Developing a palaeoceanographic proxy based on the dimensions of Adercotryma glomeratum populations: a case study in Drake Passage region (Antarctic Peninsula)

Developing a palaeoceanographic proxy based on the dimensions of Adercotryma glomeratum populations: a case study in Drake Passage region (Antarctic Peninsula) | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Developing a palaeoceanographic proxy based on the dimensions of Adercotryma glomeratum populations: a case study in Drake Passage region (Antarctic Peninsula) Camila Cunha PASSOS, Maria Virginia ALVES MARTINS, Wânia Duleba This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4578446/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 17 Jan, 2025 Read the published version in Journal of Sedimentary Environments → Version 1 posted 9 You are reading this latest preprint version Abstract The Drake Passage is a highly hydrodynamic region that is difficult to navigate due to adverse weather conditions and intense surface currents. This study investigates how the bottom hydrodynamic regime influences the size of foraminiferal tests on the Antarctic Peninsula. For this, the species Adercotryma glomeratum (an agglutinated species of foraminifera) was chosen, as it was the only species abundant in the seven selected stations. Five stations (EB-1 to EB-5) are located in a region with a depth of ~ 480 m and two in a deep area of ~ 3,800 m (DK-1 and DK-2). All the tests were individually measured along their long axis and classified according to size. The most frequently recorded size range of A. glomeratum varied between ≈ 90–180 µm. The average test size and standard deviation were lower at stations EB-1 to EB-5, with coarser-grained sediments. The cluster analysis based on grain size, morphometric data of A. glomeratum , and depth shows that the largest sizes of this species tend to occur in fine-grained sediments at stations DK-1 and DK-2. The fine-grained sediments at stations DK-1 and DK-2 indicate the presence of calmer bottom conditions. These results suggest that in deep-sea environments, the stable areas, under calmer hydrodynamic conditions, enable longer life cycles of living foraminifera and the development of populations with bigger individuals, namely of A. glomeratum. The data obtained in this work suggest that the size of A. glomeratum populations can be used as an indicator of the stability/instability of the environment. Thus, the size of the individuals that make up the populations of A. glomeratum , and probably other foraminiferal species, can be used in paleoenvironmental reconstructions as a trace of disturbances or environmental stability in deep-sea settings, such as that of the Southern Ocean. Sediment Benthic Foraminifera Living populations Deep Sea Bio-indicator Figures Figure 1 Figure 2 Figure 3 Figure 4 1. Introduction There is still much to discover about the impacts that highly dynamic environments have on benthic marine organisms (Bernhard et al., 2009) in offshore environments, directly influenced by the characteristics of the bottom water bodies and the nutrient supply of the sea surface. The Southern Ocean is a unique environment, as it is the origin of several water bodies that move around the planet by thermohaline circulation (Robertson et al. 2011). With the Drake Passage (DP) opening, the Antarctic Peninsula (AP) can be considered the main obstacle encountered by the Antarctic Circumpolar Current (ACC), with great importance in the region, as it is the only current that links the Atlantic, Indian, and Pacific Oceans (Joughin and Alley, 2011). Despite its particular conditions, the factors that condition the characteristics of the living communities of the Southern Ocean are still poorly understood, particularly those that condition benthic meiofaunal organisms, such as foraminifera. Benthic foraminifera can respond quickly in different ways to environmental variations (Wollenburg and Kuhnt, 2000; Boltovskoy et al. 1991; Jones 2013 , Amao et al. 2020). The use of these organisms to assess impacted areas as indicators of pollution, for example, is frequent, as they can answer to variations in physicochemical characteristics of the environment in which they live (Scott et al. 2001; Bouchet et al., 2009; Cesbron et al., 2016). Their answers include changes in abundance, assemblage composition (Jauffrais et al., 2016; Amao et al., 2020), and morphological modifications (Boltovskoy et al., 1991; Yanko et al., 1998; Stefanoudis et al., 2016; El-Kahawy et al., 2018 ), such as changes in coiling direction, size of the aperture and size, thickness and color of the chamber/s and the test size (Ishman and Domack, 2004 ; Murray, 2006 ), as well as changes in the chemical composition of the test wall, depending on the water composition. For this reason, they are also used to trace palaeoceanographic and paleoclimatic evolution. However, little is known about the morphological changes of benthic foraminifera in the deep-sea. In extreme environments like Antarctica, the benthic community is subjected to natural environmental stress that often limits the survival of many organisms, such as low temperatures, the presence of corrosive waters, limited food, and dissolved oxygen in the sediment. Because it is a highly dynamic region with unique geological characteristics, AP has a wide range of environments (Finger and Lipps, 1981 ; Mackensen et al., 1990; Milkov, 2000 ; Rodrigues et al., 2013). The DP is a region of difficult navigability, with adverse climatic conditions and intense surface currents; therefore, works with the recovery of marine sediments are pretty scarce (Santini, 2011 ), especially of benthic foraminifera. Therefore, this study intends to investigate the influence of the bottom hydrodynamic regime and depth on the dimensions of benthic foraminifera populations in deep-sea settings off the Antarctic Peninsula. To achieve this objective, seven stations located between the Bransfield Strait and the DP were selected (Fig. 1 ). This work is essential given the limited knowledge about benthic foraminifera in the DP region and the small number of studies that address morphometric studies of benthic foraminifera in deep-sea environments. Some studies have used granulometric ranges from which the organisms are picked, identified, and counted, and their dimensions are assumed to fall within those ranges (Ernst et al., 2006; Frontalini and Coccioni, 2008; Martins et al., 2016 ). Most of these works are related to species with carbonated tests and in monitoring studies of coastal regions under high anthropic influence (Alve et al., 1995; Le Cadre and Debenay, 2006). This work also aims to develop a proxy indicator of stability/instability of the conditions prevailing in the deep-sea based on the size of foraminifera, which can be applied in paleoenvironmental reconstructions. 2. Study area The DP is located in the Scotia Sea basin, between South America and the Antarctic Peninsula (Fig. 1 ). On average, the central and western portions are deeper, with about 3000 m, and less hilly or flat (Thorpe, 2002 ). The region is affected by different and overlapping tectonic regimes, where one plate is subjected to subduction and the other is associated with a tectonic fault (Solovyov et al., 2011). The southern portion of the DP has diversified morphology, which includes: 1) the Shackleton Transversal Chain (STC), which is less than 800 m deep; 2) two deep basins (> 4000 m) located to the west and east STV and; 3) continental shelves, which surround the South Shetland and Elephant Islands. The great topographical variety directly influences the current system (Zhou et al., 2006; Sangrà et al., 2017). In this region, intense interactions occur between the ACC, the Bransfield Current, and the Weddell Sea waters (Zhou et al., 2006). Antarctic Surface Waters occupy the upper layer of the ACC up to 200 m. Below the Antarctic Surface Waters and at intermediate depths, the Deep Circumpolar Water, with salinity between 34.60 and 34.73, occupies most of the water column (Garcia et al., 2002). The bottom water temperature varies between − 1.0 and 0.53 ºC (Gordon and Nowlin, 1978 ). 3. Materials and Methods The samples used in the present research come from two areas with distinct oceanographic and bathymetric characteristics (Figure 1). The first area is located in offshore regions, located between the Bransfield Strait and the DP (depths between 472-490 m) and the second is in the Drake Passage (at depths of 3,700 and 3,850 m). The sediment samples were collected onboard the Polar Vessel Almirante Maximiano (of the Brazilian Navy) during the Antarctic operations (OPERANTAR) XXXI and XXXII, which took place in January 2013 and January 2014, respectively. Five surface sediment samples (EB-1, EB-2, EB-3, EB-4, and EB-5) were collected during OPERANTAR XXXI, and; two surface sediment samples were collected (DK-1 and DK-2) during OPERANTAR XXXII. The geographical coordinates of the sampling stations are presented in Table 1. Sediment collection was carried out using a box-corer sampler of dimensions 60 x 40 x 60 cm. When the sampler was brought on board, the supernatant water was siphoned, and the oxidized surface layer (0-2 cm) was scrapped. The samples to study foraminifera were preserved with a solution of 70% alcohol and Bengal Rose for the identification of living organisms (Walton, 1952). 3.1 Foraminifera studies Once in the laboratory, the samples were homogenized, and 20 cm 3 aliquots were extracted and washed in 250 µm and 63 µm mesh sieves, to eliminate the fine fraction and to facilitate the screening of organisms in the retained fraction in the sieves (Scott et al., 2001; Murray, 2006; Schönfeld et al., 2012). After drying in an oven at a temperature < 50 °C, the densiometric separation of foraminifera was carried out by flotation in zinc chloride (Semensatto, Jr. and Dias-Brito, 2007). As the study is based on living organisms (stained with Bengal Rose), whose abundance is reduced, the most frequent species, i.e., Adercotryma glomeratum (Brady, 1878), was selected for this analysis. This species is the only one that occurs in all studied stations and in sufficient abundance to allow comparisons between various stations. Thus, the specimens of A. glomeratum stained with Bengal Rose were picked and mounted on micropaleontological slides. Forty specimens of living A. glomeratum were collected from each sample. In total, 280 specimens of this species were analyzed morphometrically. The picked stained specimens of A. glomeratum were photographed using a digital camera (AxioCam SV6), coupled to the Zeiss Stemi SV6 stereomicroscope. Then, the major axis of photographed specimens was measured, one by one, using the Zeiss program AxioVision ©. The obtained values were tabulated in spreadsheets. The tests’ size found in each station was classified into four classes: small ( 500 µm). 3.2 Sediment grain size The granulometric analyses of the samples EB-1 to EB-5 followed the sieving and pipetting method described in Suguio (1973), in which the percentages of the granulometric fractions (Shepard, 1954) are calculated through the sediment decanting time. The granulometric analyses of the samples belonging to DK-1 and DK-2 were performed utilizing a Malvern 2000 laser diffractometer, obtaining a continuous curve of granulometric distribution in volume based on laser diffraction in a sample dispersed in water (Hydro dispenser, for muddy samples). In all samples, the sediment was classified according to the granulometric scale established by Shepard (1954). 3.3 Statistical analysis Morphometric data of A. glomeratum and sediment grain size data were transformed by log (x+1). They were submitted to multivariate statistical analyses: Cluster Analysis (CA), and Multiple Linear Regression Analysis. An R-mode and a Q-mode Cluster analysis, based on 1-Pearson r and Complete Linkage, were also used to group the stations and the analyzed variables, aiming to make an interpretation of the morphometric data of A. glomeratum in the analyzed stations as a function of grain size parameters and water depth. Multiple linear regression analysis was applied to compare data acquired in station DK-2 (where the most dissimilar data were found) with the other stations. 4. Results 4.1 Granulometric characteristics of sediment The samples EB-1 to EB-5 have a predominance of sand classes and are mostly composed of very fine sand to medium fractions (Table 2) but also have coarse sand and granules fractions. According to the classification of Shepard (1954), the sediment found in these stations is sandy. The sediments collected in the stations DK-1 and DK-2 are classified, according to Shepard (1954), as silt and have a predominance of fine fraction classes, mainly silt fraction (Table 2). 4.2 Morphometric results The distribution of measures, mean values, and standard deviation for each station are shown in Figure 2. The specimens’ size of A. glomeratum from EB-1 to EB-5 are between 63 and 250 µm and can be classified as small and medium (Table 3). No large and very large tests were found in these stations (Table 3). The specimens’ size of A. glomeratum from DK-1 and DK-2 are between 63 and 500 µm and can be classified as small, medium, and large (Table 3). No very large tests were found in these stations (Table 3). The number of observations for the major axis length (µm) of the measured specimens of A. glomeratum (40 specimens per station) presented in Figure 3 shows that: the highest number of measurements observed in all stations is between 80 and 200 µm; however, a large number of specimens with dimensions between 200 and 310 µm were only found in the stations DK-1 and DK-2; individuals with dimensions >310 µm were not found in the studied sites; the most significant size standard deviations for A. glomeratum were found in DK-1 and DK-2. Data presented in Appendix 1 shows that the mean size of the tests and the respective standard deviation were smaller in the stations EB-1 to EB-5 than in DK-1 and DK-2. Thus, less size variability was observed in the stations EB-1 to EB-5. 4.3 Comparison morphometric data of A. glomeratum with grain size and depth data The Q-mode cluster analysis based on depth, sediment grain size parameters and morphometric data of A. glomeratum (Fig. 4, a) discriminates two groups of stations: DK-1 and DK-2 (I) and the stations EB-1 to EB5 (II). On the other hand, the Mode-R cluster analysis based on the same variable shows that this species' largest sizes and highest mean and standard deviation values tend to occur in fine-grained sediments with higher clay and silt fractions (Fig. 4, b). The DK-2 station, with the highest standard deviation difference from the other stations, was compared through multiple linear regression analysis based on the size of the major axis of 40 specimens of A. glomeratum , sediment grain size parameters, and depth to the other stations (Table 4). The results of this analysis indicate that the DK-2 station is similar to the DK-1 in terms of analyzed data and shows greater differences with the other stations. 5. Discussion The two groups of stations discriminated by cluster analysis (Fig. 4 , a) have different sediment grain size characteristics. While the subtract of the stations EB-1 to EB-5 comprises sandy sediment, stations DK-1 and DK-2 have silty sediments, with fine fraction contents between ≈ 92–94%. The difference in sediment grain size found in the two regions allows us to suppose that there are different bottom hydrodynamic regimes. Bottom currents in the stations EB-1 to EB-5 area should be more energetic than in the DK-1 and DK-2 regions. However, it can also be hypothesized that the first region (with stations EB-1 to EB-5) may receive materials from the iceberg's melting, explaining the presence of coarse particle size fractions (medium sand to very coarse sand and granules) in the sediment composition. Such a record is not evident at stations DK-1 and DK-2. It should also be noted that DK-1 and DK-2 are much deeper (3700 m and 3850 m) than stations EB-1 to EB-5 (472–492 m). The specimens analyzed live under the influence of the Deep Circumpolar Water, with low salinities and temperatures (between 34.60-34.73 and − 1.0 ºC and 0.53 ºC, respectively; Gordon and Nowlin, 1978 ; Garcia et al., 2002). In fact, A. glomeratum (an agglutinated foraminifera species) is frequently found in cold and/or deep-sea regions (Gooday, 1988 ; Gooday and Turley, 1990 ; Harloff and Mackensen, 1997; Kurbjeweit et al., 2000; Fontanier et al., 2002; Ernst and Zwaan, 2004; Bella et al., 2016) where the abundance of carbonate foraminifera is rare, due to the difficulty of forming and maintaining their shells due to the presence of corrosive waters. corrosive waters. In stations EB-1 to EB-5, the general average size of the longer axis of this species is ~ 130 µm, while in stations DK-1 and DK-2, that average is ~ 165 µm. The results show that despite the highest number of observed measurements in the analyzed stations being between 90 and 180 µm (Figs. 2 , 3 ), the biggest dimensions of A. glomeratum tests (between 200 and 320 µm) were recorded only in the deepest stations (DK-1 and DK-2), where the highest standard deviation values were found too. The statistical results (Fig. 5) show that station DK-2 is significantly different from the others but similar to station DK-1. The cluster analysis results (Fig. 4 B) also suggest that the highest mean and maximum values of A. glomeratum sizes are associated with finer-grained sediments found in the deeper stations. Adercotrima glomeratum is the most abundant species in the study area, mainly in the composition of the living assemblages from the upper 2 cm of surface sediments, where it is frequently the dominant species (Passos, 2019 ). This agrees with the fact that it is an opportunistic species with a great capacity to colonize environments and with wide tolerance to environmental variability, having a cosmopolitan character and generalist behavior (Fontanier et al., 2002; Ernst and Zwaan, 2004; Bella et al., 2016). Many studies show that the difference in the size of tests of foraminifera species is related to depth (Theyer, 1969; Corliss, 1979; Loubere et al., 1988; Majewski and Pawlowski, 2010; Gooday et al., 2017). For instance, Globocassidulina sp. presented tests with reduced size in deeper regions of the Pacific Ocean, Southeast Indian Ocean, and North Atlantic (Theyer, 1969; Corliss, 1979; Loubere et al., 1988). Majewski and Pawlowski (2010) observed that, in the Antarctic Peninsula, some Globocassidulina spp. showed reduced sizes in deeper regions. These studies have shown a tendency for many species of foraminifera (the vast majority with carbonated-tests species) to decrease in size as depth increases. The tests of A. glomeratum analyzed in this study, on the other hand, present an opposite pattern than that reported by the mentioned studies since they tend to show the biggest tests in deeper regions. When we analyze only the studies that have used foraminifera species with agglutinating tests, we can identify that this relationship is inversely proportional to that of calcareous test species. Even though research investigating differences in the size of tests from agglutinating species is rarer, it does show that individuals tend to increase in size according to depth. For example, Theyer (1969) found that Cyclammina cancellata had bigger individuals with more robust walls at a depth of 2000 m, while the individuals of this species found at 500 m were smaller and more fragile. Theyer (1969) deduced that the temperature can be the main factor that controls this pattern. The group of Xenophyophores (agglutinating, monothalamids, giant, and sensitive foraminifera) are found only in deep regions and indicate the ability to adapt to the abyssal areas by increasing the tests (Gooday et al., 2017). These examples suggest that the agglutinating species present systems of adaptation to the deep regions different from that of calcareous tests. Most studies reported that A. glomeratum prefers muddy sediments in bottoms that receive phytodetritus from the sea surface (Gooday, 1988 ; Gooday and Turley, 1990 ; Rodrigues et al., 2015). Based on these remarks, we can say that the deepest regions of DP provide a more stable environment for this species' development since muddy substrates are generally related to calm hydrodynamic conditions. This calm and stable environment may allow the individuals to complete their life cycle and reach larger sizes. In addition, the deepest stations show the greatest variation in size, indicating the presence of organisms at different stages of development. On the contrary, this work also suggests that, in environments disturbed by strong hydrodynamic conditions or by the deposition of sediments resulting, for example, from iceberg melting, this species has short life cycles and forms populations of smaller individuals. When the environmental conditions are stable, the life cycles of this species may be longer, and the populations may include larger organisms. Thus, the results of this study show that the size of A. glomeratum in the deep ocean can be an indicator of environmental disturbance or stability. 6. Conclusion Adercotrymma glomeratum is one of the main species in the living assemblages of foraminifera in the deep-sea of Antarctica, where the waters are cold, have salinity below the normal oceanic one and corrosive waters that prevent or hinder calcification of carbonate species. The results of this work show that in these conditions, in areas of the deep ocean subject to environmental disturbance caused by strong currents or by the discharge of sediment from the iceberg melting, for example, the individuals in A. glomeratum populations are smaller. While in stable areas, this species forms populations of bigger individuals. Thus, the data obtained in this work suggest that the size of A. glomeratum can be used as a tracer of environmental disturbance or stability in deep-sea areas, such as Antarctica. Declarations Author Contribution Each author contributed significantly to this study as follows: C.C.P. and W.D. conceived the study and designed the methodology. W.D. conducted the field sampling. C.C.P. performed the laboratory analyses. C.C.P. and M.V.A.M. interpreted the data, wrote the main manuscript text, and prepared the figures and tables. All authors reviewed and approved the final version of the manuscript.This statement replaces any other written within the manuscript and is the one that will be published. Acknowledgement The present work is part of broader research coordinated by Professor Antônio Carlos Rocha-Campos (in memoriam) from the Institute of Geosciences of the University of São Paulo (IGcUSP) and Professor Wânia Duleba, from the School of Arts, Sciences and Humanities of University of São Paulo (EACH-USP), about methane emanations related to hydrothermalism (vents and fumaroles) and gas hydrates (cold seeps) located in the Bransfield Strait, Drake and Larsen Platform region (PROANTAR-CNPq Proc. 55036 / 2009-7). The authors would like to thank the Brazilian Antarctic Program (PROANTAR), the Captain and crew of the Navio Polar Maximiano (Marinha do Brasil) for logistical support, and the Coordination of Improvement of Higher Education Personnel (CAPES) for the doctoral fellowship (Camila Cunha Passos). Special thanks to V. D. Solovyov (Institute of Geophysics of National Academy of Science of Ukraine) for the geographical coordinates of the locals rich in hydrate gas and Anderson T. S. Ferreira for the map. References ALVE E. (1995). Benthic foraminiferal responses to estuarine pollution: a review. Journal Foraminiferal Research , 25 (3), 190–203. MURRAY, J. W. (2001). Temporal variability in vertical distributions of live (stained) intertidal foraminifera. southern England. Journal of Foraminiferal Research 31(1): 12–24. 2001. AMAO, A. O., QURBAN M.A., KAMINSKI M.A., JOYDAS T.V., MANIKANDAN P.K. and FRONTALINI F (2020). Dataset showing the abundance and distribution of benthic foraminifera in relation to marine sediment parameters from western Arabian Gulf. Data in Brief , 28 , 105014. BELLA L., INGRASSIA M., FREZZA V., CHIOCCI F.L. and MARTORELLI E. (2016). The response of benthic meiofauna to hydrothermal emissions in the Pontine Archipelago. Tyrrhenian Sea (central Mediterranean Basin). Journal of Marine Systems 164: 53–66. BERNHARD J.M., BARRY J.P., BUCK K. and STARCZAK V.R. (2009). Impact of intentionally injected carbon dioxide hydrate on deep-sea benthic foraminiferal survival. Global Change Biology 15: 2078–2088. MEDIOLI, F. S. (1991). Morphological Variation of Benthic Foraminiferal tests in response to Changes in Ecological Parameters: a review. Journal Paleontology , 65 (2), 175–185. SAURIAU P.G, B. O. U. C. H. E. T. V. M. P., DEBENAY, J. P., & MERMILLOD-BLONDIN F., S. C. H. M. I. D. T. S., AMIARD J.C. and DUPAS. B (2009). Influence of the mode of macrofauna-mediated bioturbation on the vertical distribution of living benthic foraminifera: First insight from axial tomodensitometry. Journal of Experimental Marine Biology and Ecology , 371 , 20–33. BUZAS, M. A. (1974). Vertical distribution of Ammobaculites in the Rhode River. Maryland. Journal of Foraminiferal Research , 4 (3), 144–147. BUZAS, M. A. (1997). Vertical distribution of Foraminifera in the Indian River. Florida. Journal of Foraminiferal Research , 7 (3), 234–237. EL-KAHAWY, C. E. S. B. R. O. N. F. G. E. S. L. I. N. E. J. O. R. I. S. S. E. N. F. J. D. E. L. G. A. R. D. M. L. C. H. A. R. R. I. E. A. U. L. D. E. F. L. A. N. D. R. E. D., EL-SHAFEIY, R. M. and, & HELAL, S. A. (2018). Morphological deformities of benthic foraminifera in response to nearshore pollution of the Red Sea. Egypt. Environmental Monitoring Assessment , 190 , 312. CORLISS B. (1979). Size variation in the deep-sea benthonic foraminifer Globocassidulina subglobosa (Brady) in the Southeast Indian Ocean. Journal Foraminiferal Research 9: 50–60. ERNST S. and ZWAAN B. (2004). Effects of experimentally induced raised levels of organic flux and oxygen depletion on a continental slope benthic foraminiferal community. Deep-Sea Research I 51: 1709–1739. LE, E. R. N. S. T. S. R. M. O. R. V. A. N. J. G. E. S. L. I. N. E., BIHAN, A., & JORISSEN, F. J. (2006). Benthic foraminiferal response to experimentally induced Erika oil pollution. Marine Micropaleontology , 60 , 76–93. FINGER, K. L., & LIPPS, J. H. (1981). Foraminiferal decimation and repopulation in an active volcanic caldera. Deception Island Antarctica Micropaleontology , 27 (2), 111–139. FONTANIER C., JORISSEN F.J., LICARI L., ALEXANDRE A., ANSCHUTZ P. and CARBONEL P. (2002). Live benthic foraminiferal faunas from the Bay of Biscay: faunal density. composition. and microhabitats. Deep-Sea Research I 49: 751–785. FRONTALINI F. and COCCIONI R. (2008). Benthic foraminifera for heavy metal pollution monitoring: A case study from the central Adriatic Sea coast of Italy. Estuarine Coastal and Shelf Science 76: 404–417. GARCÍA, M. A., RÍOS A.F., C. A. S. T. R. O. C. G., & DOVAL, M. D., ROSÓN G., GOMIS D. and LÓPEZ O (2002). Water masses ans distribution of physico-chemical properties in the Western Bransfield Strait and Gerlache Strait during Austral Summer 1995/96. Deep-Sea Research II , 49 (4–5), 585–602. GOODAY A. J., HOLZMANN M., CAULLE C., GOINEAU A., KAMENSKAYA O., WEBER A. A. T. and PAWLOWSKI J. (2017). Giant protists (xenophyophores, Foraminifera) are exceptionally diverse in parts of the abyssal eastern Pacific licensed for polymetallic nodule exploration. Biological Conservation 207:106–116. GOODAY, A. J. (1988). A response by benthic foraminifera to phytodetritus deposition in the deep sea. Nature , 332 , 70–73. GOODAY, A. J., & TURLEY, C. M. (1990). Responses by benthic organisms to inputs of organic material to the ocean floor: a review. Philosophical Transactions of The Royal Society , 331 , 119–138. NOWLIN, W. D. (1978). The basin waters of Bransfield Strait. Journal of Physical Oceanography , 8 , 258–267. HARLOFF J. and MACKENSEN A. (1997). Recent benthic foraminiferal associations and ecology of the Scotia Sea and Argentine Basin. Marine Micropaleontology 31: 1–29. ISHMAN, S. E., & DOMACK, E. W. (2004). Oceanographic controls on benthic foraminifers from the Bellingshausen margin of the Antarctic Peninsula. Marine Micropaleontology , 24 , 119–155. JÉZÉQUEL, V. M. (2016). Locomotion speed of the benthic foraminifer Ammonia tepida exposed to different nitrogen and carbono sources. Journal of Sea Research , 118 , 52–58. JONES, R. W. (2013). Foraminifera ans their Application (p. 263). Cambridge. University. JOUGHIN I. and ALLEY R.B. (2011). Stability of the Weste Antarctic ice she in a warming world. Nature Geocience 4: 506–513. KURBJEWEIT F., SCHMIEDL G., SCHIEBEL R., HEMLEBEN CH., PFANNKUCHE O., WALLMANN K. and SCHÄFER P. (2000). Distribution. biomass and diversity of benthic foraminifera in relation to sediment geochemistry in the Arabian Sea. Deep-Sea Research II 47: 2913–2955. LE, C. A. D. R. E. V., & DEBENAY, J. P. (2006). Morphological and cytological response of Ammonia (foraminifera) to copper contamination: implication for the use of foraminíferas bioindicators of pollution. Environmental Pollution , 142 , 304–317. LOUBERE P., BANONIS G. and JAKIEL R. (1988). Globocassidulina Subglobosa (Brady): Environmental control of species abundance and specimen test size. Journal Foraminiferal Research 18 (1): 6–15. FIITTERER, D. K. (1990). Benthic Foraminiferal assemblages from the eastern Weddell Sea between 68 and 73°S: Distribution. ecology and fossilization potential. Marine Micropaleontology , 16 , 241–283. MAJEWSKI W. and PAWLOWSKI J. (2010). Morphologic and molecular diversity of the foraminiferal genus Globocassidulina in Admiralty Bay, King George Island. Antarctic Science 22(3):271–281. MARTINS, M. V. A., LAUT L.L.M., F. R. O. N. T. A. L. I. N. I. F., FONSECA M.C.M., S. E. Q. U. E. I. R. A. C. R. O. D. R. I. G. U. E. S. R., DELAVY, B. E. R. G. A. M. A. S. C. H. I. S. P. E. R. E. I. R. A. E., & FIGUEIREDOJR, F. P. (2016). Controlling factors on the abundance. diversity and size of living benthic foraminifera in the NE sector of Guanabara Bay (Brazil). Journal of Sedimentary Environments , 1 (4), 393–410. MILKOV, A. V. (2000). Worldwide distribution of submarine mud volcanoes and associated gas hydrates. Marine Geology , 167 (1–2), 29–42. MURRAY, J. W. (1991). Ecology and paleoecology of benthic foraminífera (397pp.). Logman Scientific and Technical. MURRAY, J. W. (2006). Ecology and applications of benthic foraminífera (p. 426). Cambridge University Press. PASSOS, C. C. (2019). Ecologia de foraminíferos bentônicos das regiões da Passagem do Drake e Ilha de Marambio. Península Antártica. PhD Thesis (Postgraduate Program in Sustainability). School of Arts. Sciences and Humanities at the University of São Paulo. Sao Paulo. 261pp. ROBERTSON R., VISBECK M., GORDON A.L. and AHRBACH E. (2002). Long-term temperature trends in the deep waters of the Weddell Sea. Deep-Sea Research II 49: 4791–4806. JOUGHIN. I.; ALLEY. R. B. 2011. Stability of the West Antarctic ice sheet in a warming world. Nature Geocience 4:506–513. EICHLER, R. O. D. R. I. G. U. E. S. A. R. P.P.B. and EICHLER B.B (2013). Foraminifera in two inlets fed by a tidewater glacier. King George Island Antarctic Peninsula Journal Foraminiferal Research , 43 (3), 209–220. HERNÁNDEZ-ARENCIBIAC M., S. A. N. G. R. À. P. S. T. E. G. N. E. R. B. A., & MARRERO-DÍAZC A., S. A. L. I. N. A. S. A. C. AGUIAR-GONZÁLEZD B., HENRÍQUEZ-PASTENEE C. and MOURIÑO-CARBALLIDO B. 2017. The Bransfield Gravity current. Deep-Sea Research I 119: 1–15. SANTINI, M. F. (2011). Estrutura termohalina e massas d'água na vizinhança da Península Antártica a partir de dados in situ coletados por elefantes-marinhos do sul (Mirounga leonina). Master's Dissertation (Post-Graduate Program in Physical Oceanography). Oceanographic Institute. University of Sao Paulo. São Paulo. 93pp. SCHÖNFELD J., ALVE E., GESLIN E., JORISSEN F., KORSUN S. and SPEZZAFERRI S. (2012). The FOBIMO (FOraminiferal BIo-MOnitoring) initiative - Towards a standardized protocol for soft-bottom benthic foraminiferal monitoring studies. Marine Micropaleontology 94(95): 1–13. MEDIOLI, S. C. O. T. T. D. B. F.S. and, & SCHAFER, C. T. (2001). Monitoring in coastal environments using foraminifera and thecamoebian indicators (p. 192). Cambridge University Press. SEMENSATTOJR, D. L., & DIAS-BRITO D (2007). Alternative saline solutions to float foraminiferal tests. Journal of Foraminiferal Research , 37 (3), 265–269. SHEPARD, F. P. (1954). Nomenclature based on sand-sily-clay ration. Journal od Sedimentary Petrology , 24 (3), 151–158. KORCHAGIN I.N., S. O. L. O. V. Y. O. V. V. D. B. A. K. H. M. U. T. O. V. V. G., LEVASHOV S.P., YAKYMCHUK N.A. and, & BOZHEZHA, D. N. (2011). Gas Hydrates Accumulations on the South Shetland Continental Margin: New Detection Possibilities. Journal of Geological Research , 2011 , 1–8. STEFANOUDIS P.V., SCHIEBEL R., MALLET R., DURDEN J.M., BETT B.J., and GOODAY A.J. (2016). Agglutination of benthic foraminifera in relation to mesoscalebathymetric features in the abyssal NE Atlantic (Porcupine Abyssal Plain). Marine Micropaleontology 123: 12–28. SUGUIO K. Introdução à sedimentologia. (1973). São Paulo, Edgard Blücher. 165pp. THEYER F. (1969). Size-Depth Variation in Foraminifer Cyclammina Cancellata Brady from Peru-Chile Trench Area. Advancing the Word of Petroleum Geoscience Bulletin 53 (2): 466–467. THORPE, S. E., HEYWOOD K.J., BRANDON M.A. and, & STEVENS, D. P. (2002). Variability of the southern Antarctic Circumpolar Current Front north of South Georgia. Journal of Marine Systems , 451 , 87–105. WALTON, W. R. (1952). Techniques for recognition of living foraminífera. Cushman Foundation Research , 3 (2), 56–64. WOLLENBURG, J. E. and KUHNT W (2000). The response of benthic Foraminifers to carbon flux and primary production in the Arctic Ocean. Marine Micropaleontology , 40 , 189–231. YANKO V., AHMAD. M. and KAMINSKI. M. (1998). Morphological deformities of benthic foraminiferal tests in response to pollution by heavy metals: implications for pollution monitoring. Journal Foraminiferal Research 28(3): 177–200. DORLAND, R. D. (2006). The western boundary current in the Bransfield Strait. Antarctica. Deep-Sea Research I , 53 , 1244–1252. Tables Table 1 - Collection Dates, water depth (in meters) and geographic coordinates of the sampling station in the Drake Passage during OPERANTAR XXXI and XXXII. OPERANTAR Cores Sampling date Water depth (m) Latitude Longitude XXXI EB-1 24/01/2013 490 61.430017 S 56.950700 W XXXI EB-2 24/01/2013 492 61.425683 S 56.954767 W XXXI EB-3 24/01/2013 483 61.419317 S 56.961167 W XXXI EB-4 24/01/2013 472 61.419617 S 56.949367 W XXXI EB-5 24/01/2013 486 61.421050 S 56.932167 W XXXII DK-1 17/01/2014 3700 61.074567 S 57.883917 W XXXII DK-2 17/01/2014 3850 61.072671 S 57.880893 W Table 2 - Percentage of sediment fractions according to Wentworth (1922) and classification of the sediment according to Shepard (1954) in the analyzed stations. Legend: Sand F – sand fractions (63-2000 µm); Fine F – fine fraction (<63 µm); Tsand (%) – total percentage of sand fractions (63-2000 µm); Fines (%) – total percentage of fine fractions (<63 µm); Granules (%) – sediment faction between 2000-4000 µm; VCSF – very coarse sand fraction (1000-2000 µm); CSF - coarse sand fraction (500-1000 µm); MSF - medium sand fraction (250-500 µm); FSF – fine sand fraction (125-250 µm); VFSF – very fine sand fraction (63-125 µm); silt – silt fraction (fine sand fraction (2-63 µm); clay – clay fraction (<2 µm); Stations/SF EB-1 EB-2 EB-3 EB-4 EB-5 DK-1 DK-2 Granules (%) 9.22 3.15 2.68 9.70 4.85 0.00 0.00 Sand F (%) VCSF 10.28 4.72 4.38 8.30 8.16 0.00 0.00 CSF 9.77 18.63 9.80 17.28 10.50 0.00 0.00 MSF 16.18 20.48 22.62 20.27 15.92 0.00 0.07 FSF 25.15 20.38 27.59 22.19 24.95 0.11 1.02 VFSF 12.19 13.67 12.60 6.26 15.93 7.55 4.92 Fine F (%) Silt 10.42 11.75 11.36 8.68 10.31 80.19 83.81 Clay 6.79 7.21 8.95 7.33 9.39 12.15 10.17 Tsand (%) 73.57 77.89 77.00 74.30 75.45 7.66 6.01 Fines (%) 17.21 18.97 20.32 16.01 19.70 92.34 93.99 Classification Sand Sand Sand Sand Sand Silt Silt Table 3 - Size ranges of specimens of A. glomeratum found in the analyzed stations. The number of specimens and the percentage (in brackets) of the total number of analyzed individuals (40) were presented for each size. Stations/ Category EB-1 EB-2 EB-3 EB-4 EB-5 DK-1 DK-2 Total measured specimens 40 40 40 40 40 40 40 Small tests (<125µm) 12 (30%) 20 (50%) 26 (65%) 12 (30%) 25 (62.5%) 3 (7.5%) 10 (25%) Medium tests (125-250µm) 28 (70%) 20 (50%) 14 (35%) 28 (70%) 15 (37.5%) 34 (85%) 27 (67.5%) Large tests (250-500 µm) --- --- --- --- --- 3 (7.5 %) 3 (7.5%) Very large tests (>500µm) --- --- --- --- --- --- --- Table 4. b* Std.Err. b Std.Err. t(6) p -value Intercept -0.10 0.44 -0.22 0.83 EB-1 -0.26 0.39 -0.51 0.77 -0.67 0.52 EB-2 -0.26 0.30 -0.49 0.56 -0.88 0.40 EB-3 0.11 0.30 0.21 0.55 0.38 0.71 EB-4 0.18 0.25 0.35 0.49 0.71 0.50 EB-5 0.24 0.45 0.48 0.90 0.54 0.61 DK-1 0.98 0.06 0.96 0.06 17.04 0.00 Additional Declarations No competing interests reported. Supplementary Files Appendix1.xlsx Cite Share Download PDF Status: Published Journal Publication published 17 Jan, 2025 Read the published version in Journal of Sedimentary Environments → Version 1 posted Editorial decision: Revision requested 11 Jul, 2024 Reviews received at journal 11 Jul, 2024 Reviewers agreed at journal 08 Jul, 2024 Reviews received at journal 28 Jun, 2024 Reviewers agreed at journal 21 Jun, 2024 Reviewers invited by journal 19 Jun, 2024 Editor assigned by journal 19 Jun, 2024 Submission checks completed at journal 14 Jun, 2024 First submitted to journal 13 Jun, 2024 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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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-4578446","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":322853030,"identity":"ef09c510-c7a2-46e9-a195-e408551418eb","order_by":0,"name":"Camila Cunha PASSOS","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9UlEQVRIiWNgGAWjYLCDAw8YbIAUY+MB4rUkMKSBtDQQr4UhgeEwRC8+Rebsxx9/+PDHjoG//XTigYSa83Zr2w8DbamxicalxbInx0xyZlsyg8SZ3A0HEo7dTt52JhGo5VhabgMOLQYHctiYeYFqDBhAWthuJ5sdAGphbDiMW8v5548/8/wBauF/C9Ty71yy2fmHBLTcSDCQ5mEDapEA2pLYdsDO7AYBWyxnvAH7hUfiBtCWxL7kBLMbQFsS8PjFnD8dHGJy/P25mz98+GZnb3Y+/eGDDzU2uB0GpXlgAolglQk4lCNrgQN7PIpHwSgYBaNghAIAmZ1pS3HZx2oAAAAASUVORK5CYII=","orcid":"","institution":"School of Arts, Sciences and Humanities","correspondingAuthor":true,"prefix":"","firstName":"Camila","middleName":"Cunha","lastName":"PASSOS","suffix":""},{"id":322853031,"identity":"34adc565-bf22-43e7-80e1-8e6616f2859a","order_by":1,"name":"Maria Virginia ALVES MARTINS","email":"","orcid":"","institution":"Rio de Janeiro State University","correspondingAuthor":false,"prefix":"","firstName":"Maria","middleName":"Virginia ALVES","lastName":"MARTINS","suffix":""},{"id":322853032,"identity":"61f31a7f-3756-465c-adef-f878355dea8d","order_by":2,"name":"Wânia Duleba","email":"","orcid":"","institution":"School of Arts, Sciences and Humanities","correspondingAuthor":false,"prefix":"","firstName":"Wânia","middleName":"","lastName":"Duleba","suffix":""}],"badges":[],"createdAt":"2024-06-13 22:36:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4578446/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4578446/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s43217-024-00214-5","type":"published","date":"2025-01-17T15:57:04+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":60594877,"identity":"fd90c8b5-f83e-42c1-a8bd-68b48d0e9681","added_by":"auto","created_at":"2024-07-18 15:26:16","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":297397,"visible":true,"origin":"","legend":"\u003cp\u003eStudy area and sampling stations\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4578446/v1/c6e6f690a001a3d4d776bc98.jpg"},{"id":60594868,"identity":"e0054cce-179d-43f4-889e-5868f09f18b1","added_by":"auto","created_at":"2024-07-18 15:26:15","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":66035,"visible":true,"origin":"","legend":"\u003cp\u003eBoxplot with the distribution of the major axis length (µm) of \u003cem\u003eA. glomeratum\u003c/em\u003e tests based on 40 tests measured in each station.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4578446/v1/70d31ea46528d8ed20775750.png"},{"id":60594873,"identity":"9e224129-58aa-43d8-9997-afa98881c0ba","added_by":"auto","created_at":"2024-07-18 15:26:15","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":52764,"visible":true,"origin":"","legend":"\u003cp\u003eNumber of observations for the major axis length (µm) of the measured specimens of \u003cem\u003eA. glomeratum\u003c/em\u003e.\u003c/p\u003e","description":"","filename":"Figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4578446/v1/9818e7e8ed5d4ee0531f459a.jpg"},{"id":60594872,"identity":"edd27a2d-2ad6-4f39-b0c6-840525071b4b","added_by":"auto","created_at":"2024-07-18 15:26:15","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1667178,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eA\u003c/em\u003e. Q-mode and B.\u003cem\u003e \u003c/em\u003eR-mode cluster analysis based on depth, sediment grain size parameters and morphometric data of\u003cem\u003e A. glomeratum\u003c/em\u003e.\u003cem\u003e \u003c/em\u003eLegend: Tsand – total percentage of sand fractions (63-2000 µm); Fines – total percentage of fine fractions (\u0026lt;63 µm; Gran – granules, sediment faction between 2000-4000 µm; VCSF – very coarse sand fraction (1000-2000 µm); CSF - coarse sand fraction (500-1000 µm); MSF - medium sand fraction (250-500 µm); FSF – fine sand fraction (125-250 µm); VFSF – very fine sand fraction (63-125 µm); Silt – silt fraction (fine sand fraction (2-63 µm); Clay – clay fraction (\u0026lt;2 µm). Related to the major axis length measurements of 40 specimens of \u003cem\u003eA. glomeratum\u003c/em\u003e (A.g) found in the analyzed stations: Min.A.g – minimum values; Mean.A.g –mean values; Max.A.g – maximum values; SD.A.g –standard deviation.\u003c/p\u003e","description":"","filename":"Figure4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4578446/v1/7e182a0a42fd8747dd255659.jpg"},{"id":74284490,"identity":"30872189-7653-40f9-aed1-2c94b38f048e","added_by":"auto","created_at":"2025-01-20 16:07:51","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2961370,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4578446/v1/a3116255-258a-4e38-96ac-a95481253af8.pdf"},{"id":60594964,"identity":"f563b6e9-4c1d-4829-8607-62113ccb081c","added_by":"auto","created_at":"2024-07-18 15:26:17","extension":"xlsx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":12738,"visible":true,"origin":"","legend":"","description":"","filename":"Appendix1.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-4578446/v1/85f39a7e4dbbbd8ab1d17cfe.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Developing a palaeoceanographic proxy based on the dimensions of Adercotryma glomeratum populations: a case study in Drake Passage region (Antarctic Peninsula)","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThere is still much to discover about the impacts that highly dynamic environments have on benthic marine organisms (Bernhard et al., 2009) in offshore environments, directly influenced by the characteristics of the bottom water bodies and the nutrient supply of the sea surface. The Southern Ocean is a unique environment, as it is the origin of several water bodies that move around the planet by thermohaline circulation (Robertson et al. 2011). With the Drake Passage (DP) opening, the Antarctic Peninsula (AP) can be considered the main obstacle encountered by the Antarctic Circumpolar Current (ACC), with great importance in the region, as it is the only current that links the Atlantic, Indian, and Pacific Oceans (Joughin and Alley, 2011).\u003c/p\u003e \u003cp\u003eDespite its particular conditions, the factors that condition the characteristics of the living communities of the Southern Ocean are still poorly understood, particularly those that condition benthic meiofaunal organisms, such as foraminifera. Benthic foraminifera can respond quickly in different ways to environmental variations (Wollenburg and Kuhnt, 2000; Boltovskoy et al. 1991; Jones \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2013\u003c/span\u003e, Amao et al. 2020). The use of these organisms to assess impacted areas as indicators of pollution, for example, is frequent, as they can answer to variations in physicochemical characteristics of the environment in which they live (Scott et al. 2001; Bouchet et al., 2009; Cesbron et al., 2016). Their answers include changes in abundance, assemblage composition (Jauffrais et al., 2016; Amao et al., 2020), and morphological modifications (Boltovskoy et al., 1991; Yanko et al., 1998; Stefanoudis et al., 2016; El-Kahawy et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2018\u003c/span\u003e), such as changes in coiling direction, size of the aperture and size, thickness and color of the chamber/s and the test size (Ishman and Domack, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2004\u003c/span\u003e; Murray, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2006\u003c/span\u003e), as well as changes in the chemical composition of the test wall, depending on the water composition. For this reason, they are also used to trace palaeoceanographic and paleoclimatic evolution.\u003c/p\u003e \u003cp\u003eHowever, little is known about the morphological changes of benthic foraminifera in the deep-sea. In extreme environments like Antarctica, the benthic community is subjected to natural environmental stress that often limits the survival of many organisms, such as low temperatures, the presence of corrosive waters, limited food, and dissolved oxygen in the sediment. Because it is a highly dynamic region with unique geological characteristics, AP has a wide range of environments (Finger and Lipps, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e1981\u003c/span\u003e; Mackensen et al., 1990; Milkov, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2000\u003c/span\u003e; Rodrigues et al., 2013). The DP is a region of difficult navigability, with adverse climatic conditions and intense surface currents; therefore, works with the recovery of marine sediments are pretty scarce (Santini, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2011\u003c/span\u003e), especially of benthic foraminifera.\u003c/p\u003e \u003cp\u003eTherefore, this study intends to investigate the influence of the bottom hydrodynamic regime and depth on the dimensions of benthic foraminifera populations in deep-sea settings off the Antarctic Peninsula. To achieve this objective, seven stations located between the Bransfield Strait and the DP were selected (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). This work is essential given the limited knowledge about benthic foraminifera in the DP region and the small number of studies that address morphometric studies of benthic foraminifera in deep-sea environments.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eSome studies have used granulometric ranges from which the organisms are picked, identified, and counted, and their dimensions are assumed to fall within those ranges (Ernst et al., 2006; Frontalini and Coccioni, 2008; Martins et al., \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Most of these works are related to species with carbonated tests and in monitoring studies of coastal regions under high anthropic influence (Alve et al., 1995; Le Cadre and Debenay, 2006). This work also aims to develop a proxy indicator of stability/instability of the conditions prevailing in the deep-sea based on the size of foraminifera, which can be applied in paleoenvironmental reconstructions.\u003c/p\u003e"},{"header":"2. Study area","content":"\u003cp\u003eThe DP is located in the Scotia Sea basin, between South America and the Antarctic Peninsula (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). On average, the central and western portions are deeper, with about 3000 m, and less hilly or flat (Thorpe, \u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e2002\u003c/span\u003e). The region is affected by different and overlapping tectonic regimes, where one plate is subjected to subduction and the other is associated with a tectonic fault (Solovyov et al., 2011).\u003c/p\u003e \u003cp\u003eThe southern portion of the DP has diversified morphology, which includes: 1) the Shackleton Transversal Chain (STC), which is less than 800 m deep; 2) two deep basins (\u0026gt;\u0026thinsp;4000 m) located to the west and east STV and; 3) continental shelves, which surround the South Shetland and Elephant Islands. The great topographical variety directly influences the current system (Zhou et al., 2006; Sangr\u0026agrave; et al., 2017).\u003c/p\u003e \u003cp\u003eIn this region, intense interactions occur between the ACC, the Bransfield Current, and the Weddell Sea waters (Zhou et al., 2006). Antarctic Surface Waters occupy the upper layer of the ACC up to 200 m. Below the Antarctic Surface Waters and at intermediate depths, the Deep Circumpolar Water, with salinity between 34.60 and 34.73, occupies most of the water column (Garcia et al., 2002). The bottom water temperature varies between \u0026minus;\u0026thinsp;1.0 and 0.53 \u0026ordm;C (Gordon and Nowlin, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e1978\u003c/span\u003e).\u003c/p\u003e"},{"header":"3. Materials and Methods","content":"\u003cp\u003eThe samples used in the present research come from two areas with distinct oceanographic and bathymetric characteristics (Figure 1). The first area is located in offshore regions, located between the Bransfield Strait and the DP (depths between 472-490 m) and the second is in the Drake Passage (at depths of 3,700 and 3,850 m). The sediment samples were collected onboard the Polar Vessel Almirante Maximiano (of the Brazilian Navy) during the Antarctic operations (OPERANTAR) XXXI and XXXII, which took place in January 2013 and January 2014, respectively. Five surface sediment samples (EB-1, EB-2, EB-3, EB-4, and EB-5) were collected during OPERANTAR XXXI, and; two surface sediment samples were collected (DK-1 and DK-2) during OPERANTAR XXXII. The geographical coordinates of the sampling stations are presented in Table 1.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSediment collection was carried out using a box-corer sampler of dimensions 60 x 40 x 60 cm. When the sampler was brought on board, the supernatant water was siphoned, and the oxidized surface layer (0-2 cm) was scrapped. The samples to study foraminifera were preserved with a solution of 70% alcohol and Bengal Rose for the identification of living organisms (Walton, 1952).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.1 Foraminifera studies\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOnce in the laboratory, the samples were homogenized, and 20 cm\u003csup\u003e3\u003c/sup\u003e aliquots were extracted and washed in 250 \u0026micro;m and 63 \u0026micro;m mesh sieves, to eliminate the fine fraction and to facilitate the screening of organisms in the retained fraction in the sieves (Scott et al., 2001; Murray, 2006; Sch\u0026ouml;nfeld et al., 2012). After drying in an oven at a temperature \u0026lt; 50 \u0026deg;C, the densiometric separation of foraminifera was carried out by flotation in zinc chloride (Semensatto, Jr. and Dias-Brito, 2007).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAs the study is based on living organisms (stained with Bengal Rose), whose abundance is reduced, the most frequent species, i.e., \u003cem\u003eAdercotryma glomeratum\u003c/em\u003e (Brady, 1878), was selected for this analysis. This species is the only one that occurs in all studied stations and in sufficient abundance to allow comparisons between various stations. Thus, the specimens of \u003cem\u003eA. glomeratum\u003c/em\u003e stained with Bengal Rose were picked and mounted on micropaleontological slides.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eForty specimens of living \u003cem\u003eA. glomeratum\u003c/em\u003e were collected from each sample. In total, 280 specimens of this species were analyzed morphometrically. The picked stained specimens of \u003cem\u003eA. glomeratum\u003c/em\u003e were photographed using a digital camera (AxioCam SV6), coupled to the Zeiss Stemi SV6 stereomicroscope. Then, the major axis of photographed specimens was measured, one by one, using the Zeiss program AxioVision \u0026copy;. The obtained values were tabulated in spreadsheets. The tests\u0026rsquo; size found in each station was classified into four classes: small (\u0026lt;125 \u0026micro;m), medium (125 - 250 \u0026micro;m), large (250 - 500 \u0026micro;m), and very large (\u0026gt; 500 \u0026micro;m).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2 Sediment grain size\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe granulometric analyses of the samples EB-1 to EB-5 followed the sieving and pipetting method described in Suguio (1973), in which the percentages of the granulometric fractions (Shepard, 1954) are calculated through the sediment decanting time. The granulometric analyses of the samples belonging to DK-1 and DK-2 were performed utilizing a Malvern 2000 laser diffractometer, obtaining a continuous curve of granulometric distribution in volume based on laser diffraction in a sample dispersed in water (Hydro dispenser, for muddy samples). In all samples, the sediment was classified according to the granulometric scale established by Shepard (1954).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3 Statistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMorphometric data of \u003cem\u003eA. glomeratum\u003c/em\u003e and sediment grain size data were transformed by log (x+1). They were submitted to multivariate statistical analyses: Cluster Analysis (CA), and Multiple Linear Regression Analysis. An R-mode and a Q-mode Cluster analysis, based on 1-Pearson r\u0026nbsp;and Complete Linkage, were also used to group the stations and the analyzed variables, aiming to make an interpretation of the morphometric data of \u003cem\u003eA. glomeratum\u003c/em\u003e in the analyzed stations as a function of grain size parameters and water depth. Multiple linear regression analysis was applied to compare data acquired in station DK-2 (where the most dissimilar data were found) with the other stations.\u0026nbsp;\u003c/p\u003e"},{"header":"4. Results","content":"\u003cp\u003e\u003cstrong\u003e4.1 Granulometric characteristics of sediment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe samples EB-1 to EB-5 have a predominance of sand classes and are mostly composed of very fine sand to medium fractions (Table 2) but also have coarse sand and granules fractions. According to the classification of Shepard (1954), the sediment found in these stations is sandy. The sediments collected in the stations DK-1 and DK-2 are classified, according to Shepard (1954), as silt and have a predominance of fine fraction classes, mainly silt fraction (Table 2).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.2 Morphometric results\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe distribution of measures, mean values, and standard deviation for each station are shown in Figure 2. The specimens\u0026rsquo; size of \u003cem\u003eA. glomeratum\u003c/em\u003e from EB-1 to EB-5 are between 63 and 250 \u0026micro;m and can be classified as small and medium (Table 3). No large and very large tests were found in these stations (Table 3).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe specimens\u0026rsquo; size of \u003cem\u003eA. glomeratum\u003c/em\u003e from DK-1 and DK-2 are between 63 and 500 \u0026micro;m and can be classified as small, medium, and large (Table 3). No very large tests were found in these stations (Table 3).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe number of observations\u0026nbsp;for\u0026nbsp;the major\u0026nbsp;axis length (\u0026micro;m)\u0026nbsp;of the measured specimens of \u003cem\u003eA. glomeratum\u0026nbsp;\u003c/em\u003e(40 specimens per station)\u0026nbsp;presented in Figure 3 shows that: the highest number of measurements observed in all stations is between 80 and 200 \u0026micro;m; however, a large number of specimens with dimensions between 200 and 310 \u0026micro;m were only found in the stations DK-1 and DK-2; individuals with dimensions \u0026gt;310 \u0026micro;m were not found in the studied sites; the most significant size standard deviations for \u003cem\u003eA. glomeratum\u003c/em\u003e were found in DK-1 and DK-2.\u003c/p\u003e\n\u003cp\u003eData presented in Appendix 1 shows that the mean size of the tests and the respective standard deviation were smaller in the stations EB-1 to EB-5 than in DK-1 and DK-2. Thus, less size variability was observed in the stations EB-1 to EB-5.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.3 Comparison morphometric data of \u003cem\u003eA. glomeratum\u003c/em\u003e with grain size and depth data\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe\u0026nbsp;Q-mode cluster analysis based on depth, sediment grain size parameters and morphometric data of\u003cem\u003e\u0026nbsp;A. glomeratum\u003c/em\u003e (Fig. 4, a) discriminates two groups of stations: DK-1 and DK-2 (I) and the stations\u0026nbsp;EB-1 to EB5 (II). On the other hand, the Mode-R cluster analysis based on the same variable shows that this species\u0026apos; largest sizes and highest mean and standard deviation values tend to occur in fine-grained sediments with higher clay and silt fractions (Fig. 4, b).\u003c/p\u003e\n\u003cp\u003eThe DK-2 station, with the highest standard deviation difference from the other stations, was compared through multiple linear regression analysis based on the size of the major axis of 40 specimens of \u003cem\u003eA. glomeratum\u003c/em\u003e, sediment grain size parameters, and depth to the other stations (Table 4). The results of this analysis indicate that the DK-2 station is similar to the DK-1 in terms of analyzed data and shows greater differences with the other stations.\u003c/p\u003e"},{"header":"5. Discussion","content":"\u003cp\u003eThe two groups of stations discriminated by cluster analysis (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, a) have different sediment grain size characteristics. While the subtract of the stations EB-1 to EB-5 comprises sandy sediment, stations DK-1 and DK-2 have silty sediments, with fine fraction contents between \u0026asymp;\u0026thinsp;92\u0026ndash;94%. The difference in sediment grain size found in the two regions allows us to suppose that there are different bottom hydrodynamic regimes. Bottom currents in the stations EB-1 to EB-5 area should be more energetic than in the DK-1 and DK-2 regions. However, it can also be hypothesized that the first region (with stations EB-1 to EB-5) may receive materials from the iceberg's melting, explaining the presence of coarse particle size fractions (medium sand to very coarse sand and granules) in the sediment composition. Such a record is not evident at stations DK-1 and DK-2. It should also be noted that DK-1 and DK-2 are much deeper (3700 m and 3850 m) than stations EB-1 to EB-5 (472\u0026ndash;492 m).\u003c/p\u003e \u003cp\u003eThe specimens analyzed live under the influence of the Deep Circumpolar Water, with low salinities and temperatures (between 34.60-34.73 and \u0026minus;\u0026thinsp;1.0 \u0026ordm;C and 0.53 \u0026ordm;C, respectively; Gordon and Nowlin, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e1978\u003c/span\u003e; Garcia et al., 2002). In fact, \u003cem\u003eA. glomeratum\u003c/em\u003e (an agglutinated foraminifera species) is frequently found in cold and/or deep-sea regions (Gooday, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e1988\u003c/span\u003e; Gooday and Turley, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e1990\u003c/span\u003e; Harloff and Mackensen, 1997; Kurbjeweit et al., 2000; Fontanier et al., 2002; Ernst and Zwaan, 2004; Bella et al., 2016) where the abundance of carbonate foraminifera is rare, due to the difficulty of forming and maintaining their shells due to the presence of corrosive waters. corrosive waters. In stations EB-1 to EB-5, the general average size of the longer axis of this species is ~\u0026thinsp;130 \u0026micro;m, while in stations DK-1 and DK-2, that average is ~\u0026thinsp;165 \u0026micro;m.\u003c/p\u003e \u003cp\u003eThe results show that despite the highest number of observed measurements in the analyzed stations being between 90 and 180 \u0026micro;m (Figs.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e), the biggest dimensions of \u003cem\u003eA. glomeratum\u003c/em\u003e tests (between 200 and 320 \u0026micro;m) were recorded only in the deepest stations (DK-1 and DK-2), where the highest standard deviation values were found too. The statistical results (Fig.\u0026nbsp;5) show that station DK-2 is significantly different from the others but similar to station DK-1. The cluster analysis results (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eB) also suggest that the highest mean and maximum values of \u003cem\u003eA. glomeratum\u003c/em\u003e sizes are associated with finer-grained sediments found in the deeper stations.\u003c/p\u003e \u003cp\u003e \u003cem\u003eAdercotrima glomeratum\u003c/em\u003e is the most abundant species in the study area, mainly in the composition of the living assemblages from the upper 2 cm of surface sediments, where it is frequently the dominant species (Passos, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). This agrees with the fact that it is an opportunistic species with a great capacity to colonize environments and with wide tolerance to environmental variability, having a cosmopolitan character and generalist behavior (Fontanier et al., 2002; Ernst and Zwaan, 2004; Bella et al., 2016).\u003c/p\u003e \u003cp\u003eMany studies show that the difference in the size of tests of foraminifera species is related to depth (Theyer, 1969; Corliss, 1979; Loubere et al., 1988; Majewski and Pawlowski, 2010; Gooday et al., 2017). For instance, \u003cem\u003eGlobocassidulina\u003c/em\u003e sp. presented tests with reduced size in deeper regions of the Pacific Ocean, Southeast Indian Ocean, and North Atlantic (Theyer, 1969; Corliss, 1979; Loubere et al., 1988). Majewski and Pawlowski (2010) observed that, in the Antarctic Peninsula, some \u003cem\u003eGlobocassidulina\u003c/em\u003e spp. showed reduced sizes in deeper regions. These studies have shown a tendency for many species of foraminifera (the vast majority with carbonated-tests species) to decrease in size as depth increases.\u003c/p\u003e \u003cp\u003eThe tests of \u003cem\u003eA. glomeratum\u003c/em\u003e analyzed in this study, on the other hand, present an opposite pattern than that reported by the mentioned studies since they tend to show the biggest tests in deeper regions. When we analyze only the studies that have used foraminifera species with agglutinating tests, we can identify that this relationship is inversely proportional to that of calcareous test species. Even though research investigating differences in the size of tests from agglutinating species is rarer, it does show that individuals tend to increase in size according to depth. For example, Theyer (1969) found that \u003cem\u003eCyclammina cancellata\u003c/em\u003e had bigger individuals with more robust walls at a depth of 2000 m, while the individuals of this species found at 500 m were smaller and more fragile. Theyer (1969) deduced that the temperature can be the main factor that controls this pattern. The group of Xenophyophores (agglutinating, monothalamids, giant, and sensitive foraminifera) are found only in deep regions and indicate the ability to adapt to the abyssal areas by increasing the tests (Gooday et al., 2017). These examples suggest that the agglutinating species present systems of adaptation to the deep regions different from that of calcareous tests.\u003c/p\u003e \u003cp\u003eMost studies reported that \u003cem\u003eA. glomeratum\u003c/em\u003e prefers muddy sediments in bottoms that receive phytodetritus from the sea surface (Gooday, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e1988\u003c/span\u003e; Gooday and Turley, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e1990\u003c/span\u003e; Rodrigues et al., 2015). Based on these remarks, we can say that the deepest regions of DP provide a more stable environment for this species' development since muddy substrates are generally related to calm hydrodynamic conditions. This calm and stable environment may allow the individuals to complete their life cycle and reach larger sizes. In addition, the deepest stations show the greatest variation in size, indicating the presence of organisms at different stages of development.\u003c/p\u003e \u003cp\u003eOn the contrary, this work also suggests that, in environments disturbed by strong hydrodynamic conditions or by the deposition of sediments resulting, for example, from iceberg melting, this species has short life cycles and forms populations of smaller individuals. When the environmental conditions are stable, the life cycles of this species may be longer, and the populations may include larger organisms. Thus, the results of this study show that the size of \u003cem\u003eA. glomeratum\u003c/em\u003e in the deep ocean can be an indicator of environmental disturbance or stability.\u003c/p\u003e"},{"header":"6. Conclusion","content":"\u003cp\u003e \u003cem\u003eAdercotrymma glomeratum\u003c/em\u003e is one of the main species in the living assemblages of foraminifera in the deep-sea of Antarctica, where the waters are cold, have salinity below the normal oceanic one and corrosive waters that prevent or hinder calcification of carbonate species. The results of this work show that in these conditions, in areas of the deep ocean subject to environmental disturbance caused by strong currents or by the discharge of sediment from the iceberg melting, for example, the individuals in \u003cem\u003eA. glomeratum\u003c/em\u003e populations are smaller. While in stable areas, this species forms populations of bigger individuals. Thus, the data obtained in this work suggest that the size of A. \u003cem\u003eglomeratum\u003c/em\u003e can be used as a tracer of environmental disturbance or stability in deep-sea areas, such as Antarctica.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eEach author contributed significantly to this study as follows: C.C.P. and W.D. conceived the study and designed the methodology. W.D. conducted the field sampling. C.C.P. performed the laboratory analyses. C.C.P. and M.V.A.M. interpreted the data, wrote the main manuscript text, and prepared the figures and tables. All authors reviewed and approved the final version of the manuscript.This statement replaces any other written within the manuscript and is the one that will be published.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe present work is part of broader research coordinated by Professor Ant\u0026ocirc;nio Carlos Rocha-Campos (in memoriam) from the Institute of Geosciences of the University of S\u0026atilde;o Paulo (IGcUSP) and Professor W\u0026acirc;nia Duleba, from the School of Arts, Sciences and Humanities of University of S\u0026atilde;o Paulo (EACH-USP), about methane emanations related to hydrothermalism (vents and fumaroles) and gas hydrates (cold seeps) located in the Bransfield Strait, Drake and Larsen Platform region (PROANTAR-CNPq Proc. 55036 / 2009-7). The authors would like to thank the Brazilian Antarctic Program (PROANTAR), the Captain and crew of the Navio Polar Maximiano (Marinha do Brasil) for logistical support, and the Coordination of Improvement of Higher Education Personnel (CAPES) for the doctoral fellowship (Camila Cunha Passos). Special thanks to V. D. Solovyov (Institute of Geophysics of National Academy of Science of Ukraine) for the geographical coordinates of the locals rich in hydrate gas and Anderson T. S. Ferreira for the map.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eALVE E. (1995). Benthic foraminiferal responses to estuarine pollution: a review. \u003cem\u003eJournal Foraminiferal Research\u003c/em\u003e, \u003cem\u003e25\u003c/em\u003e(3), 190\u0026ndash;203.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMURRAY, J. W. (2001). Temporal variability in vertical distributions of live (stained) intertidal foraminifera. southern England. \u003cem\u003eJournal of Foraminiferal Research\u003c/em\u003e 31(1): 12\u0026ndash;24. 2001.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAMAO, A. O., QURBAN M.A., KAMINSKI M.A., JOYDAS T.V., MANIKANDAN P.K. and FRONTALINI F (2020). Dataset showing the abundance and distribution of benthic foraminifera in relation to marine sediment parameters from western Arabian Gulf. \u003cem\u003eData in Brief\u003c/em\u003e, \u003cem\u003e28\u003c/em\u003e, 105014.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBELLA L., INGRASSIA M., FREZZA V., CHIOCCI F.L. and MARTORELLI E. (2016). The response of benthic meiofauna to hydrothermal emissions in the Pontine Archipelago. Tyrrhenian Sea (central Mediterranean Basin). \u003cem\u003eJournal of Marine Systems\u003c/em\u003e 164: 53\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBERNHARD J.M., BARRY J.P., BUCK K. and STARCZAK V.R. (2009). Impact of intentionally injected carbon dioxide hydrate on deep-sea benthic foraminiferal survival. \u003cem\u003eGlobal Change Biology\u003c/em\u003e 15: 2078\u0026ndash;2088.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMEDIOLI, F. S. (1991). Morphological Variation of Benthic Foraminiferal tests in response to Changes in Ecological Parameters: a review. \u003cem\u003eJournal Paleontology\u003c/em\u003e, \u003cem\u003e65\u003c/em\u003e(2), 175\u0026ndash;185.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSAURIAU P.G, B. O. U. C. H. E. T. V. M. P., DEBENAY, J. P., \u0026amp; MERMILLOD-BLONDIN F., S. C. H. M. I. D. T. S., AMIARD J.C. and DUPAS. B (2009). Influence of the mode of macrofauna-mediated bioturbation on the vertical distribution of living benthic foraminifera: First insight from axial tomodensitometry. \u003cem\u003eJournal of Experimental Marine Biology and Ecology\u003c/em\u003e, \u003cem\u003e371\u003c/em\u003e, 20\u0026ndash;33.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBUZAS, M. A. (1974). Vertical distribution of Ammobaculites in the Rhode River. Maryland. \u003cem\u003eJournal of Foraminiferal Research\u003c/em\u003e, \u003cem\u003e4\u003c/em\u003e(3), 144\u0026ndash;147.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBUZAS, M. A. (1997). Vertical distribution of Foraminifera in the Indian River. Florida. \u003cem\u003eJournal of Foraminiferal Research\u003c/em\u003e, \u003cem\u003e7\u003c/em\u003e(3), 234\u0026ndash;237.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEL-KAHAWY, C. E. S. B. R. O. N. F. G. E. S. L. I. N. E. J. O. R. I. S. S. E. N. F. J. D. E. L. G. A. R. D. M. L. C. H. A. R. R. I. E. A. U. L. D. E. F. L. A. N. D. R. E. D., EL-SHAFEIY, R. M. and, \u0026amp; HELAL, S. A. (2018). Morphological deformities of benthic foraminifera in response to nearshore pollution of the Red Sea. Egypt. \u003cem\u003eEnvironmental Monitoring Assessment\u003c/em\u003e, \u003cem\u003e190\u003c/em\u003e, 312.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCORLISS B. (1979). Size variation in the deep-sea benthonic foraminifer \u003cem\u003eGlobocassidulina subglobosa\u003c/em\u003e (Brady) in the Southeast Indian Ocean. \u003cem\u003eJournal Foraminiferal Research\u003c/em\u003e 9: 50\u0026ndash;60.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eERNST S. and ZWAAN B. (2004). Effects of experimentally induced raised levels of organic flux and oxygen depletion on a continental slope benthic foraminiferal community. \u003cem\u003eDeep-Sea Research I\u003c/em\u003e 51: 1709\u0026ndash;1739.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLE, E. R. N. S. T. S. R. M. O. R. V. A. N. J. G. E. S. L. I. N. E., BIHAN, A., \u0026amp; JORISSEN, F. J. (2006). Benthic foraminiferal response to experimentally induced Erika oil pollution. \u003cem\u003eMarine Micropaleontology\u003c/em\u003e, \u003cem\u003e60\u003c/em\u003e, 76\u0026ndash;93.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFINGER, K. L., \u0026amp; LIPPS, J. H. (1981). Foraminiferal decimation and repopulation in an active volcanic caldera. \u003cem\u003eDeception Island Antarctica Micropaleontology\u003c/em\u003e, \u003cem\u003e27\u003c/em\u003e(2), 111\u0026ndash;139.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFONTANIER C., JORISSEN F.J., LICARI L., ALEXANDRE A., ANSCHUTZ P. and CARBONEL P. (2002). Live benthic foraminiferal faunas from the Bay of Biscay: faunal density. composition. and microhabitats. \u003cem\u003eDeep-Sea Research I\u003c/em\u003e 49: 751\u0026ndash;785.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFRONTALINI F. and COCCIONI R. (2008). Benthic foraminifera for heavy metal pollution monitoring: A case study from the central Adriatic Sea coast of Italy. \u003cem\u003eEstuarine Coastal and Shelf Science\u003c/em\u003e 76: 404\u0026ndash;417.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGARC\u0026Iacute;A, M. A., R\u0026Iacute;OS A.F., C. A. S. T. R. O. C. G., \u0026amp; DOVAL, M. D., ROS\u0026Oacute;N G., GOMIS D. and L\u0026Oacute;PEZ O (2002). Water masses ans distribution of physico-chemical properties in the Western Bransfield Strait and Gerlache Strait during Austral Summer 1995/96. \u003cem\u003eDeep-Sea Research II\u003c/em\u003e, \u003cem\u003e49\u003c/em\u003e(4\u0026ndash;5), 585\u0026ndash;602.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGOODAY A. J., HOLZMANN M., CAULLE C., GOINEAU A., KAMENSKAYA O., WEBER A. A. T. and PAWLOWSKI J. (2017). Giant protists (xenophyophores, Foraminifera) are exceptionally diverse in parts of the abyssal eastern Pacific licensed for polymetallic nodule exploration. \u003cem\u003eBiological Conservation\u003c/em\u003e 207:106\u0026ndash;116.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGOODAY, A. J. (1988). A response by benthic foraminifera to phytodetritus deposition in the deep sea. \u003cem\u003eNature\u003c/em\u003e, \u003cem\u003e332\u003c/em\u003e, 70\u0026ndash;73.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGOODAY, A. J., \u0026amp; TURLEY, C. M. (1990). Responses by benthic organisms to inputs of organic material to the ocean floor: a review. \u003cem\u003ePhilosophical Transactions of The Royal Society\u003c/em\u003e, \u003cem\u003e331\u003c/em\u003e, 119\u0026ndash;138.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNOWLIN, W. D. (1978). The basin waters of Bransfield Strait. \u003cem\u003eJournal of Physical Oceanography\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e, 258\u0026ndash;267.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHARLOFF J. and MACKENSEN A. (1997). Recent benthic foraminiferal associations and ecology of the Scotia Sea and Argentine Basin. \u003cem\u003eMarine Micropaleontology\u003c/em\u003e 31: 1\u0026ndash;29.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eISHMAN, S. E., \u0026amp; DOMACK, E. W. (2004). Oceanographic controls on benthic foraminifers from the Bellingshausen margin of the Antarctic Peninsula. \u003cem\u003eMarine Micropaleontology\u003c/em\u003e, \u003cem\u003e24\u003c/em\u003e, 119\u0026ndash;155.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJ\u0026Eacute;Z\u0026Eacute;QUEL, V. M. (2016). Locomotion speed of the benthic foraminifer Ammonia tepida exposed to different nitrogen and carbono sources. \u003cem\u003eJournal of Sea Research\u003c/em\u003e, \u003cem\u003e118\u003c/em\u003e, 52\u0026ndash;58.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJONES, R. W. (2013). \u003cem\u003eForaminifera ans their Application\u003c/em\u003e (p. 263). Cambridge. University.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJOUGHIN I. and ALLEY R.B. (2011). Stability of the Weste Antarctic ice she in a warming world. \u003cem\u003eNature Geocience\u003c/em\u003e 4: 506\u0026ndash;513.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKURBJEWEIT F., SCHMIEDL G., SCHIEBEL R., HEMLEBEN CH., PFANNKUCHE O., WALLMANN K. and SCH\u0026Auml;FER P. (2000). Distribution. biomass and diversity of benthic foraminifera in relation to sediment geochemistry in the Arabian Sea. \u003cem\u003eDeep-Sea Research II\u003c/em\u003e 47: 2913\u0026ndash;2955.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLE, C. A. D. R. E. V., \u0026amp; DEBENAY, J. P. (2006). Morphological and cytological response of Ammonia (foraminifera) to copper contamination: implication for the use of foramin\u0026iacute;feras bioindicators of pollution. \u003cem\u003eEnvironmental Pollution\u003c/em\u003e, \u003cem\u003e142\u003c/em\u003e, 304\u0026ndash;317.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLOUBERE P., BANONIS G. and JAKIEL R. (1988). \u003cem\u003eGlobocassidulina Subglobosa\u003c/em\u003e (Brady): Environmental control of species abundance and specimen test size. \u003cem\u003eJournal Foraminiferal Research\u003c/em\u003e 18 (1): 6\u0026ndash;15.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFIITTERER, D. K. (1990). Benthic Foraminiferal assemblages from the eastern Weddell Sea between 68 and 73\u0026deg;S: Distribution. ecology and fossilization potential. \u003cem\u003eMarine Micropaleontology\u003c/em\u003e, \u003cem\u003e16\u003c/em\u003e, 241\u0026ndash;283.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMAJEWSKI W. and PAWLOWSKI J. (2010). Morphologic and molecular diversity of the foraminiferal genus Globocassidulina in Admiralty Bay, King George Island. \u003cem\u003eAntarctic Science\u003c/em\u003e 22(3):271\u0026ndash;281.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMARTINS, M. V. A., LAUT L.L.M., F. R. O. N. T. A. L. I. N. I. F., FONSECA M.C.M., S. E. Q. U. E. I. R. A. C. R. O. D. R. I. G. U. E. S. R., DELAVY, B. E. R. G. A. M. A. S. C. H. I. S. P. E. R. E. I. R. A. E., \u0026amp; FIGUEIREDOJR, F. P. (2016). Controlling factors on the abundance. diversity and size of living benthic foraminifera in the NE sector of Guanabara Bay (Brazil). \u003cem\u003eJournal of Sedimentary Environments\u003c/em\u003e, \u003cem\u003e1\u003c/em\u003e(4), 393\u0026ndash;410.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMILKOV, A. V. (2000). Worldwide distribution of submarine mud volcanoes and associated gas hydrates. \u003cem\u003eMarine Geology\u003c/em\u003e, \u003cem\u003e167\u003c/em\u003e(1\u0026ndash;2), 29\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMURRAY, J. W. (1991). \u003cem\u003eEcology and paleoecology of benthic foramin\u0026iacute;fera\u003c/em\u003e (397pp.). Logman Scientific and Technical.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMURRAY, J. W. (2006). \u003cem\u003eEcology and applications of benthic foramin\u0026iacute;fera\u003c/em\u003e (p. 426). Cambridge University Press.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePASSOS, C. C. (2019). \u003cem\u003eEcologia de foramin\u0026iacute;feros bent\u0026ocirc;nicos das regi\u0026otilde;es da Passagem do Drake e Ilha de Marambio. Pen\u0026iacute;nsula Ant\u0026aacute;rtica.\u003c/em\u003e PhD Thesis (Postgraduate Program in Sustainability). School of Arts. Sciences and Humanities at the University of S\u0026atilde;o Paulo. Sao Paulo. 261pp.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eROBERTSON R., VISBECK M., GORDON A.L. and AHRBACH E. (2002). Long-term temperature trends in the deep waters of the Weddell Sea. \u003cem\u003eDeep-Sea Research II\u003c/em\u003e 49: 4791\u0026ndash;4806. JOUGHIN. I.; ALLEY. R. B. 2011. Stability of the West Antarctic ice sheet in a warming world. \u003cem\u003eNature Geocience\u003c/em\u003e 4:506\u0026ndash;513.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEICHLER, R. O. D. R. I. G. U. E. S. A. R. P.P.B. and EICHLER B.B (2013). Foraminifera in two inlets fed by a tidewater glacier. \u003cem\u003eKing George Island Antarctic Peninsula Journal Foraminiferal Research\u003c/em\u003e, \u003cem\u003e43\u003c/em\u003e(3), 209\u0026ndash;220.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHERN\u0026Aacute;NDEZ-ARENCIBIAC M., S. A. N. G. R. \u0026Agrave;. P. S. T. E. G. N. E. R. B. A., \u0026amp; MARRERO-D\u0026Iacute;AZC A., S. A. L. I. N. A. S. A. C. AGUIAR-GONZ\u0026Aacute;LEZD B., HENR\u0026Iacute;QUEZ-PASTENEE C. and MOURI\u0026Ntilde;O-CARBALLIDO B. 2017. The Bransfield Gravity current. \u003cem\u003eDeep-Sea Research I\u003c/em\u003e 119: 1\u0026ndash;15.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSANTINI, M. F. (2011). \u003cem\u003eEstrutura termohalina e massas d'\u0026aacute;gua na vizinhan\u0026ccedil;a da Pen\u0026iacute;nsula Ant\u0026aacute;rtica a partir de dados in situ coletados por elefantes-marinhos do sul (Mirounga leonina).\u003c/em\u003e Master's Dissertation (Post-Graduate Program in Physical Oceanography). Oceanographic Institute. University of Sao Paulo. S\u0026atilde;o Paulo. 93pp.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSCH\u0026Ouml;NFELD J., ALVE E., GESLIN E., JORISSEN F., KORSUN S. and SPEZZAFERRI S. (2012). The FOBIMO (FOraminiferal BIo-MOnitoring) initiative - Towards a standardized protocol for soft-bottom benthic foraminiferal monitoring studies. \u003cem\u003eMarine Micropaleontology\u003c/em\u003e 94(95): 1\u0026ndash;13.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMEDIOLI, S. C. O. T. T. D. B. F.S. and, \u0026amp; SCHAFER, C. T. (2001). \u003cem\u003eMonitoring in coastal environments using foraminifera and thecamoebian indicators\u003c/em\u003e (p. 192). Cambridge University Press.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSEMENSATTOJR, D. L., \u0026amp; DIAS-BRITO D (2007). Alternative saline solutions to float foraminiferal tests. \u003cem\u003eJournal of Foraminiferal Research\u003c/em\u003e, \u003cem\u003e37\u003c/em\u003e(3), 265\u0026ndash;269.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSHEPARD, F. P. (1954). Nomenclature based on sand-sily-clay ration. \u003cem\u003eJournal od Sedimentary Petrology\u003c/em\u003e, \u003cem\u003e24\u003c/em\u003e(3), 151\u0026ndash;158.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKORCHAGIN I.N., S. O. L. O. V. Y. O. V. V. D. B. A. K. H. M. U. T. O. V. V. G., LEVASHOV S.P., YAKYMCHUK N.A. and, \u0026amp; BOZHEZHA, D. N. (2011). Gas Hydrates Accumulations on the South Shetland Continental Margin: New Detection Possibilities. \u003cem\u003eJournal of Geological Research\u003c/em\u003e, \u003cem\u003e2011\u003c/em\u003e, 1\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSTEFANOUDIS P.V., SCHIEBEL R., MALLET R., DURDEN J.M., BETT B.J., and GOODAY A.J. (2016). Agglutination of benthic foraminifera in relation to mesoscalebathymetric features in the abyssal NE Atlantic (Porcupine Abyssal Plain). \u003cem\u003eMarine Micropaleontology\u003c/em\u003e 123: 12\u0026ndash;28.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSUGUIO K. \u003cem\u003eIntrodu\u0026ccedil;\u0026atilde;o \u0026agrave; sedimentologia.\u003c/em\u003e (1973). S\u0026atilde;o Paulo, Edgard Bl\u0026uuml;cher. 165pp.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTHEYER F. (1969). Size-Depth Variation in Foraminifer Cyclammina Cancellata Brady from Peru-Chile Trench Area. \u003cem\u003eAdvancing the Word of Petroleum Geoscience Bulletin\u003c/em\u003e 53 (2): 466\u0026ndash;467.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTHORPE, S. E., HEYWOOD K.J., BRANDON M.A. and, \u0026amp; STEVENS, D. P. (2002). Variability of the southern Antarctic Circumpolar Current Front north of South Georgia. \u003cem\u003eJournal of Marine Systems\u003c/em\u003e, \u003cem\u003e451\u003c/em\u003e, 87\u0026ndash;105.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWALTON, W. R. (1952). Techniques for recognition of living foramin\u0026iacute;fera. \u003cem\u003eCushman Foundation Research\u003c/em\u003e, \u003cem\u003e3\u003c/em\u003e(2), 56\u0026ndash;64.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWOLLENBURG, J. E. and KUHNT W (2000). The response of benthic Foraminifers to carbon flux and primary production in the Arctic Ocean. \u003cem\u003eMarine Micropaleontology\u003c/em\u003e, \u003cem\u003e40\u003c/em\u003e, 189\u0026ndash;231.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYANKO V., AHMAD. M. and KAMINSKI. M. (1998). Morphological deformities of benthic foraminiferal tests in response to pollution by heavy metals: implications for pollution monitoring. \u003cem\u003eJournal Foraminiferal Research\u003c/em\u003e 28(3): 177\u0026ndash;200.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDORLAND, R. D. (2006). The western boundary current in the Bransfield Strait. Antarctica. \u003cem\u003eDeep-Sea Research I\u003c/em\u003e, \u003cem\u003e53\u003c/em\u003e, 1244\u0026ndash;1252.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 - Collection Dates, water depth (in meters) and geographic coordinates of the sampling station in the Drake Passage during OPERANTAR XXXI and XXXII.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"548\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.453382084095065%\"\u003e\n \u003cp\u003e\u003cstrong\u003eOPERANTAR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.625228519195613%\"\u003e\n \u003cp\u003e\u003cstrong\u003eCores\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.442413162705668%\"\u003e\n \u003cp\u003e\u003cstrong\u003eSampling date\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.926873857404022%\"\u003e\n \u003cp\u003e\u003cstrong\u003eWater depth\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e(m)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.184643510054844%\"\u003e\n \u003cp\u003e\u003cstrong\u003eLatitude\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.36745886654479%\"\u003e\n \u003cp\u003e\u003cstrong\u003eLongitude\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.453382084095065%\"\u003e\n \u003cp\u003e\u003cstrong\u003eXXXI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.625228519195613%\"\u003e\n \u003cp\u003eEB-1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.442413162705668%\"\u003e\n \u003cp\u003e24/01/2013\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.926873857404022%\"\u003e\n \u003cp\u003e490\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.184643510054844%\"\u003e\n \u003cp\u003e61.430017 S\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.36745886654479%\"\u003e\n \u003cp\u003e56.950700 W\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.453382084095065%\"\u003e\n \u003cp\u003e\u003cstrong\u003eXXXI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.625228519195613%\"\u003e\n \u003cp\u003eEB-2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.442413162705668%\"\u003e\n \u003cp\u003e24/01/2013\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.926873857404022%\"\u003e\n \u003cp\u003e492\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.184643510054844%\"\u003e\n \u003cp\u003e61.425683 S\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.36745886654479%\"\u003e\n \u003cp\u003e56.954767 W\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.453382084095065%\"\u003e\n \u003cp\u003e\u003cstrong\u003eXXXI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.625228519195613%\"\u003e\n \u003cp\u003eEB-3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.442413162705668%\"\u003e\n \u003cp\u003e24/01/2013\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.926873857404022%\"\u003e\n \u003cp\u003e483\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.184643510054844%\"\u003e\n \u003cp\u003e61.419317 S\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.36745886654479%\"\u003e\n \u003cp\u003e56.961167 W\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.453382084095065%\"\u003e\n \u003cp\u003e\u003cstrong\u003eXXXI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.625228519195613%\"\u003e\n \u003cp\u003eEB-4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.442413162705668%\"\u003e\n \u003cp\u003e24/01/2013\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.926873857404022%\"\u003e\n \u003cp\u003e472\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.184643510054844%\"\u003e\n \u003cp\u003e61.419617 S\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.36745886654479%\"\u003e\n \u003cp\u003e56.949367 W\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.453382084095065%\"\u003e\n \u003cp\u003e\u003cstrong\u003eXXXI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.625228519195613%\"\u003e\n \u003cp\u003eEB-5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.442413162705668%\"\u003e\n \u003cp\u003e24/01/2013\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.926873857404022%\"\u003e\n \u003cp\u003e486\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.184643510054844%\"\u003e\n \u003cp\u003e61.421050 S\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.36745886654479%\"\u003e\n \u003cp\u003e56.932167 W\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.453382084095065%\"\u003e\n \u003cp\u003e\u003cstrong\u003eXXXII\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.625228519195613%\"\u003e\n \u003cp\u003eDK-1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.442413162705668%\"\u003e\n \u003cp\u003e17/01/2014\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.926873857404022%\"\u003e\n \u003cp\u003e3700\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.184643510054844%\"\u003e\n \u003cp\u003e61.074567 S\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.36745886654479%\"\u003e\n \u003cp\u003e57.883917 W\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"16.453382084095065%\"\u003e\n \u003cp\u003e\u003cstrong\u003eXXXII\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.625228519195613%\"\u003e\n \u003cp\u003eDK-2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.442413162705668%\"\u003e\n \u003cp\u003e17/01/2014\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.926873857404022%\"\u003e\n \u003cp\u003e3850\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.184643510054844%\"\u003e\n \u003cp\u003e61.072671 S\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.36745886654479%\"\u003e\n \u003cp\u003e57.880893 W\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 2 - Percentage of sediment fractions according to Wentworth (1922) and classification of the sediment according to Shepard (1954) in the analyzed stations. Legend: Sand F \u0026ndash; sand fractions (63-2000 \u0026micro;m); Fine F \u0026ndash; fine fraction (\u0026lt;63 \u0026micro;m); Tsand (%) \u0026ndash; total percentage of sand fractions (63-2000 \u0026micro;m); Fines (%) \u0026ndash; total percentage of fine fractions (\u0026lt;63 \u0026micro;m); Granules (%) \u0026ndash; sediment faction between 2000-4000 \u0026micro;m; VCSF \u0026ndash; very coarse sand fraction (1000-2000 \u0026micro;m); CSF - coarse sand fraction (500-1000 \u0026micro;m); MSF - \u0026nbsp;medium sand fraction (250-500 \u0026micro;m); FSF \u0026ndash; fine sand fraction (125-250 \u0026micro;m); VFSF \u0026ndash; very fine sand fraction (63-125 \u0026micro;m); silt \u0026ndash; silt fraction (fine sand fraction (2-63 \u0026micro;m); clay \u0026ndash; clay fraction (\u0026lt;2 \u0026micro;m);\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"597\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.958123953098827%\" colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eStations/SF\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEB-1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEB-2\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEB-3\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEB-4\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEB-5\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e\u003cstrong\u003eDK-1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e\u003cstrong\u003eDK-2\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.958123953098827%\" colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eGranules (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e9.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e3.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e2.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e9.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e4.85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e0.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e0.00\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.23785594639866%\" rowspan=\"5\"\u003e\n \u003cp\u003e\u003cstrong\u003eSand F (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003eVCSF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e10.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e4.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e4.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e8.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e8.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e0.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e0.00\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003eCSF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e9.77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e18.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e9.80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e17.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e10.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e0.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e0.00\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003eMSF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e16.18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e20.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e22.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e20.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e15.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e0.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003eFSF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e25.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e20.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e27.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e22.19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e24.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e0.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e1.02\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003eVFSF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e12.19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e13.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e12.60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e6.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e15.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e7.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e4.92\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.23785594639866%\" rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eFine F (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003eSilt\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e10.42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e11.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e11.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e8.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e10.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e80.19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e83.81\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003eClay\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e6.79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e7.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e8.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e7.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e9.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e12.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.5%\"\u003e\n \u003cp\u003e10.17\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.958123953098827%\" colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eTsand (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e73.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e77.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e77.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e74.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e75.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e7.66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e6.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.958123953098827%\" colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eFines (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e17.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e18.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e20.32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e16.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e19.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e92.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003e93.99\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.958123953098827%\" colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eClassification\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003eSand\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003eSand\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003eSand\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003eSand\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003eSand\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003eSilt\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.720268006700168%\"\u003e\n \u003cp\u003eSilt\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 3 - Size ranges of specimens of \u003cem\u003eA. glomeratum\u003c/em\u003e found in the analyzed stations. The number of specimens and the percentage (in brackets) of the total number of analyzed individuals (40) were presented for each size.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"98%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"20%\"\u003e\n \u003cp\u003e\u003cstrong\u003eStations/\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eCategory\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEB-1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEB-2\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEB-3\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEB-4\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEB-5\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e\u003cstrong\u003eDK-1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e\u003cstrong\u003eDK-2\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20%\"\u003e\n \u003cp\u003e\u003cstrong\u003eTotal measured\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003especimens\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20%\"\u003e\n \u003cp\u003e\u003cstrong\u003eSmall tests\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(\u0026lt;125\u0026micro;m)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e12 (30%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e20 (50%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e26 (65%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e12 (30%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e25 (62.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e3 (7.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e10 (25%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20%\"\u003e\n \u003cp\u003e\u003cstrong\u003eMedium tests\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(125-250\u0026micro;m)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e28 (70%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e20 (50%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e14 (35%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e28 (70%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e15 (37.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e34 (85%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e27 (67.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20%\"\u003e\n \u003cp\u003e\u003cstrong\u003eLarge tests\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(250-500 \u0026micro;m)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e3 (7.5 %)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e3 (7.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20%\"\u003e\n \u003cp\u003e\u003cstrong\u003eVery large tests\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(\u0026gt;500\u0026micro;m)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.526315789473685%\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.631578947368421%\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 4.\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"455\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.604395604395604%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e\u003cstrong\u003eb*\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e\u003cstrong\u003eStd.Err.\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e\u003cstrong\u003eb\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e\u003cstrong\u003eStd.Err.\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e\u003cstrong\u003et(6)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.604395604395604%\"\u003e\n \u003cp\u003e\u003cstrong\u003eIntercept\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e-0.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e0.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e-0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e0.83\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.604395604395604%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEB-1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e-0.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e0.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e-0.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e0.77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e-0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e0.52\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.604395604395604%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEB-2\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e-0.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e-0.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e0.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e-0.88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.065934065934066%\"\u003e\n \u003cp\u003e0.40\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.604395604395604%\"\u003e\n 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Environments","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Sediment, Benthic Foraminifera, Living populations, Deep Sea, Bio-indicator","lastPublishedDoi":"10.21203/rs.3.rs-4578446/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4578446/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe Drake Passage is a highly hydrodynamic region that is difficult to navigate due to adverse weather conditions and intense surface currents. This study investigates how the bottom hydrodynamic regime influences the size of foraminiferal tests on the Antarctic Peninsula. For this, the species \u003cem\u003eAdercotryma glomeratum\u003c/em\u003e (an agglutinated species of foraminifera) was chosen, as it was the only species abundant in the seven selected stations. Five stations (EB-1 to EB-5) are located in a region with a depth of ~\u0026thinsp;480 m and two in a deep area of ~\u0026thinsp;3,800 m (DK-1 and DK-2). All the tests were individually measured along their long axis and classified according to size. The most frequently recorded size range of \u003cem\u003eA. glomeratum\u003c/em\u003e varied between \u0026asymp;\u0026thinsp;90\u0026ndash;180 \u0026micro;m. The average test size and standard deviation were lower at stations EB-1 to EB-5, with coarser-grained sediments. The cluster analysis based on grain size, morphometric data of \u003cem\u003eA. glomeratum\u003c/em\u003e, and depth shows that the largest sizes of this species tend to occur in fine-grained sediments at stations DK-1 and DK-2. The fine-grained sediments at stations DK-1 and DK-2 indicate the presence of calmer bottom conditions. These results suggest that in deep-sea environments, the stable areas, under calmer hydrodynamic conditions, enable longer life cycles of living foraminifera and the development of populations with bigger individuals, namely of \u003cem\u003eA. glomeratum.\u003c/em\u003e The data obtained in this work suggest that the size of \u003cem\u003eA. glomeratum\u003c/em\u003e populations can be used as an indicator of the stability/instability of the environment. Thus, the size of the individuals that make up the populations of \u003cem\u003eA. glomeratum\u003c/em\u003e, and probably other foraminiferal species, can be used in paleoenvironmental reconstructions as a trace of disturbances or environmental stability in deep-sea settings, such as that of the Southern Ocean.\u003c/p\u003e","manuscriptTitle":"Developing a palaeoceanographic proxy based on the dimensions of Adercotryma glomeratum populations: a case study in Drake Passage region (Antarctic Peninsula)","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-07-18 15:26:05","doi":"10.21203/rs.3.rs-4578446/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-07-11T18:14:36+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-07-11T16:03:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"13920221119932445805969234785555905082","date":"2024-07-08T13:11:56+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-06-28T16:32:53+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"106614231224238237510891326435415381810","date":"2024-06-21T16:20:09+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-06-19T11:41:34+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-06-19T08:40:23+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-06-14T08:11:10+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Sedimentary Environments","date":"2024-06-13T22:34:11+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-sedimentary-environments","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jsev","sideBox":"Learn more about [Journal of Sedimentary Environments](https://link.springer.com/journal/43217)","snPcode":"43217","submissionUrl":"https://submission.nature.com/new-submission/43217/3","title":"Journal of Sedimentary Environments","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"985ce6ff-b8c9-4e10-aff5-0504796adbc9","owner":[],"postedDate":"July 18th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-01-20T15:59:55+00:00","versionOfRecord":{"articleIdentity":"rs-4578446","link":"https://doi.org/10.1007/s43217-024-00214-5","journal":{"identity":"journal-of-sedimentary-environments","isVorOnly":false,"title":"Journal of Sedimentary Environments"},"publishedOn":"2025-01-17 15:57:04","publishedOnDateReadable":"January 17th, 2025"},"versionCreatedAt":"2024-07-18 15:26:05","video":"","vorDoi":"10.1007/s43217-024-00214-5","vorDoiUrl":"https://doi.org/10.1007/s43217-024-00214-5","workflowStages":[]},"version":"v1","identity":"rs-4578446","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4578446","identity":"rs-4578446","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}