Pub Date : 2025-11-01Epub Date: 2025-09-22DOI: 10.1016/j.dsr.2025.104594
Mari H. Eilertsen , Marte L.B. Klemetsdal , Jon A. Kongsrud , Anne Helene S. Tandberg , Tom Alvestad , Brenda L. Esteban Vazquez , Alessandra Savini , Claudio Argentino , Giuliana Panieri
Cold seeps are common seafloor features on Arctic continental margins, but the cold seep fauna in the region has mainly been characterized from sites on the continental shelf or upper slope (<800 m). Here, we characterize the fauna of two deep-water cold seeps on the Vestnesa (1300 m) and Svyatogor Ridges (1900 m) based on morphological analyses and DNA barcoding. The Svyatogor Ridge system has been hypothesized to represent a hybrid system with processes resembling both hydrothermal vents and cold seeps, however, until now, it had not been tested whether its fauna shows any similarity to regional hydrothermal vent fauna. The present study documents a clearly specialised fauna at both seeps with seven putatively new and seep-specialised species recorded as well as eight species shared with the sedimented hydrothermal vent Loki's Castle approximately 540 km further south on the Mohns Ridge. The dataset presented illustrates a close connection between vent and seep faunas in the Arctic, presumably driven by the close geographic proximity of vents and seeps and the presence of intermediate habitats such as sedimented vents.
{"title":"Faunal communities of Arctic deep-water methane seeps are specialised with links to hydrothermal vents","authors":"Mari H. Eilertsen , Marte L.B. Klemetsdal , Jon A. Kongsrud , Anne Helene S. Tandberg , Tom Alvestad , Brenda L. Esteban Vazquez , Alessandra Savini , Claudio Argentino , Giuliana Panieri","doi":"10.1016/j.dsr.2025.104594","DOIUrl":"10.1016/j.dsr.2025.104594","url":null,"abstract":"<div><div>Cold seeps are common seafloor features on Arctic continental margins, but the cold seep fauna in the region has mainly been characterized from sites on the continental shelf or upper slope (<800 m). Here, we characterize the fauna of two deep-water cold seeps on the Vestnesa (1300 m) and Svyatogor Ridges (1900 m) based on morphological analyses and DNA barcoding. The Svyatogor Ridge system has been hypothesized to represent a hybrid system with processes resembling both hydrothermal vents and cold seeps, however, until now, it had not been tested whether its fauna shows any similarity to regional hydrothermal vent fauna. The present study documents a clearly specialised fauna at both seeps with seven putatively new and seep-specialised species recorded as well as eight species shared with the sedimented hydrothermal vent Loki's Castle approximately 540 km further south on the Mohns Ridge. The dataset presented illustrates a close connection between vent and seep faunas in the Arctic, presumably driven by the close geographic proximity of vents and seeps and the presence of intermediate habitats such as sedimented vents.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"225 ","pages":"Article 104594"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-08-06DOI: 10.1016/j.dsr.2025.104572
Júlia R. Martins , Michael M. Mincarone , Arnaud Bertrand , Camila Artana , Flávia Lucena-Frédou , Ariane Koch-Larrouy , Rayssa S. Lima , Leandro N. Eduardo
Lanternfishes (Myctophidae) are among the most abundant vertebrates globally, playing critical roles in carbon transport, nutrient recycling, and trophic structuring of pelagic ecosystems. However, they remain poorly understood and are increasingly impacted by anthropogenic activities. Here we investigated how the plume of the world's largest river, the Amazon, shapes the diversity and assemblage structure of lanternfishes. To this end, we conducted an integrative characterization of the taxonomic diversity, distribution, and abundance of 2916 lanternfish specimens, representing 31 species, collected during the dry season (August–September 2021) across areas with varying levels of Amazon River plume influence. Based on a classification of relative importance, five species were classified as abundant and frequent, while the remaining species were predominantly classified as either scarce and frequent (nine species) or scarce and rare (17 species). In regard to vertical distribution, at least 20 of the 31 species were detected at night in epipelagic waters (0–200 m), displaying four distinct broad patterns of vertical migration and distribution. We showed that, while the Amazon Plume appears to influence lanternfish species richness and size distribution, depth is the primary variable explaining the structuring of lanternfish assemblages. Moreover, while diversity appears to be similar to other tropical regions of the Atlantic Ocean, there is a noticeable dominance of certain species, suggesting that the hydrographic structure and nutrient input from the Amazon River may favour specific species.
{"title":"Influence of the Amazon River plume on the biodiversity and assemblage structure of lanternfishes (Myctophidae)","authors":"Júlia R. Martins , Michael M. Mincarone , Arnaud Bertrand , Camila Artana , Flávia Lucena-Frédou , Ariane Koch-Larrouy , Rayssa S. Lima , Leandro N. Eduardo","doi":"10.1016/j.dsr.2025.104572","DOIUrl":"10.1016/j.dsr.2025.104572","url":null,"abstract":"<div><div>Lanternfishes (Myctophidae) are among the most abundant vertebrates globally, playing critical roles in carbon transport, nutrient recycling, and trophic structuring of pelagic ecosystems. However, they remain poorly understood and are increasingly impacted by anthropogenic activities. Here we investigated how the plume of the world's largest river, the Amazon, shapes the diversity and assemblage structure of lanternfishes. To this end, we conducted an integrative characterization of the taxonomic diversity, distribution, and abundance of 2916 lanternfish specimens, representing 31 species, collected during the dry season (August–September 2021) across areas with varying levels of Amazon River plume influence. Based on a classification of relative importance, five species were classified as abundant and frequent, while the remaining species were predominantly classified as either scarce and frequent (nine species) or scarce and rare (17 species). In regard to vertical distribution, at least 20 of the 31 species were detected at night in epipelagic waters (0–200 m), displaying four distinct broad patterns of vertical migration and distribution. We showed that, while the Amazon Plume appears to influence lanternfish species richness and size distribution, depth is the primary variable explaining the structuring of lanternfish assemblages. Moreover, while diversity appears to be similar to other tropical regions of the Atlantic Ocean, there is a noticeable dominance of certain species, suggesting that the hydrographic structure and nutrient input from the Amazon River may favour specific species.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"225 ","pages":"Article 104572"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-23DOI: 10.1016/j.dsr.2025.104598
Tanja Stratmann , Erik Simon-Lledó , Marcel T.J. van der Meer , Magdalini Christodoulou , Sven Rossel , Ana Colaço
Abyssal seascapes represent over 50 % of the Planet's surface, but the life history traits of fauna present in these ecosystems remain poorly understood. Ophiuroidea constitute about one third of the invertebrate megabenthos assemblage between 3800 m and 4800 m water depth in the Clarion-Clipperton Fracture Zone (CCZ); Asteroidea are present in lower densities. We hypothesize that (1) Ophiuroidea, Xenophyophoroidea, and Hexactinellida have a predator-prey relationship, where Ophiuroidea feed on foraminifera- and sponge-derived organic matter (OM). (2) Ophiuroidea have a reduced dependency on fresh phytodetritus. (3) Brisingida (order of Asteroidea), often cling to stalks to have easier access to particulate OM sinking to the seafloor.
To test these three hypotheses, we combined bulk and compound-specific stable isotope analyses of fauna (Ophiuroidea, Asteroidea) and sediments with analyses of seafloor images from the eastern CCZ.
All investigated Echinodermata species had a high trophic level. Phospholipid-derived fatty acids (PLFAs) used as biomarkers suggest that Silax daleus consumes sedimentary detritus that is processed by its gut microbiome. Ophiacantha cosmica is likely a top consumer or scavenger, Ophiosphalma glabrum is an opportunistic omnivore ingesting phytodetritus, bacteria, Crustacea, and Foraminifera, while Ophiuroglypha cf. polyacantha (sp. 6) is a more selective omnivore. Freyella benthophila sits mostly on stalks of Hexactinellida and uses this elevated position to catch phytodetritus and zooplankton. Freyastera cf. tuberculata, in comparison, sits mostly on polymetallic nodules from where it preys upon Crustacea moving on the sediment surface. We confirmed that Ophiuroidea are less dependent on phytodetritus, and they consume foraminifera- and sponge derived OM.
{"title":"Trophic ecology of Ophiuroidea and Asteroidea in the Clarion-Clipperton-Fracture Zone (Central Pacific)","authors":"Tanja Stratmann , Erik Simon-Lledó , Marcel T.J. van der Meer , Magdalini Christodoulou , Sven Rossel , Ana Colaço","doi":"10.1016/j.dsr.2025.104598","DOIUrl":"10.1016/j.dsr.2025.104598","url":null,"abstract":"<div><div>Abyssal seascapes represent over 50 % of the Planet's surface, but the life history traits of fauna present in these ecosystems remain poorly understood. Ophiuroidea constitute about one third of the invertebrate megabenthos assemblage between 3800 m and 4800 m water depth in the Clarion-Clipperton Fracture Zone (CCZ); Asteroidea are present in lower densities. We hypothesize that (1) Ophiuroidea, Xenophyophoroidea, and Hexactinellida have a predator-prey relationship, where Ophiuroidea feed on foraminifera- and sponge-derived organic matter (OM). (2) Ophiuroidea have a reduced dependency on fresh phytodetritus. (3) Brisingida (order of Asteroidea), often cling to stalks to have easier access to particulate OM sinking to the seafloor.</div><div>To test these three hypotheses, we combined bulk and compound-specific stable isotope analyses of fauna (Ophiuroidea, Asteroidea) and sediments with analyses of seafloor images from the eastern CCZ.</div><div>All investigated Echinodermata species had a high trophic level. Phospholipid-derived fatty acids (PLFAs) used as biomarkers suggest that <em>Silax daleus</em> consumes sedimentary detritus that is processed by its gut microbiome. <em>Ophiacantha cosmica</em> is likely a top consumer or scavenger, <em>Ophiosphalma glabrum</em> is an opportunistic omnivore ingesting phytodetritus, bacteria, Crustacea, and Foraminifera, while <em>Ophiuroglypha</em> cf. <em>polyacantha</em> (sp. 6) is a more selective omnivore. <em>Freyella benthophila</em> sits mostly on stalks of Hexactinellida and uses this elevated position to catch phytodetritus and zooplankton. <em>Freyastera</em> cf. <em>tuberculata</em>, in comparison, sits mostly on polymetallic nodules from where it preys upon Crustacea moving on the sediment surface. We confirmed that Ophiuroidea are less dependent on phytodetritus, and they consume foraminifera- and sponge derived OM.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"225 ","pages":"Article 104598"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-08-27DOI: 10.1016/j.dsr.2025.104581
Joseph C. Gradone , W. Douglas Wilson , Scott M. Glenn , Travis N. Miles
The Caribbean Through-Flow (CTF) is a critical chokepoint for North and South Atlantic waters that form the North Atlantic western boundary current system and the upper ocean limb of the Atlantic Meridional Overturning Circulation. While the circulation and energetics of the CTF have been well studied, its water mass transformations remain poorly constrained. Using over 7700 Argo float profiles from 2014 to 2024, we document a prominent westward modification in water mass structure across the Caribbean Sea. From the eastern to western Caribbean, we observe systematic increases in ocean heat content, a deepening of isopycnals, and a freshening and deepening of the subsurface salinity maximum. These changes result in a net mid-depth (∼50–500 m) density reduction of 0.40 ± 0.27 kg m-3. We hypothesize that regional variations in mesoscale eddy activity, complex bathymetry, and meridional wind stress curl gradients drive this transformation. The resulting water mass structure has critical implications for regional climate, weather, ecosystems, and sea level rise, as it modifies the density and stratification of source waters entering the Gulf of Mexico and North Atlantic western boundary current system. Our findings highlight the importance of internal Caribbean processes in shaping upper-ocean heat and salt transport in the Atlantic and underscore the need for sustained in situ observations in the region and targeted modeling analyses of the underlying modification processes.
加勒比海通流（CTF）是形成北大西洋西部边界流系统和大西洋经向翻转环流的上层海洋分支的北大西洋和南大西洋水域的关键阻塞点。虽然CTF的循环和能量学已经得到了很好的研究，但它的水质量转化仍然很不受限制。利用2014年至2024年的7700多个Argo浮子剖面，我们记录了加勒比海水团结构的显著西向变化。从加勒比海东部到西部，我们观察到海洋热含量的系统增加，等偏线的加深，以及地下盐度最大值的更新和加深。这些变化导致净中深度（~ 50-500 m）密度降低0.40±0.27 kg m-3。我们假设中尺度涡旋活动的区域变化、复杂的水深测量和经向风应力旋度梯度驱动了这种转变。由此产生的水团结构对区域气候、天气、生态系统和海平面上升具有重要影响，因为它改变了进入墨西哥湾和北大西洋西部边界流系统的源水的密度和分层。我们的研究结果强调了加勒比海内部过程在形成大西洋上层海洋热盐运输中的重要性，并强调了在该地区进行持续的原位观测和对潜在变化过程进行有针对性的建模分析的必要性。
{"title":"Westward modification of Caribbean through-flow water mass structure","authors":"Joseph C. Gradone , W. Douglas Wilson , Scott M. Glenn , Travis N. Miles","doi":"10.1016/j.dsr.2025.104581","DOIUrl":"10.1016/j.dsr.2025.104581","url":null,"abstract":"<div><div>The Caribbean Through-Flow (CTF) is a critical chokepoint for North and South Atlantic waters that form the North Atlantic western boundary current system and the upper ocean limb of the Atlantic Meridional Overturning Circulation. While the circulation and energetics of the CTF have been well studied, its water mass transformations remain poorly constrained. Using over 7700 Argo float profiles from 2014 to 2024, we document a prominent westward modification in water mass structure across the Caribbean Sea. From the eastern to western Caribbean, we observe systematic increases in ocean heat content, a deepening of isopycnals, and a freshening and deepening of the subsurface salinity maximum. These changes result in a net mid-depth (∼50–500 m) density reduction of 0.40 ± 0.27 kg m<sup>-3</sup>. We hypothesize that regional variations in mesoscale eddy activity, complex bathymetry, and meridional wind stress curl gradients drive this transformation. The resulting water mass structure has critical implications for regional climate, weather, ecosystems, and sea level rise, as it modifies the density and stratification of source waters entering the Gulf of Mexico and North Atlantic western boundary current system. Our findings highlight the importance of internal Caribbean processes in shaping upper-ocean heat and salt transport in the Atlantic and underscore the need for sustained in situ observations in the region and targeted modeling analyses of the underlying modification processes.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"225 ","pages":"Article 104581"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144906989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding deep-water variability in the Weddell Sea remains a challenge, given the limited observational coverage and the difficulties ocean models face in representing fine-scale processes, particularly along the Antarctic margin. Recent high-resolution oceanic products offer a valuable opportunity to advance understanding of this region. Nevertheless, it is crucial to critically evaluate their reliability before relying on them for scientific analysis. Here, we assess the representation and variability of Warm Deep Water (WDW), Weddell Sea Deep Water (WSDW), and Weddell Sea Bottom Water (WSBW) in the 1/12° Global Ocean Physics Reanalysis (GLORYS12v1) between 1993 and 2020. GLORYS12v1 reproduces key hydrographic features and vertical stratification below 500 m, despite persistent biases in the upper ocean. WDW shows a spurious freshening trend and a cool bias in Section SR4, diverging from the observed neutral salinity and warming trend. Moreover, WSDW and WSBW exhibit overestimated warming and salinification trends. These discrepancies are primarily linked to (i) a weakening of the Weddell Gyre, which limits inflow and renewal of deep waters; (ii) stronger westerlies enhancing Ekman transport and upwelling; and (iii) changes in sea ice concentration affecting deep convection. A complex maximum covariance analysis reveals strong decadal-scale covariability between the Weddell Gyre barotropic circulation and the thermohaline structure of deep water masses, especially WSDW and WSBW. Although GLORYS12v1 resolves many relevant processes, its overestimation of trends and underrepresentation of coastal dynamics highlight the need for improved vertical coordinate schemes, refined mixing parameterizations, and enhanced observational coverage to better capture the variability of deep waters in polar regions.
{"title":"Variability of the Weddell Sea deep waters in GLORYS12v1 reanalysis","authors":"Marina Noro , Tiago S. Dotto , Marcos Tonelli , Ilana Wainer","doi":"10.1016/j.dsr.2025.104599","DOIUrl":"10.1016/j.dsr.2025.104599","url":null,"abstract":"<div><div>Understanding deep-water variability in the Weddell Sea remains a challenge, given the limited observational coverage and the difficulties ocean models face in representing fine-scale processes, particularly along the Antarctic margin. Recent high-resolution oceanic products offer a valuable opportunity to advance understanding of this region. Nevertheless, it is crucial to critically evaluate their reliability before relying on them for scientific analysis. Here, we assess the representation and variability of Warm Deep Water (WDW), Weddell Sea Deep Water (WSDW), and Weddell Sea Bottom Water (WSBW) in the 1/12° Global Ocean Physics Reanalysis (GLORYS12v1) between 1993 and 2020. GLORYS12v1 reproduces key hydrographic features and vertical stratification below 500 m, despite persistent biases in the upper ocean. WDW shows a spurious freshening trend and a cool bias in Section SR4, diverging from the observed neutral salinity and warming trend. Moreover, WSDW and WSBW exhibit overestimated warming and salinification trends. These discrepancies are primarily linked to (i) a weakening of the Weddell Gyre, which limits inflow and renewal of deep waters; (ii) stronger westerlies enhancing Ekman transport and upwelling; and (iii) changes in sea ice concentration affecting deep convection. A complex maximum covariance analysis reveals strong decadal-scale covariability between the Weddell Gyre barotropic circulation and the thermohaline structure of deep water masses, especially WSDW and WSBW. Although GLORYS12v1 resolves many relevant processes, its overestimation of trends and underrepresentation of coastal dynamics highlight the need for improved vertical coordinate schemes, refined mixing parameterizations, and enhanced observational coverage to better capture the variability of deep waters in polar regions.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"225 ","pages":"Article 104599"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-18DOI: 10.1016/j.dsr.2025.104593
Tengfei Xu , Dingqi Wang , Qinsheng Wei , Shujiang Li , R.D. Susanto , Guanlin Wang , Fei Teng , T. Agustiadi , M. Trenggono , Priyadi Dwi Santoso , Zexun Wei
In this study, we report the phenomenon of sea surface chlorophyll-a (SSC) penetrating front south of Java Island based on satellite observations. The SSC penetrating front occurs frequently (∼17 times per month) during the upwelling season (June to November) and can also be observed (∼4 times per month) during the non-upwelling season (December to May). The offshore distance of the SSC penetrating front can reach up to 500 km and 350 km in the upwelling and non-upwelling seasons, respectively. Eddy-related advection along the eddy edges plays an important role in maintaining the SSC penetrating front by transporting nutrient-rich waters from the Java coast. The interannual variability of the SSC penetrating front is closely associated with the ENSO and IOD events, which tend to induce anomalous upwelling and enhanced mesoscale eddy activity, thereby leading to more frequent occurrences of the SSC penetrating fronts south of Java Island.
{"title":"Satellite-detected sea surface chlorophyll-a penetrating fronts off the south coast of Java Island","authors":"Tengfei Xu , Dingqi Wang , Qinsheng Wei , Shujiang Li , R.D. Susanto , Guanlin Wang , Fei Teng , T. Agustiadi , M. Trenggono , Priyadi Dwi Santoso , Zexun Wei","doi":"10.1016/j.dsr.2025.104593","DOIUrl":"10.1016/j.dsr.2025.104593","url":null,"abstract":"<div><div>In this study, we report the phenomenon of sea surface chlorophyll-a (SSC) penetrating front south of Java Island based on satellite observations. The SSC penetrating front occurs frequently (∼17 times per month) during the upwelling season (June to November) and can also be observed (∼4 times per month) during the non-upwelling season (December to May). The offshore distance of the SSC penetrating front can reach up to 500 km and 350 km in the upwelling and non-upwelling seasons, respectively. Eddy-related advection along the eddy edges plays an important role in maintaining the SSC penetrating front by transporting nutrient-rich waters from the Java coast. The interannual variability of the SSC penetrating front is closely associated with the ENSO and IOD events, which tend to induce anomalous upwelling and enhanced mesoscale eddy activity, thereby leading to more frequent occurrences of the SSC penetrating fronts south of Java Island.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"225 ","pages":"Article 104593"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-04DOI: 10.1016/j.dsr.2025.104590
Penny J. McCowen , Jill R. Bourque , Donald C. Behringer , Nancy G. Prouty , Amanda W.J. Demopoulos
Cold seeps, fueled by hydrocarbon-based chemosynthesis, support unique benthic communities that can vary across small spatial scales influenced by local geochemistry. We examined the community structure and function of macrofauna in cold seeps along the Cascadia margin on the edge of gas hydrate stability—a dynamic environment that may fluctuate as seafloor temperatures change. These communities were assessed in relation to their sediment environment to provide baseline data for these previously uninvestigated seeps and decipher the most significant variables structuring them. Specific environmental drivers investigated include sediment organic carbon, total nitrogen, C:N ratios, stable isotopes (δ13C and δ15N), redox potential, grain size, and porefluid chemistry. Macrofaunal community composition varied across locations separating into twelve distinct clusters. Several co-located cores clustered separately, indicating high heterogeneity in these communities at small spatial scales. Significant drivers of macrofauna communities included clay and sand content, C:N, δ15N values, organic carbon content, and depth. Functional trait composition was influenced by similar drivers, including depth, δ15N values, C:N, and sand content. Our results indicate similar environmental variables structure macrofaunal community composition and function across small- and large-scale gradients, contributing to our understanding of heterogeneity in local and regional factors that shape seep macrofaunal communities. This is the first investigation of macrofauna at these recently discovered seeps and provides baseline data on the hydrate stability zone for future comparisons, advancing our knowledge of broad-scale trends in seep macrofauna ecology.
{"title":"Factors structuring macrofaunal communities of hydrocarbon seeps along the Cascadia margin","authors":"Penny J. McCowen , Jill R. Bourque , Donald C. Behringer , Nancy G. Prouty , Amanda W.J. Demopoulos","doi":"10.1016/j.dsr.2025.104590","DOIUrl":"10.1016/j.dsr.2025.104590","url":null,"abstract":"<div><div>Cold seeps, fueled by hydrocarbon-based chemosynthesis, support unique benthic communities that can vary across small spatial scales influenced by local geochemistry. We examined the community structure and function of macrofauna in cold seeps along the Cascadia margin on the edge of gas hydrate stability—a dynamic environment that may fluctuate as seafloor temperatures change. These communities were assessed in relation to their sediment environment to provide baseline data for these previously uninvestigated seeps and decipher the most significant variables structuring them. Specific environmental drivers investigated include sediment organic carbon, total nitrogen, C:N ratios, stable isotopes (δ<sup>13</sup>C and δ<sup>15</sup>N), redox potential, grain size, and porefluid chemistry. Macrofaunal community composition varied across locations separating into twelve distinct clusters. Several co-located cores clustered separately, indicating high heterogeneity in these communities at small spatial scales. Significant drivers of macrofauna communities included clay and sand content, C:N, δ<sup>15</sup>N values, organic carbon content, and depth. Functional trait composition was influenced by similar drivers, including depth, δ<sup>15</sup>N values, C:N, and sand content. Our results indicate similar environmental variables structure macrofaunal community composition and function across small- and large-scale gradients, contributing to our understanding of heterogeneity in local and regional factors that shape seep macrofaunal communities. This is the first investigation of macrofauna at these recently discovered seeps and provides baseline data on the hydrate stability zone for future comparisons, advancing our knowledge of broad-scale trends in seep macrofauna ecology.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"225 ","pages":"Article 104590"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-10-04DOI: 10.1016/j.dsr.2025.104602
Martina Arcioni , Isabella D'Ambra , Salvatrice Vizzini , Danilo Scannella , Monica Calabrò , Fabio Falsone , Michele Luca Geraci , Marco Oliverio , Sergio Vitale , Germana Garofalo , Gioacchino Bono , Francesco Colloca
The Mediterranean Sea is a biodiversity hotspot where most elasmobranchs are severely threatened, and there is limited knowledge regarding life history traits and trophic ecology. In this context, our study focuses on the trophic ecology of the longnose skate (Dipturus oxyrinchus) in the Strait of Sicily (central Mediterranean), which is designated as an Important Shark and Ray Area. The objectives of the present study were to investigate the main changes in the feeding habits of the species according to ontogeny and bathymetric distribution. We collected 152 specimens at depths between 200 and 700 m from 2016 to 2019. The combination of stomach content and stable isotope analyses allowed to classify the longnose skate as a generalist feeder, with a diet dominated by crustaceans, and smaller contributions of bony fish and cephalopods. The most consumed crustaceans were decapods (including Parapenaeus longirostris, Iridonida speciosa, Chlorotocus crassicornis) and mysids (Lophogaster typicus). Multivariate analyses indicated that predator total length and collection depth had a significant effect on the prey consumption patterns, which was corroborated by General Additive Models (GAM), allowing determination of the most commonly consumed prey. Significant ontogenetic changes were observed, with smaller individuals primarily preying upon benthic organisms and larger individuals adopting a more benthopelagic diet, reflected by a slight increase in trophic position. This study highlights the role of the longnose skate within the bathyal food web of the Strait of Sicily, providing useful information for ecosystem modelling, which will support effective conservation strategies.
{"title":"Trophic ecology of the deep-sea skate Dipturus oxyrinchus (Linnaeus, 1758) in the bathyal food web of the central Mediterranean Sea","authors":"Martina Arcioni , Isabella D'Ambra , Salvatrice Vizzini , Danilo Scannella , Monica Calabrò , Fabio Falsone , Michele Luca Geraci , Marco Oliverio , Sergio Vitale , Germana Garofalo , Gioacchino Bono , Francesco Colloca","doi":"10.1016/j.dsr.2025.104602","DOIUrl":"10.1016/j.dsr.2025.104602","url":null,"abstract":"<div><div>The Mediterranean Sea is a biodiversity hotspot where most elasmobranchs are severely threatened, and there is limited knowledge regarding life history traits and trophic ecology. In this context, our study focuses on the trophic ecology of the longnose skate (<em>Dipturus oxyrinchus</em>) in the Strait of Sicily (central Mediterranean), which is designated as an Important Shark and Ray Area. The objectives of the present study were to investigate the main changes in the feeding habits of the species according to ontogeny and bathymetric distribution. We collected 152 specimens at depths between 200 and 700 m from 2016 to 2019. The combination of stomach content and stable isotope analyses allowed to classify the longnose skate as a generalist feeder, with a diet dominated by crustaceans, and smaller contributions of bony fish and cephalopods. The most consumed crustaceans were decapods (including <em>Parapenaeus longirostris, Iridonida speciosa</em>, <em>Chlorotocus crassicornis</em>) and mysids (<em>Lophogaster typicus</em>). Multivariate analyses indicated that predator total length and collection depth had a significant effect on the prey consumption patterns, which was corroborated by General Additive Models (GAM), allowing determination of the most commonly consumed prey. Significant ontogenetic changes were observed, with smaller individuals primarily preying upon benthic organisms and larger individuals adopting a more benthopelagic diet, reflected by a slight increase in trophic position. This study highlights the role of the longnose skate within the bathyal food web of the Strait of Sicily, providing useful information for ecosystem modelling, which will support effective conservation strategies.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"225 ","pages":"Article 104602"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-24DOI: 10.1016/j.dsr.2025.104596
Kathryn E. Medina, Rosanna J. Milligan, Tracey T. Sutton, Tamara Frank
The Charlie Gibbs Fracture Zone (CGFZ) consists of two nearly parallel fracture transform faults that intersect the Mid-Atlantic Ridge (MAR) axis. This area has high primary productivity and biomass levels due to the topography and water. A predominant hydrographic feature of the MAR is the Sub-Polar Front (SPF) which runs along the southern edge of the CGFZ and is known as a biogeographical boundary for multiple species. As part of The Census of Marine Life project Patterns and Processes of the Ecosystem of the northern Mid-Atlantic (MAR-ECO), the abundance and distribution patterns of the CGFZ crustacean community (primarily Decapoda) surveyed during the 2009 H B. Bigelow voyage were analyzed. Specimens were collected from five discrete depths, ranging between 0 and 3500 m deep, using a Norwegian microzooplankton trawl equipped with a multi-sampler. Analyses indicate that geographic location relative to the CGFZ is correlated to pelagic crustacean distribution, but the surrounding water masses are likely the primary drivers of abundance and diversity variations. The abundance of pelagic crustaceans was higher in the cold waters to the northwest of the CGFZ. A higher diversity was found in the warmer southeastern waters presumably due to stable influx of nutrients and food supply, and dominating mesoscale eddies located in the southeast of the study area. Benthic crustaceans in the northwest had an increased abundance and diversity compared the southeast region. This suggests that at depth, the MAR may act as a biogeographic barrier separating the two geographic regions and reducing connectivity.
{"title":"Crustacean assemblage structure over the Charlie-Gibbs Fracture Zone of the Mid-Atlantic Ridge collected during the 2009 Henry B. Bigelow expedition","authors":"Kathryn E. Medina, Rosanna J. Milligan, Tracey T. Sutton, Tamara Frank","doi":"10.1016/j.dsr.2025.104596","DOIUrl":"10.1016/j.dsr.2025.104596","url":null,"abstract":"<div><div>The Charlie Gibbs Fracture Zone (CGFZ) consists of two nearly parallel fracture transform faults that intersect the Mid-Atlantic Ridge (MAR) axis. This area has high primary productivity and biomass levels due to the topography and water. A predominant hydrographic feature of the MAR is the Sub-Polar Front (SPF) which runs along the southern edge of the CGFZ and is known as a biogeographical boundary for multiple species. As part of The Census of Marine Life project Patterns and Processes of the Ecosystem of the northern Mid-Atlantic (MAR-ECO), the abundance and distribution patterns of the CGFZ crustacean community (primarily Decapoda) surveyed during the 2009 H B. Bigelow voyage were analyzed. Specimens were collected from five discrete depths, ranging between 0 and 3500 m deep, using a Norwegian microzooplankton trawl equipped with a multi-sampler. Analyses indicate that geographic location relative to the CGFZ is correlated to pelagic crustacean distribution, but the surrounding water masses are likely the primary drivers of abundance and diversity variations. The abundance of pelagic crustaceans was higher in the cold waters to the northwest of the CGFZ. A higher diversity was found in the warmer southeastern waters presumably due to stable influx of nutrients and food supply, and dominating mesoscale eddies located in the southeast of the study area. Benthic crustaceans in the northwest had an increased abundance and diversity compared the southeast region. This suggests that at depth, the MAR may act as a biogeographic barrier separating the two geographic regions and reducing connectivity.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"225 ","pages":"Article 104596"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01Epub Date: 2025-09-06DOI: 10.1016/j.dsr.2025.104591
Aline Barbosa Silva , Leandro Nolé Eduardo , Juliano Lauser Coletto , Laura Alma Costa , Rafael André Avila , José Henrique Muelbert
We conducted a biodiversity assessment of deep-pelagic fish species in the Subtropical Southwestern Atlantic Ocean, using three complementary fishing methods across depths from 97 to 2570 m between 1996 and 2022. This analysis includes 926,657 specimens, representing 74 species from 11 orders and 18 families. Using these data, we present relationships with environmental factors and a detailed species inventory illustrating diversity and dominance patterns. Distinct from other Southwestern Atlantic ecoregions, our findings reveal high species dominance coupled with relatively low diversity. Among the collected taxa, Diaphus dumerilii (Myctophidae) and Maurolicus stehmanni (Sternoptychidae) constituted over 90 % of all specimens. Analysis of their distribution in relation to water properties reveals that these species exhibit a greater tolerance to a broad range of temperature and salinity conditions, an adaptive trait that likely drives their ecological dominance in the deep-pelagic ecosystems of the study area. The dominance pattern held consistently across all fishing methods, though we observed notable variation in species diversity and abundance between collection techniques. This study provides an important assessment of the deep-pelagic fish fauna in this region, establishing a valuable baseline for future research targeting this largely unexplored fauna.
{"title":"Biodiversity and distribution of deep-pelagic fishes from the subtropical Southwestern Atlantic","authors":"Aline Barbosa Silva , Leandro Nolé Eduardo , Juliano Lauser Coletto , Laura Alma Costa , Rafael André Avila , José Henrique Muelbert","doi":"10.1016/j.dsr.2025.104591","DOIUrl":"10.1016/j.dsr.2025.104591","url":null,"abstract":"<div><div>We conducted a biodiversity assessment of deep-pelagic fish species in the Subtropical Southwestern Atlantic Ocean, using three complementary fishing methods across depths from 97 to 2570 m between 1996 and 2022. This analysis includes 926,657 specimens, representing 74 species from 11 orders and 18 families. Using these data, we present relationships with environmental factors and a detailed species inventory illustrating diversity and dominance patterns. Distinct from other Southwestern Atlantic ecoregions, our findings reveal high species dominance coupled with relatively low diversity. Among the collected taxa, <em>Diaphus dumerilii</em> (Myctophidae) and <em>Maurolicus stehmanni</em> (Sternoptychidae) constituted over 90 % of all specimens. Analysis of their distribution in relation to water properties reveals that these species exhibit a greater tolerance to a broad range of temperature and salinity conditions, an adaptive trait that likely drives their ecological dominance in the deep-pelagic ecosystems of the study area. The dominance pattern held consistently across all fishing methods, though we observed notable variation in species diversity and abundance between collection techniques. This study provides an important assessment of the deep-pelagic fish fauna in this region, establishing a valuable baseline for future research targeting this largely unexplored fauna.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"225 ","pages":"Article 104591"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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