abundant plankton and meiofauna (Gao et al.,2015). However, with the industrialization of coastal cities and the discharge of large amounts of pollutants into the sea, conducting research on the ecological environment and biological community characteristics of this sea area is of great significance for understanding the regional ecological status and its trends. In 1942, Mare first referred to a type of sessile benthic invertebrates smaller than large benthic animals as "Meiofauna" (i.e., Meiofauna) (Hong et al.,2025). Meiofauna are defined as metazoans that pass through a 500 µm sieve but are retained by a 42 µm or 31 µm mesh sieve (Zhu et al.,2022; Zhou et al.,2025; Zhu et al.,2023; Zhang et al.,2022). They include both permanent and temporary benthic organisms (Chu et al.,2022). Meiofauna, as an important component of marine benthic ecosystems, serve as a food source for the larvae of many fish, shrimp, and mollusks, and play a regulatory role in the production and consumption of microorganisms and bacteria (Cai, 2013 ). They primarily feed on detritus and heterotrophic bacteria in the seabed sediments (Zou,2006), and are an indispensable part of the coupling process of benthic ecosystems in the water column, play a key role in benthic food webs and nutrient cycling (Ecology, 2020 ). Due to their short life cycles and sensitivity to environmental changes, studies have shown that meiofauna can serve as important biological indicators of environmental pollution and climate change (Coull et al.,1988; Zhang et al.,2019; Marine,2018; Higgins,2020). Therefore, conducting ecological environment assessments based on the characteristics of small benthic communities holds significant research value. Currently, research on Meiofauna in the waters of Huanghua Port is still relatively limited, especially in the context of port development and human activities, where systematic analysis of their community structure and environmental response characteristics is still lacking. In recent years, with the continuous strengthening of aquaculture activities and port development, the regional water bodies and sedimentary environments have been constantly changing, which may have significant impacts on the benthic community. Therefore, research in the waters near Huanghua Port remains limited and requires further investigation. This study collected sediment samples from two different sites near Huanghua Port to explore the community structure, biomass, and their relationships with environmental factors of Meiofauna in the vicinity of Huanghua Port. The aim is to observe the water quality and pollution levels in the waters near Huanghua Port, providing scientific data support for the assessment of fishery resources and environmental conditions in the Bohai Bay near Huanghua Port. Materials & Methods Sampling Time and Location This study set up two sampling stations near Huanghua Port in the Bohai Bay area in May 2018 to conduct the investigation. Station 1: 38°21.032'N, 117°56.317'E, Station 2: 38°31′58.8″N, 118°7′12″E. (Fig. 1 ), each station was set up with 3 replicate samples, totaling 6 undisturbed sediment samples collected. Sample Collection Methods and Laboratory Analysis Onsite, a QNC6 stainless steel grab sampler was used to collect sediment samples. Under undisturbed conditions, a sampling tube with an inner diameter of 2.6 cm was used to randomly collect core samples (depth 8 cm), which were then bottled in layers according to 0–2 cm, 2–5 cm, and 5–8 cm. A suitable amount of 10% formaldehyde solution was added for fixation and preservation, to be used for the analysis of meiofauna. Additionally, some sediment samples were sealed and frozen at -20°C for the measurement of environmental factors. Environmental parameters were measured using a YSI probe some environmental factors on-site, including water temperature (Temp), pH, salinity (Salinity). The turbidity used the Secchi disk method. Water depth was obtained using a shipboard sensor. In the laboratory, after thawing the samples, 5 ml of Bengal rose dye was added and left to stain for 24 hours. The meiofauna were then sorted using a double-layer sieve with mesh sizes of 500 µm and 42 µm (Qiao et al.,2021). The Meiofauna were separated using the Ludox-TM centrifugation method, repeated three times. Samples were transferred to Petri dishes for classification, identification, and counting under a stereomicroscope, and preserve the samples in 75% alcohol for future use. Given that the sediment in the waters near Huanghua Port is primarily silt, this study employed the flotation sedimentation method for sample washing and sorting. The experimental treatment and data statistical methods were the same as those used by Qiao Chunyan et al. (Kosmala et al.,2026). Nitrite (NO₂ ⁻ ), ammonia nitrogen (NH₃-N), nitrate (NO 3 ⁻ ), soluble phosphate (SRP), and reactive silicate (SiO₃-Si) were determined according to the "Marine Monitoring Specification Part 4" (GB 17378.4–2007), using the naphthyl ethylenediamine spectrophotometric method, hypobromite oxidation method, cadmium column reduction method, molybdenum blue spectrophotometric method, and silicomolybdenum blue spectrophotometric method, respectively. The abundance ratio of nematodes to copepods (N/C) is usually used as a reference indicator for the environment. An N/C < 50 indicates that the sediment environment is normal; 50 < N/C 100 indicates the presence of organic pollution in the sediment (Gordillo et al.,2025). Data Management and Analysis ArcGIS was used to create station maps. To study the relationship between environmental factors and benthic organisms, Origin was used to plot the distribution map of meiofauna abundance. Using SPSS 31.0 software, the data were subjected to normality tests, and one-way ANOVA was employed to compare the differences in the abundance of Meiofauna at different stations. Pearson correlation analysis was used to explore the relationship between the abundance of major groups and environmental factors, with a significance level set at p < 0.05. In addition, the PRIMER 6.0 software was used to calculate the community diversity index and perform multivariate analysis to reveal the relationship between the structure of meiofauna communities and environmental factors (Ingels et al.,2011). Research Results Composition, Abundance, and Biomass of Different Benthic Invertebrate Groups at Different Stations Meiofaunal communities consisted mainly of Meiofauna in the waters of Huanghua Port in the Bohai Bay, four main groups of meiofauna were identified: free-living marine nematodes (Nematoda), benthic copepods (Copepoda), ostracods (Ostracoda), and polychaetes (Polychaeta). The remaining groups were classified as "other groups." Overall, free-living marine nematodes are the dominant group, accounting for 70.8% of the total abundance of meiofauna, followed by benthic copepods, ostracods, and polychaetes. The abundance of meiofauna varied among stations (Fig. 2 ). At Station 1, the abundance of free-living marine nematodes was 182.16 ± 10.97 ind./10 cm², benthic copepods were 47.11 ± 13.53 ind./10 cm², ostracods were 35.18 ± 12.50 ind./10 cm², polychaetes were 8.17 ± 0.58 ind./10 cm², and other groups were 5.65 ± 1 ind./10 cm²; at Station 2, the abundance of free-living marine nematodes was 140.71 ± 4.04 ind./10 cm², benthic copepods were 32.04 ± 1.73 ind./10 cm², ostracods were 6.91 ± 2.08 ind./10 cm², polychaetes were 3.77 ± 0 ind./10 cm², and other groups were 6.91 ± 1.54 ind./10 cm². Overall, the abundance of various groups at Station 1 is higher than at Station 2. By comparing experimental data, free-living marine nematodes were found to be the dominant population at both sampling sites, followed by benthic copepods. Further analysis revealed that although the composition of meiofauna communities at the two sampling sites near Huanghua Port was similar, there were differences in biological abundance. This was due to variations in other environmental factors such as water depth, temperature, sediment organic matter content, and transparency. The Ratio of Nematodes to Copepods Abundance (N/C) at Different Stations Table 1 N/C values of Meiofauna at different stations Abundance Station 1 Station 2 Nematodes(ind./10 cm 2 ) 140.71 ± 4.04 182.16 ± 10.97 Benthos copepods(ind./10 cm 2 ) 32.04 ± 1.73 47.11 ± 13.53 N/C 4.39 3.87 The two main groups of meiofauna (nematodes and copepods) exhibit certain differences in their tolerance to environmental disturbances and organic pollution. Copepods have a lower tolerance to organic pollution, while nematodes have a higher tolerance, allowing them to have greater abundance in waters with organic pollution. Therefore, by comparing the abundance ratio of free-living marine nematodes to benthic copepods at two sites, we can infer whether the waters near Huanghua Port are affected by organic pollution and assess the overall ecological condition. The N/C value at Huanghua Port (Table 1 ) shows that the abundance of free-living marine nematodes and benthic copepods are 182.16 ± 10.97 ind./10 cm² and 47.11 ± 13.53 ind./10 cm², respectively, corresponding to an N/C value of 3.87. At Station 2, the abundances are 140.71 ± 4.04 ind./10 cm² and 32.04 ± 1.73 ind./10 cm², respectively, corresponding to an N/C value of 4.39. In the comparison of N/C ratios at different stations, results showed that the N/C value at station 1, which is closer to the coast, is relatively higher, while the N/C value at station 2, which is farther from the coast, is lower. This pattern may be attributed to the geographical location of the stations. Station 1, being closer to the estuary and near the industrial discharge area, has a relatively higher organic matter content, which in turn affects the N/C ratio. In contrast, Station 2 is far from these potential pollution sources, has lower organic matter content, and therefore a relatively lower N/C ratio. However, overall, the sedimentary environments at both sites are relatively good. The Correlation Between the Abundance of Meiofauna and Environmental Factors This study analyzes the correlation between the abundance of major groups of Meiofauna and environmental factors thru correlation analysis, presenting the results of their association (Table 2 ). Table 2 Correlations between the abundance of meiofauna in the Yellow and Bohai Seas and environmental factors. Depth Nematodes Copepods Polychaetes Amphipods Other N/C ratio -0.974* -0.657 -0.996* 0.974* 0.759 0.999* Temp 0.044 0.726 0.309 0.408 -0.345 -0.256 S 0.964* 0.679 0.997* 0.979* -0.771 -0.998* SDD -0.977* -0.651 -0.996* -0.972* 0.758 0.999* NO₂ ⁻ -0.490 -0.455 -0.528 -0.527 0.066 0.510 NH₃-N 0.592 -0.228 0.376 0.264 -0.208 -0.424 T-NO₂ ⁻ 0.560 -0.391 0.296 0.173 -0.311 -0.362 NO₃ ⁻ -N 0.445 0.991* 0.675 0.773 -0.190 -0.615 SRP -0.295 -0.408 -0.427 -0.437 0.787 0.419 SiO₃-Si -0.524 0.388 -0.275 -0.147 0.248 0.335 Note: *Correlation is significant at the 0.05 level. Overall, depth (Depth), salinity (S), transparency (SDD), and N/C ratio have a significant correlation with the structure of meiofauna communities, while factors such as Temp, NO₂ ⁻ , NH₃-N, NO3 ⁻ , SRP, and SiO₃-Si do not show a significant correlation with the abundance of most groups. Table 3 Relationship between variables of meiofauna in the Yellow and Bohai Seas and environmental factors. Depth Nematodes Copepods Polychaetes Amphipods Other N/C ratio S d J’ H′ -0.974* -0.657 -0.996* -0.974* 0.759 0.999* 0.289 0.272 0.237 0.281 Temp 0.044 0.726 0.309 0.408 -0.345 -0.256 -0.845 -0.816 -0.968* -0.921* S 0.964* 0.679 0.997* 0.979* -0.771 -0.998* -0.322 -0.304 -0.279 -0.319 SDD -0.977* -0.651 -0.996* -0.972* 0.758 0.999* 0.279 0.262 0.226 0.270 NO₂ ⁻ -0.490 -0.455 -0.528 -0.527 0.066 0.510 -0.345 -0.356 -0.259 -0.305 NH₃-N 0.592 -0.228 0.376 0.264 -0.208 -0.424 0.714 0.712 0.770 0.744 T-NO₂ ⁻ 0.560 -0.391 0.296 0.173 -0.311 -0.362 0.482 0.469 0.649 0.563 NO₃ ⁻ -N 0.445 0.991* 0.675 0.773 -0.190 -0.615 -0.597 -0.594 -0.583 -0.598 SRP -0.295 -0.408 -0.427 -0.437 0.787 0.419 0.597 0.543 0.782 0.712 SiO₃-Si -0.524 0.388 -0.275 -0.147 0.248 0.335 -0.750 -0.751 -0.791 -0.772 Note: *Correlation is significant at the 0.05 level. Specifically, the abundance of the three dominant groups—nematodes, polychaetes, and ostracods—exhibits highly similar environmental response patterns: the abundance of all three is significantly negatively correlated with depth and transparency ( p < 0.05) and significantly positively correlated with salinity ( p < 0.05). The environmental correlation of benthic copepods shows a significant difference compared with the aforementioned three dominant groups. Their abundance is only significantly positively correlated with the concentration of nitrate (NO₃ ⁻ -N) ( p < 0.05) and shows no significant correlation with depth, salinity, SDD, and other environmental factors. This result indicates that nitrate may be the key environmental factor regulating the abundance of copepods. The abundance of other groups did not show significant correlations with any environmental factors ( p > 0.05), indicating that their distribution is less influenced by the environmental factors monitored in this study and is more significantly affected by other unmonitored factors (food resources, substrate type, biological disturbances, etc.). The N/C ratio is significantly positively correlated with depth and SDD ( p < 0.05), and significantly negatively correlated with salinity ( p < 0.05). This indicates that with increasing water depth, higher transparency, and lower salinity, the N/C ratio of Meiofauna in the water body will significantly increase. This result also confirms the impact of differences in organic matter input and pollution levels between different sites on the aquatic environment and meiofauna (Cao et al.,2015). Overall, the community structure of Meiofauna is influenced by various environmental factors, and the best combination of environmental factors to explain the community structure is depth, transparency, and salinity. Discussion Meiofaunal abundance and community composition The present study shows that meiofaunal communities in the nearshore waters of Huanghua Port are dominated by nematodes, which accounted for more than 70% of the total abundance. This dominance pattern is consistent with previous studies conducted in coastal and estuarine ecosystems in China, where nematodes typically represent the most abundant meiofaunal group (Li et al., 2022 ; Kim et al., 2025 ; Cao et al., 2018 ). The ecological success of nematodes is generally attributed to their high tolerance to environmental stress, short life cycles, and broad feeding strategies, which allow them to adapt to fluctuating and disturbed habitats (Coull, 1988 ). However, the overall abundance of meiofauna in Huanghua Port was relatively low compared with other coastal regions such as the Yangtze River estuary and the Tangshan Sandao area (Zhang et al., 2006; Cao et al., 2015 ). This difference may be explained by the relatively unstable sediment conditions and strong hydrodynamic disturbance in the study area. Shallow coastal environments influenced by port activities and sediment resuspension often exhibit reduced habitat stability, which can limit meiofaunal colonization and reduce overall abundance. In addition, the relatively simple community composition observed in this study, with only a few dominant taxa, suggests a degree of environmental disturbance. Previous studies have shown that simplified community structures and dominance of tolerant taxa are typical features of disturbed coastal ecosystems (Schratzberger and Somerfield, 2020 ). Therefore, the meiofaunal community in Huanghua Port likely reflects the combined effects of natural environmental variability and anthropogenic disturbance. Table 4 c omparison of Meiofaunal Abundance in This Study with Those in Other Sea Areas Study area Sampling time Abundance ind./10cm² Proportion of nematodes Ref. Huanghua Port coastal waters 2018.May 228.04 70.8% this study Tangshan Sandao sea area 2013.May. Aug. Oct 735.2 > 95% Li et al.,2022 Yangtze River Estuary and Adjacent Continental Shelf Sea 2006.Jul-Aug 453.22 81.37% Kim et al.,2025 Qinhuangdao coastal waters 2013.May. Sep. Oct 695.26 93.01% Cao et al.,2018 Environmental drivers of meiofaunal distribution This study identified water depth, salinity, and transparency as the primary environmental factors influencing meiofaunal community structure, which is consistent with findings from other coastal regions (Mao et al., 2016 ; Yang et al., 2020 ; Yu et al., 2024 ). These factors influence meiofaunal distribution through their effects on sediment characteristics, food availability, and habitat stability. The negative relationship between meiofaunal abundance and water depth observed in this study may be related to reduced organic matter input and lower biological activity in deeper waters. Shallow areas typically receive higher inputs of organic detritus and experience stronger benthic–pelagic coupling, which enhances food availability for meiofauna (Zhang et al., 2009 ). Similarly, the negative correlation with transparency suggests that areas with higher suspended particles and organic matter may provide more favorable feeding conditions for detritivorous organisms. Salinity showed a significant positive correlation with the abundance of several dominant groups, indicating that relatively stable marine conditions favor meiofaunal development. In estuarine environments, fluctuations in salinity can impose physiological stress on benthic organisms, whereas stable salinity conditions promote community stability and diversity (Cai et al., 2002 ). In contrast to other groups, copepods showed a significant positive correlation only with nitrate concentration, suggesting that their distribution is more strongly influenced by nutrient availability than by physical environmental factors. This finding reflects differences in ecological niches and feeding strategies among meiofaunal taxa. Copepods are often more sensitive to food quality and nutrient conditions, which may explain their distinct response pattern. N/C ratio and environmental assessment The nematode-to-copepod ratio (N/C) has been widely used as an indicator of environmental quality due to the contrasting responses of these two groups to organic pollution (Raffaelli et al., 2009). In this study, N/C values ranged from 3.87 to 4.39, which are well below the threshold values typically associated with organic pollution. This suggests that the sedimentary environment in Huanghua Port is relatively unpolluted. However, the interpretation of the N/C ratio should be approached with caution. Several studies have highlighted that this index can be influenced by multiple factors, including sediment type, hydrodynamic conditions, and species-specific ecological traits (Hao et al., 2022). For example, nematodes are known to tolerate organic enrichment, while copepods are more sensitive and tend to decline under polluted conditions. Nevertheless, variations in substrate type and habitat structure may also affect their relative abundance. The slightly higher N/C ratio observed at the nearshore station may reflect increased organic input associated with human activities such as aquaculture and industrial discharge. In contrast, the offshore station, which is less influenced by anthropogenic inputs, exhibited lower N/C values. Similar spatial patterns have been reported in other coastal systems, where nearshore areas are more affected by organic enrichment (Cao et al., 2015 ). Despite its usefulness, the N/C ratio alone may not fully capture the complexity of benthic environmental conditions, particularly at small spatial scales (Subhra et al.,2023; Katlyn et al.,2023). Therefore, it is recommended that this index be used in combination with other biological and environmental indicators to provide a more comprehensive assessment of ecosystem health (Lü,2025). Implications for coastal ecosystem management The results of this study indicate that meiofaunal communities in Huanghua Port are shaped by both environmental gradients and human activities (Élise et al.,2020). The dominance of tolerant taxa and relatively low diversity suggest that the ecosystem is subject to a certain level of disturbance, although not severely polluted (Environmental,2020; Hual and Liu Xiaoshu,2024). Meiofauna can serve as effective bioindicators due to their rapid response to environmental changes, low sampling cost, and minimal environmental impact during monitoring (Sautya et al., 2024 ). Therefore, incorporating meiofaunal analysis into routine ecological monitoring programs could improve the assessment of coastal environmental quality. Overall, this study provides important baseline data for understanding the ecological status of Huanghua Port and highlights the need for continued monitoring under increasing anthropogenic pressure. Future studies should expand spatial and temporal sampling to better capture variability and improve the reliability of ecological assessments. Conclusion Based on the survey data from the nearshore waters of Huanghua Port in May 2018, this study analyzed the community structure characteristics of meiofauna and their relationship with environmental factors. The results indicate that a total of five groups of meiofauna were identified, with marine nematodes being the dominant group. The community composition was simple, primarily consisting of pollution-tolerant types, reflecting the impact of the disturbed nearshore environment. Abundance shows significant spatial differentiation: nearshore stations are higher than offshore stations, and overall abundance is lower than that in Jiaozhou Bay. Water depth, salinity, and transparency are the main environmental factors regulating community structure. The abundance of nematodes, polychaetes, and ostracods exhibited consistent response trends, showing a significant negative correlation with water depth and transparency ( p < 0.05), and a significant positive correlation with salinity ( p < 0.05). In contrast, the abundance of benthic copepods was only significantly positively correlated with nitrate ( p < 0.05), indicating ecological differentiation in the response of different groups to environmental factors. The N/C ratio at the two stations indicates that the ecological environment of this sea area is good. In summary, the structure of the benthic macrofauna community in the nearshore waters of Huanghua Port is jointly influenced by environmental factors and human activities. The characteristics of this community can serve as effective indicators for regional ecological environment assessment and provide fundamental data support for ecological monitoring and restoration in this area. Declarations Funding This study was supported by the National Natural Science Foundation of China (Youth Fund Project) (No. 32503188) and the Scientific Research Project of Higher Education Institutions in Hebei Province (No. QN2026778). Author Contribution Z is responsible for writing the article, data analysis, and creating images. L and M are in charge of sampling and conducting experiments, obtaining experimental results, and checking the article format. P and C guide the experiments and provide technical support. Acknowledgement This study was supported by the National Natural Science Foundation of China (Youth Fund Project) (No. 32503188) and the Scientific Research Project of Higher Education Institutions in Hebei Province (No. QN2026778). References Bao JJ, He YY, Liu XS (2026) Spatial and temporal distribution of meiofauna and the influencing environmental factors in Jiaozhou Bay. 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Hubbard and Colleagues (Benthic studies in upper Buzzards Bay, Massachusetts: 2011/12 as compared to 1955). Ecology Environment & Conservation Mao SQ, Lin X, Luo Y, Zhu YF, Yan XJ (2016) Community structure of meiofauna and its correlation with environmental factors in Xiangshan Bay. Ecol Sinica 36(5):1442–1452 (in Chinese) Qiao CY, Hao YD, Lu Y, Huang Y (2021) Preliminary study on biomass and biodiversity of free-living nematodes in intertidal zone of northern South China Sea. J Liaocheng Univ (Natural Sci Edition) 34(02):65–72. 10.19728/j.issn1672-6634.2021.02.009 (in Chinese) Ocean Research (2020) Data on Ocean Research Discussed by Researchers at University of Brest [Metal Partitioning After In Situ Filtration At Deep-sea Vents of the Lucky Strike Hydrothermal Field (Emso-azores, Mid-atlantic Ridge, 37 Degrees N). Ecology, Environment & Conservation, HigginsRP,ThielH.Introduction to the Study of Meiofauna.Washington,DC:Smithsonian Institution Press,1988 Sautya S, Gaikwad S, Ram A, Basu U, Molla N, Chatterjee T (2024) Assessment of Benthic Meiofauna in Multi-Stressed Environment. Thalassas: Int J Mar Sci 41(1):9–9. 10.1007/S41208-024-00755-6 . of a Tropical Estuary: a Case Study Using Low Taxonomic Resolution Data Subhra SB, Ahmed S, Sumit M, Cahandra TS (2023) Unveiling the meiobenthic community structure of Prydz bay, Antarctica during austral summer. Deep-Sea Res Part I 199. 10.1016/J.DSR.2023.104109 Song YL, Liu XS (2023) Spatial distrib55ution patterns of meiofauna and the influencing environmental factors in the southern Yellow Sea in summer and autumn. Haiyang Xuebao 45(1):38–52. 10.12284/hyxb2023020 (in Chinese) Schratzberger M, Somerfield PJ (2020) Effects of widespread human disturbances in the marine environment suggest a new agenda for meiofauna research is needed. Sci Total Environ 728:138435. 10.1016/j.scitotenv.2020.138435 Species composition and distribution of marine nematode community in the North Taiwan Strait (2001) Acta Oceanol Sin, (02): 221–229 Yu Y, Wang YB, Fan WF, Dong JW, Wang HB, Yuan ZW, Geng L, Du YF, Li YF (2024) SEDIMENTARY ENVIRONMENT AND MEIOFAUNA COMMUNITY STRUCTURE IN RIVER-SEA INTERACTION AREA OFF CHAOSHAN. GUANGDONG Mar Lakes 55(01):155–170 (in Chinese) Yang CY, Zhang LH, Du YF, Wu YP, Zhang AG, Yuan XT (2020) MEIOFAUNAL COMMUNITY IN SANDY INTERTIDAL ZONE AND ITS ENVIRONMENTAL RESPONSE IN SHUANGTAIZI ESTUARY, NE CHINA. Ocean Lakes 51(03):572–582 (in Chinese) Yuan C (2017) Distribution of meiofauna and its correlation with main environmental factors in Dongzhai port Mangrove of Hainan province. Hainan University. (in Chinese) Zhou H, Zeng R, Wang Y (2025) Large-scale pattern of metazoan meiofauna as descriptor of environmental gradient along the shelf seas of China. 84(000). Regional Studies in Marine Science10.1016/j.rsma.2025.104075 Zhu L, Chen C, Yang XJ, Cui XJ, Shao CC, Teng AK, Yu ZS (2024) Study on the abundance, biomass and environmental factors of meiofauna in Jiaozhou Bay. Periodical Ocean Univ China 54(4):69–77. 10.16441/j.cnki.hdxb.20220169 (in Chinese) Zhu JY (2023) Research on the Changes of Resource Environment in the Nearshore Waters of Rudong Under the Influence of Coastal Development. Nanjing Normal Univ. 10.27245/d.cnki.gnjsu.2023.003822 (in Chinese) Zhang YC (2022) Characteristics and suitability of benthic community in a typical river section from Fuling to Fengdu in the upper Yangtze River. 10.27671/d.cnki.gcjtc.2022.001023 . (in Chinese) Zhang Y, Zhang ZN, Hua E (2009) Relationship between Distribution of Meiofauna and Environmental Factors in Southern Yellow Sea. Chin Agric Sci Bull 25(19):323–329 (in Chinese) Zhang Y (2009) A Study on Seasonal Variation of Abundance and Biomass of Meiofauna at the Typical Station in Jiaozhou Bay. Chin Agric Sci Bull 25(17):296–301 (in Chinese) Zou LZ (2006) Study on meiofauna and deep-sea sediment 18S rDNA gene diversity in China Contract Area. Third Institute of Oceanography, State Oceanic Administration. (in Chinese) Zhang Y (2006) Studies on community structure and biodiversity of meiofauna in the Southern Yellow Sea, China. Ocean University of China. (in Chinese) Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 18 May, 2026 Reviewers invited by journal 01 May, 2026 Editor assigned by journal 01 May, 2026 Submission checks completed at journal 30 Apr, 2026 First submitted to journal 27 Apr, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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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-9542365","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":637369951,"identity":"e59acc6b-1eaa-45f8-9121-3a456c460358","order_by":0,"name":"Yongcun Zhao","email":"","orcid":"","institution":"Ocean College of Hebei Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Yongcun","middleName":"","lastName":"Zhao","suffix":""},{"id":637369952,"identity":"972deae1-2e99-42f0-a4fc-22cca6417921","order_by":1,"name":"Jianxia Liu","email":"","orcid":"","institution":"Ocean College of Hebei Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Jianxia","middleName":"","lastName":"Liu","suffix":""},{"id":637369953,"identity":"bef19323-2355-4228-8a5e-0f2df61f4110","order_by":2,"name":"Futang Ma","email":"","orcid":"","institution":"Ocean College of Hebei Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Futang","middleName":"","lastName":"Ma","suffix":""},{"id":637369954,"identity":"2e185f77-4232-42e3-b068-9e8eceb62006","order_by":3,"name":"Zhe Pan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAvklEQVRIiWNgGAWjYBACPuYDIOoAAz8z8+EHRGlhY0uAaJFsZ0szIE2LwXkeBQkitfAe/Fzw546c8WEeBgOGGptoIrTwJUvP4HlmbHaY98ADhmNpuQ0Etcj3GEjzSBxO3HaYL8GAseEwEVrYeIx/8xgcrt/czGMgQawWM2mehMMJBszEa+FLs+Y5cNhwxmFgICcQ4xd+Nt7Dt3n+HJbn7z98+MGHGhvCWhgYeJDYCYSVo2sZBaNgFIyCUYANAABOtjgOQqNziAAAAABJRU5ErkJggg==","orcid":"","institution":"Ocean College of Hebei Agricultural University","correspondingAuthor":true,"prefix":"","firstName":"Zhe","middleName":"","lastName":"Pan","suffix":""},{"id":637369955,"identity":"1c4fe269-3298-4eb2-b27b-d9570c00a40d","order_by":4,"name":"Yingkun Cao","email":"","orcid":"","institution":"Ocean College of Hebei Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Yingkun","middleName":"","lastName":"Cao","suffix":""}],"badges":[],"createdAt":"2026-04-27 13:23:52","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9542365/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9542365/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":109090658,"identity":"0e784bb0-46ca-43fd-bdce-2baecda4b4b5","added_by":"auto","created_at":"2026-05-12 13:33:29","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":4126100,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic Diagram of Sampling Stations in Huanghua Port\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9542365/v1/1d7d2fbfa4bbe664bb010c84.jpeg"},{"id":109090610,"identity":"8735d106-63bc-4acb-8241-b4bb31cb2e00","added_by":"auto","created_at":"2026-05-12 13:33:03","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":138423,"visible":true,"origin":"","legend":"\u003cp\u003eAbundance of meiofauna at the two stations.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-9542365/v1/f94db8e2ad29b60b51a5d36d.png"},{"id":109091049,"identity":"77d244e7-f4ba-4644-9f0a-6198a38c3dea","added_by":"auto","created_at":"2026-05-12 13:35:11","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":907950,"visible":true,"origin":"","legend":"\u003cp\u003ePrincipal Component Analysis (PCA) of Environmental Factors at Survey Stations in Huanghua Port\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-9542365/v1/1ab8b5e0d7a543f97a67036a.png"},{"id":109093635,"identity":"d0cffaa3-caff-403e-b83a-38f516cf0220","added_by":"auto","created_at":"2026-05-12 13:47:47","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":5537883,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9542365/v1/76abafa6-5ddf-464c-ab78-d101a9c827b1.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Community Structure of Meiofauna and Its Environmental Drivers in Huanghua Port, Bohai Bay","fulltext":[{"header":"Introduction","content":"\u003cp\u003eAs the intensity of coastal development continues to increase, marine ecological environment issues are becoming increasingly prominent. Human activities such as nearshore aquaculture and industrial wastewater discharge have already had a significant impact on the marine ecosystem (Schratzberger et al.,2018), leading to water quality deterioration, habitat degradation, and a decline in biodiversity. Huanghua Port is located in a silty\u0026ndash;mud coastal zone of the Bohai Bay (Bao et al.,2026). Influenced by river inputs and marine dynamics, the sedimentary environment is complex and nutrient-rich, with abundant plankton and meiofauna (Gao et al.,2015). However, with the industrialization of coastal cities and the discharge of large amounts of pollutants into the sea, conducting research on the ecological environment and biological community characteristics of this sea area is of great significance for understanding the regional ecological status and its trends. In 1942, Mare first referred to a type of sessile benthic invertebrates smaller than large benthic animals as \"Meiofauna\" (i.e., Meiofauna) (Hong et al.,2025). Meiofauna are defined as metazoans that pass through a 500 \u0026micro;m sieve but are retained by a 42 \u0026micro;m or 31 \u0026micro;m mesh sieve (Zhu et al.,2022; Zhou et al.,2025; Zhu et al.,2023; Zhang et al.,2022). They include both permanent and temporary benthic organisms (Chu et al.,2022). Meiofauna, as an important component of marine benthic ecosystems, serve as a food source for the larvae of many fish, shrimp, and mollusks, and play a regulatory role in the production and consumption of microorganisms and bacteria (Cai, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). They primarily feed on detritus and heterotrophic bacteria in the seabed sediments (Zou,2006), and are an indispensable part of the coupling process of benthic ecosystems in the water column, play a key role in benthic food webs and nutrient cycling (Ecology, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Due to their short life cycles and sensitivity to environmental changes, studies have shown that meiofauna can serve as important biological indicators of environmental pollution and climate change (Coull et al.,1988; Zhang et al.,2019; Marine,2018; Higgins,2020). Therefore, conducting ecological environment assessments based on the characteristics of small benthic communities holds significant research value.\u003c/p\u003e \u003cp\u003eCurrently, research on Meiofauna in the waters of Huanghua Port is still relatively limited, especially in the context of port development and human activities, where systematic analysis of their community structure and environmental response characteristics is still lacking. In recent years, with the continuous strengthening of aquaculture activities and port development, the regional water bodies and sedimentary environments have been constantly changing, which may have significant impacts on the benthic community. Therefore, research in the waters near Huanghua Port remains limited and requires further investigation. This study collected sediment samples from two different sites near Huanghua Port to explore the community structure, biomass, and their relationships with environmental factors of Meiofauna in the vicinity of Huanghua Port. The aim is to observe the water quality and pollution levels in the waters near Huanghua Port, providing scientific data support for the assessment of fishery resources and environmental conditions in the Bohai Bay near Huanghua Port.\u003c/p\u003e"},{"header":"Materials \u0026 Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSampling Time and Location\u003c/h2\u003e \u003cp\u003eThis study set up two sampling stations near Huanghua Port in the Bohai Bay area in May 2018 to conduct the investigation. Station 1: 38°21.032'N, 117°56.317'E, Station 2: 38°31′58.8″N, 118°7′12″E. (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e), each station was set up with 3 replicate samples, totaling 6 undisturbed sediment samples collected.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSample Collection Methods and Laboratory Analysis\u003c/h3\u003e\n\u003cp\u003eOnsite, a QNC6 stainless steel grab sampler was used to collect sediment samples. Under undisturbed conditions, a sampling tube with an inner diameter of 2.6 cm was used to randomly collect core samples (depth 8 cm), which were then bottled in layers according to 0–2 cm, 2–5 cm, and 5–8 cm. A suitable amount of 10% formaldehyde solution was added for fixation and preservation, to be used for the analysis of meiofauna. Additionally, some sediment samples were sealed and frozen at -20°C for the measurement of environmental factors. Environmental parameters were measured using a YSI probe some environmental factors on-site, including water temperature (Temp), pH, salinity (Salinity). The turbidity used the Secchi disk method. Water depth was obtained using a shipboard sensor.\u003c/p\u003e \u003cp\u003eIn the laboratory, after thawing the samples, 5 ml of Bengal rose dye was added and left to stain for 24 hours. The meiofauna were then sorted using a double-layer sieve with mesh sizes of 500 µm and 42 µm (Qiao et al.,2021). The Meiofauna were separated using the Ludox-TM centrifugation method, repeated three times. Samples were transferred to Petri dishes for classification, identification, and counting under a stereomicroscope, and preserve the samples in 75% alcohol for future use.\u003c/p\u003e \u003cp\u003eGiven that the sediment in the waters near Huanghua Port is primarily silt, this study employed the flotation sedimentation method for sample washing and sorting. The experimental treatment and data statistical methods were the same as those used by Qiao Chunyan et al. (Kosmala et al.,2026). Nitrite (NO₂\u003csup\u003e⁻\u003c/sup\u003e), ammonia nitrogen (NH₃-N), nitrate (NO\u003csub\u003e3\u003c/sub\u003e\u003csup\u003e⁻\u003c/sup\u003e), soluble phosphate (SRP), and reactive silicate (SiO₃-Si) were determined according to the \"Marine Monitoring Specification Part 4\" (GB 17378.4–2007), using the naphthyl ethylenediamine spectrophotometric method, hypobromite oxidation method, cadmium column reduction method, molybdenum blue spectrophotometric method, and silicomolybdenum blue spectrophotometric method, respectively. The abundance ratio of nematodes to copepods (N/C) is usually used as a reference indicator for the environment. An N/C \u0026lt; 50 indicates that the sediment environment is normal; 50 \u0026lt; N/C \u0026lt; 100 indicates that the sediment environment is eutrophic; and N/C \u0026gt; 100 indicates the presence of organic pollution in the sediment (Gordillo et al.,2025).\u003c/p\u003e\n\u003ch3\u003eData Management and Analysis\u003c/h3\u003e\n\u003cp\u003eArcGIS was used to create station maps. To study the relationship between environmental factors and benthic organisms, Origin was used to plot the distribution map of meiofauna abundance. Using SPSS 31.0 software, the data were subjected to normality tests, and one-way ANOVA was employed to compare the differences in the abundance of Meiofauna at different stations. Pearson correlation analysis was used to explore the relationship between the abundance of major groups and environmental factors, with a significance level set at \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05. In addition, the PRIMER 6.0 software was used to calculate the community diversity index and perform multivariate analysis to reveal the relationship between the structure of meiofauna communities and environmental factors (Ingels et al.,2011).\u003c/p\u003e"},{"header":"Research Results","content":"\u003ch2\u003eComposition, Abundance, and Biomass of Different Benthic Invertebrate Groups at Different Stations\u003c/h2\u003e\u003cp\u003eMeiofaunal communities consisted mainly of Meiofauna in the waters of Huanghua Port in the Bohai Bay, four main groups of meiofauna were identified: free-living marine nematodes (Nematoda), benthic copepods (Copepoda), ostracods (Ostracoda), and polychaetes (Polychaeta). The remaining groups were classified as \"other groups.\" Overall, free-living marine nematodes are the dominant group, accounting for 70.8% of the total abundance of meiofauna, followed by benthic copepods, ostracods, and polychaetes. The abundance of meiofauna varied among stations (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). At Station 1, the abundance of free-living marine nematodes was 182.16 ± 10.97 ind./10 cm², benthic copepods were 47.11 ± 13.53 ind./10 cm², ostracods were 35.18 ± 12.50 ind./10 cm², polychaetes were 8.17 ± 0.58 ind./10 cm², and other groups were 5.65 ± 1 ind./10 cm²; at Station 2, the abundance of free-living marine nematodes was 140.71 ± 4.04 ind./10 cm², benthic copepods were 32.04 ± 1.73 ind./10 cm², ostracods were 6.91 ± 2.08 ind./10 cm², polychaetes were 3.77 ± 0 ind./10 cm², and other groups were 6.91 ± 1.54 ind./10 cm². Overall, the abundance of various groups at Station 1 is higher than at Station 2.\u003c/p\u003e\u003cp\u003eBy comparing experimental data, free-living marine nematodes were found to be the dominant population at both sampling sites, followed by benthic copepods. Further analysis revealed that although the composition of meiofauna communities at the two sampling sites near Huanghua Port was similar, there were differences in biological abundance. This was due to variations in other environmental factors such as water depth, temperature, sediment organic matter content, and transparency.\u003c/p\u003e\u003cp\u003e \u003c/p\u003e\u003ch2\u003eThe Ratio of Nematodes to Copepods Abundance (N/C) at Different Stations\u003c/h2\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\"\u003e\u003c/div\u003e\u003ctable id=\"Tab1\" border=\"1\"\u003e \u003ccaption\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eN/C values of Meiofauna at different stations\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003c/colgroup\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\"\u003e \u003cp\u003eAbundance\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eStation 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eStation 2\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNematodes(ind./10 cm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003e140.71 ± 4.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003e182.16 ± 10.97\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eBenthos copepods(ind./10 cm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003e32.04 ± 1.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003e47.11 ± 13.53\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eN/C\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003e4.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\"\u003e \u003cp\u003e3.87\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/table\u003e\u003c/div\u003e\u003cp\u003eThe two main groups of meiofauna (nematodes and copepods) exhibit certain differences in their tolerance to environmental disturbances and organic pollution. Copepods have a lower tolerance to organic pollution, while nematodes have a higher tolerance, allowing them to have greater abundance in waters with organic pollution. Therefore, by comparing the abundance ratio of free-living marine nematodes to benthic copepods at two sites, we can infer whether the waters near Huanghua Port are affected by organic pollution and assess the overall ecological condition. The N/C value at Huanghua Port (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e) shows that the abundance of free-living marine nematodes and benthic copepods are 182.16 ± 10.97 ind./10 cm² and 47.11 ± 13.53 ind./10 cm², respectively, corresponding to an N/C value of 3.87. At Station 2, the abundances are 140.71 ± 4.04 ind./10 cm² and 32.04 ± 1.73 ind./10 cm², respectively, corresponding to an N/C value of 4.39. In the comparison of N/C ratios at different stations, results showed that the N/C value at station 1, which is closer to the coast, is relatively higher, while the N/C value at station 2, which is farther from the coast, is lower. This pattern may be attributed to the geographical location of the stations. Station 1, being closer to the estuary and near the industrial discharge area, has a relatively higher organic matter content, which in turn affects the N/C ratio. In contrast, Station 2 is far from these potential pollution sources, has lower organic matter content, and therefore a relatively lower N/C ratio. However, overall, the sedimentary environments at both sites are relatively good.\u003c/p\u003e\u003ch3\u003eThe Correlation Between the Abundance of Meiofauna and Environmental Factors\u003c/h3\u003e\u003cp\u003eThis study analyzes the correlation between the abundance of major groups of Meiofauna and environmental factors thru correlation analysis, presenting the results of their association (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003ctable id=\"Tab2\" border=\"1\"\u003e \u003ccaption\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCorrelations between the abundance of meiofauna in the Yellow and Bohai Seas and environmental factors.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003c/colgroup\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" rowspan=\"2\"\u003e \u003cp\u003eDepth\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eNematodes\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eCopepods\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003ePolychaetes\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eAmphipods\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eOther\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eN/C ratio\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\"\u003e \u003cp\u003e-0.974*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e-0.657\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e-0.996*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e0.974*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e0.759\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e0.999*\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eTemp\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.044\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.726\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.309\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.408\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.345\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.256\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.964*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.679\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.997*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.979*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.771\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.998*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eSDD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.977*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.651\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.996*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.972*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.758\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.999*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNO₂\u003csup\u003e⁻\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.490\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.455\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.528\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.527\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.066\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.510\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNH₃-N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.592\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.228\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.376\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.264\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.208\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.424\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eT-NO₂\u003csup\u003e⁻\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.560\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.391\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.296\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.173\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.311\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.362\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNO₃\u003csup\u003e⁻\u003c/sup\u003e-N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.445\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.991*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.675\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.773\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.190\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.615\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eSRP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.295\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.408\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.427\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.437\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.787\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.419\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eSiO₃-Si\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.524\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.388\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.275\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.147\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.248\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.335\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003eNote: *Correlation is significant at the 0.05 level.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e\u003cp\u003eOverall, depth (Depth), salinity (S), transparency (SDD), and N/C ratio have a significant correlation with the structure of meiofauna communities, while factors such as Temp, NO₂\u003csup\u003e⁻\u003c/sup\u003e, NH₃-N, NO3\u003csup\u003e⁻\u003c/sup\u003e, SRP, and SiO₃-Si do not show a significant correlation with the abundance of most groups.\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" class=\"colspec\"\u003e\u003c/div\u003e\u003ctable id=\"Tab3\" border=\"1\"\u003e \u003ccaption\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eRelationship between variables of meiofauna in the Yellow and Bohai Seas and environmental factors.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"11\"\u003e \u003c/colgroup\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" rowspan=\"2\"\u003e \u003cp\u003eDepth\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eNematodes\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eCopepods\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003ePolychaetes\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eAmphipods\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eOther\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eN/C ratio\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003eS\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003ed\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e\u003cem\u003eJ’\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e\u003cem\u003eH′\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\"\u003e \u003cp\u003e-0.974*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e-0.657\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e-0.996*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e-0.974*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e0.759\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e0.999*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e0.289\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e0.272\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e0.237\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\"\u003e \u003cp\u003e0.281\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eTemp\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.044\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.726\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.309\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.408\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.345\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.256\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.845\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.816\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.968*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.921*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.964*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.679\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.997*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.979*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.771\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.998*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.322\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.304\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.279\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.319\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eSDD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.977*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.651\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.996*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.972*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.758\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.999*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.279\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.262\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.226\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.270\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNO₂\u003csup\u003e⁻\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.490\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.455\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.528\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.527\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.066\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.510\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.345\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.356\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.259\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.305\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNH₃-N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.592\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.228\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.376\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.264\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.208\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.424\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.714\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.712\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.770\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.744\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eT-NO₂\u003csup\u003e⁻\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.560\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.391\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.296\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.173\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.311\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.362\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.482\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.469\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.649\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.563\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eNO₃\u003csup\u003e⁻\u003c/sup\u003e-N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.445\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.991*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.675\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.773\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.190\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.615\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.597\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.594\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.583\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.598\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eSRP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.295\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.408\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.427\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.437\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.787\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.419\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.597\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.543\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.782\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.712\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\"\u003e \u003cp\u003eSiO₃-Si\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.524\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.388\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.275\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.147\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.248\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e0.335\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.750\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.751\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.791\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\"\u003e \u003cp\u003e-0.772\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"11\"\u003eNote: *Correlation is significant at the 0.05 level.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e\u003cp\u003eSpecifically, the abundance of the three dominant groups—nematodes, polychaetes, and ostracods—exhibits highly similar environmental response patterns: the abundance of all three is significantly negatively correlated with depth and transparency (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05) and significantly positively correlated with salinity (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05). The environmental correlation of benthic copepods shows a significant difference compared with the aforementioned three dominant groups. Their abundance is only significantly positively correlated with the concentration of nitrate (NO₃\u003csup\u003e⁻\u003c/sup\u003e-N) (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05) and shows no significant correlation with depth, salinity, SDD, and other environmental factors. This result indicates that nitrate may be the key environmental factor regulating the abundance of copepods. The abundance of other groups did not show significant correlations with any environmental factors (\u003cem\u003ep\u003c/em\u003e \u0026gt; 0.05), indicating that their distribution is less influenced by the environmental factors monitored in this study and is more significantly affected by other unmonitored factors (food resources, substrate type, biological disturbances, etc.). The N/C ratio is significantly positively correlated with depth and SDD (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05), and significantly negatively correlated with salinity (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05). This indicates that with increasing water depth, higher transparency, and lower salinity, the N/C ratio of Meiofauna in the water body will significantly increase. This result also confirms the impact of differences in organic matter input and pollution levels between different sites on the aquatic environment and meiofauna (Cao et al.,2015).\u003c/p\u003e\u003cp\u003eOverall, the community structure of Meiofauna is influenced by various environmental factors, and the best combination of environmental factors to explain the community structure is depth, transparency, and salinity.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eMeiofaunal abundance and community composition\u003c/h2\u003e \u003cp\u003eThe present study shows that meiofaunal communities in the nearshore waters of Huanghua Port are dominated by nematodes, which accounted for more than 70% of the total abundance. This dominance pattern is consistent with previous studies conducted in coastal and estuarine ecosystems in China, where nematodes typically represent the most abundant meiofaunal group (Li et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2022\u003c/span\u003e; Kim et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2025\u003c/span\u003e; Cao et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). The ecological success of nematodes is generally attributed to their high tolerance to environmental stress, short life cycles, and broad feeding strategies, which allow them to adapt to fluctuating and disturbed habitats (Coull, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e1988\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eHowever, the overall abundance of meiofauna in Huanghua Port was relatively low compared with other coastal regions such as the Yangtze River estuary and the Tangshan Sandao area (Zhang et al., 2006; Cao et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). This difference may be explained by the relatively unstable sediment conditions and strong hydrodynamic disturbance in the study area. Shallow coastal environments influenced by port activities and sediment resuspension often exhibit reduced habitat stability, which can limit meiofaunal colonization and reduce overall abundance.\u003c/p\u003e \u003cp\u003eIn addition, the relatively simple community composition observed in this study, with only a few dominant taxa, suggests a degree of environmental disturbance. Previous studies have shown that simplified community structures and dominance of tolerant taxa are typical features of disturbed coastal ecosystems (Schratzberger and Somerfield, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Therefore, the meiofaunal community in Huanghua Port likely reflects the combined effects of natural environmental variability and anthropogenic disturbance.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u003cb\u003ec\u003c/b\u003eomparison of Meiofaunal Abundance in This Study with Those in Other Sea Areas\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" 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=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStudy area\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSampling time\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAbundance ind./10cm\u0026sup2;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eProportion of nematodes\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eRef.\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHuanghua Port coastal waters\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2018.May\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e228.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e70.8%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ethis study\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTangshan Sandao sea area\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2013.May. Aug. Oct\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e735.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;95%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eLi et al.,2022\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYangtze River Estuary and Adjacent Continental Shelf Sea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2006.Jul-Aug\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e453.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e81.37%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eKim et al.,2025\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQinhuangdao coastal waters\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2013.May. Sep. Oct\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e695.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e93.01%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCao et al.,2018\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eEnvironmental drivers of meiofaunal distribution\u003c/h2\u003e \u003cp\u003eThis study identified water depth, salinity, and transparency as the primary environmental factors influencing meiofaunal community structure, which is consistent with findings from other coastal regions (Mao et al., \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Yang et al., \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Yu et al., \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). These factors influence meiofaunal distribution through their effects on sediment characteristics, food availability, and habitat stability.\u003c/p\u003e \u003cp\u003eThe negative relationship between meiofaunal abundance and water depth observed in this study may be related to reduced organic matter input and lower biological activity in deeper waters. Shallow areas typically receive higher inputs of organic detritus and experience stronger benthic\u0026ndash;pelagic coupling, which enhances food availability for meiofauna (Zhang et al., \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Similarly, the negative correlation with transparency suggests that areas with higher suspended particles and organic matter may provide more favorable feeding conditions for detritivorous organisms.\u003c/p\u003e \u003cp\u003eSalinity showed a significant positive correlation with the abundance of several dominant groups, indicating that relatively stable marine conditions favor meiofaunal development. In estuarine environments, fluctuations in salinity can impose physiological stress on benthic organisms, whereas stable salinity conditions promote community stability and diversity (Cai et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2002\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn contrast to other groups, copepods showed a significant positive correlation only with nitrate concentration, suggesting that their distribution is more strongly influenced by nutrient availability than by physical environmental factors. This finding reflects differences in ecological niches and feeding strategies among meiofaunal taxa. Copepods are often more sensitive to food quality and nutrient conditions, which may explain their distinct response pattern.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eN/C ratio and environmental assessment\u003c/h2\u003e \u003cp\u003eThe nematode-to-copepod ratio (N/C) has been widely used as an indicator of environmental quality due to the contrasting responses of these two groups to organic pollution (Raffaelli et al., 2009). In this study, N/C values ranged from 3.87 to 4.39, which are well below the threshold values typically associated with organic pollution. This suggests that the sedimentary environment in Huanghua Port is relatively unpolluted.\u003c/p\u003e \u003cp\u003eHowever, the interpretation of the N/C ratio should be approached with caution. Several studies have highlighted that this index can be influenced by multiple factors, including sediment type, hydrodynamic conditions, and species-specific ecological traits (Hao et al., 2022). For example, nematodes are known to tolerate organic enrichment, while copepods are more sensitive and tend to decline under polluted conditions. Nevertheless, variations in substrate type and habitat structure may also affect their relative abundance.\u003c/p\u003e \u003cp\u003eThe slightly higher N/C ratio observed at the nearshore station may reflect increased organic input associated with human activities such as aquaculture and industrial discharge. In contrast, the offshore station, which is less influenced by anthropogenic inputs, exhibited lower N/C values. Similar spatial patterns have been reported in other coastal systems, where nearshore areas are more affected by organic enrichment (Cao et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2015\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDespite its usefulness, the N/C ratio alone may not fully capture the complexity of benthic environmental conditions, particularly at small spatial scales (Subhra et al.,2023; Katlyn et al.,2023). Therefore, it is recommended that this index be used in combination with other biological and environmental indicators to provide a more comprehensive assessment of ecosystem health (L\u0026uuml;,2025).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eImplications for coastal ecosystem management\u003c/h2\u003e \u003cp\u003eThe results of this study indicate that meiofaunal communities in Huanghua Port are shaped by both environmental gradients and human activities (\u0026Eacute;lise et al.,2020). The dominance of tolerant taxa and relatively low diversity suggest that the ecosystem is subject to a certain level of disturbance, although not severely polluted (Environmental,2020; Hual and Liu Xiaoshu,2024).\u003c/p\u003e \u003cp\u003eMeiofauna can serve as effective bioindicators due to their rapid response to environmental changes, low sampling cost, and minimal environmental impact during monitoring (Sautya et al., \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Therefore, incorporating meiofaunal analysis into routine ecological monitoring programs could improve the assessment of coastal environmental quality.\u003c/p\u003e \u003cp\u003eOverall, this study provides important baseline data for understanding the ecological status of Huanghua Port and highlights the need for continued monitoring under increasing anthropogenic pressure. Future studies should expand spatial and temporal sampling to better capture variability and improve the reliability of ecological assessments.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eBased on the survey data from the nearshore waters of Huanghua Port in May 2018, this study analyzed the community structure characteristics of meiofauna and their relationship with environmental factors. The results indicate that a total of five groups of meiofauna were identified, with marine nematodes being the dominant group. The community composition was simple, primarily consisting of pollution-tolerant types, reflecting the impact of the disturbed nearshore environment. Abundance shows significant spatial differentiation: nearshore stations are higher than offshore stations, and overall abundance is lower than that in Jiaozhou Bay. Water depth, salinity, and transparency are the main environmental factors regulating community structure. The abundance of nematodes, polychaetes, and ostracods exhibited consistent response trends, showing a significant negative correlation with water depth and transparency (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05), and a significant positive correlation with salinity (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). In contrast, the abundance of benthic copepods was only significantly positively correlated with nitrate (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05), indicating ecological differentiation in the response of different groups to environmental factors. The N/C ratio at the two stations indicates that the ecological environment of this sea area is good. In summary, the structure of the benthic macrofauna community in the nearshore waters of Huanghua Port is jointly influenced by environmental factors and human activities. The characteristics of this community can serve as effective indicators for regional ecological environment assessment and provide fundamental data support for ecological monitoring and restoration in this area.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis study was supported by the National Natural Science Foundation of China (Youth Fund Project) (No. 32503188) and the Scientific Research Project of Higher Education Institutions in Hebei Province (No. QN2026778).\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eZ is responsible for writing the article, data analysis, and creating images. L and M are in charge of sampling and conducting experiments, obtaining experimental results, and checking the article format. P and C guide the experiments and provide technical support.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThis study was supported by the National Natural Science Foundation of China (Youth Fund Project) (No. 32503188) and the Scientific Research Project of Higher Education Institutions in Hebei Province (No. QN2026778).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBao JJ, He YY, Liu XS (2026) Spatial and temporal distribution of meiofauna and the influencing environmental factors in Jiaozhou Bay. 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(in Chinese)\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":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"thalassas-an-international-journal-of-marine-sciences","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"thal","sideBox":"Learn more about [Thalassas: An International Journal of Marine Sciences](http://link.springer.com/journal/41208)","snPcode":"41208","submissionUrl":"https://submission.nature.com/new-submission/41208/3","title":"Thalassas: An International Journal of Marine Sciences","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Huanghua Port, Meiofauna, Community, structure, Environmental drivers, Coastal ecosystem","lastPublishedDoi":"10.21203/rs.3.rs-9542365/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9542365/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study investigated the community structure of meiofauna and its environmental drivers in the nearshore waters of Huanghua Port (Bohai Bay) based on field sampling conducted at two stations in May 2018. Meiofaunal assemblages were dominated by free-living nematodes, followed by copepods, ostracods, and polychaetes. The mean abundance of meiofauna was 161.44\u0026thinsp;\u0026plusmn;\u0026thinsp;7.51 ind./10 cm\u0026sup2;, with nematodes accounting for 70.8% of the total abundance. Meiofaunal abundance differed between stations, with higher values observed at the nearshore site. Statistical analysis revealed that water depth, salinity, and transparency were identified as the primary environmental drivers influencing community structure. The abundances of nematodes, polychaetes, and ostracods were significantly negatively correlated with water depth and transparency (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05), and positively correlated with salinity (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). In contrast, copepod abundance was significantly correlated only with nitrate concentration (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). The nematode-to-copepod ratio (N/C) ranged from 3.87 to 4.39, indicating relatively low levels of organic pollution in the study area. However, given the limited spatial scale of sampling, this indicator should be interpreted with caution. Overall, this study provides baseline data on meiofaunal community structure and its environmental responses in Huanghua Port, contributing to ecological assessment and coastal management.\u003c/p\u003e","manuscriptTitle":"Community Structure of Meiofauna and Its Environmental Drivers in Huanghua Port, Bohai Bay","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-12 13:06:19","doi":"10.21203/rs.3.rs-9542365/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"173985062596324967013435885710698052336","date":"2026-05-18T06:34:39+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-05-01T12:32:10+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-05-01T12:31:05+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-05-01T03:02:56+00:00","index":"","fulltext":""},{"type":"submitted","content":"Thalassas: An International Journal of Marine Sciences","date":"2026-04-27T13:08:24+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"thalassas-an-international-journal-of-marine-sciences","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"thal","sideBox":"Learn more about [Thalassas: An International Journal of Marine Sciences](http://link.springer.com/journal/41208)","snPcode":"41208","submissionUrl":"https://submission.nature.com/new-submission/41208/3","title":"Thalassas: An International Journal of Marine Sciences","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"52648b6d-9e59-43a6-a77b-5d9889379b45","owner":[],"postedDate":"May 12th, 2026","published":true,"recentEditorialEvents":[{"type":"reviewerAgreed","content":"173985062596324967013435885710698052336","date":"2026-05-18T06:34:39+00:00","index":25,"fulltext":""},{"type":"reviewersInvited","content":"13","date":"2026-05-01T12:32:10+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-05-01T12:31:05+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-05-01T03:02:56+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-12T13:06:19+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-12 13:06:19","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9542365","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9542365","identity":"rs-9542365","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}