Pub Date : 2025-08-01Epub Date: 2025-05-07DOI: 10.1016/j.dsr.2025.104515
Emanuel Pereira , Daniel Roccatagliata , María José Corriale , Brenda L. Doti
The present study investigates the diversity of the deep-sea Valvifera from the Mar del Plata submarine canyon and adjacent area (MdPSC-AA), Southwest Atlantic. Forty-one benthic samples collected between 250 and 3282 m depth during the “Talud Continental I–III” expeditions were studied. Valviferan isopods were recovered from 34 of the 41 samples collected. A total of 25 valviferan species were identified, which were distributed among four families: Antarcturidae (19 spp.), Austrarcturellidae (4 spp.), Idoteidae (1 sp.), and Pseudidotheidae (1 sp.). Eight new species, eight new geographic records and 11 new bathymetric records are reported. The number of species per haul was negatively associated with depth. Beta diversity showed a moderately high turnover of species across the depth gradient. The biogeographic analysis revealed that most of the species recorded from the MdPSC-AA were also reported from the slope of the Magellan Region (MR-slope). Novel associations between valviferan isopods and other invertebrates are documented.
{"title":"Into the deep: diversity of valviferan isopods (Crustacea: Peracarida) from the Mar del Plata submarine canyon and adjacent area, Argentina","authors":"Emanuel Pereira , Daniel Roccatagliata , María José Corriale , Brenda L. Doti","doi":"10.1016/j.dsr.2025.104515","DOIUrl":"10.1016/j.dsr.2025.104515","url":null,"abstract":"<div><div>The present study investigates the diversity of the deep-sea Valvifera from the Mar del Plata submarine canyon and adjacent area (MdPSC-AA), Southwest Atlantic. Forty-one benthic samples collected between 250 and 3282 m depth during the “Talud Continental I–III” expeditions were studied. Valviferan isopods were recovered from 34 of the 41 samples collected. A total of 25 valviferan species were identified, which were distributed among four families: Antarcturidae (19 spp.), Austrarcturellidae (4 spp.), Idoteidae (1 sp.), and Pseudidotheidae (1 sp.). Eight new species, eight new geographic records and 11 new bathymetric records are reported. The number of species per haul was negatively associated with depth. Beta diversity showed a moderately high turnover of species across the depth gradient. The biogeographic analysis revealed that most of the species recorded from the MdPSC-AA were also reported from the slope of the Magellan Region (MR-slope). Novel associations between valviferan isopods and other invertebrates are documented.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"222 ","pages":"Article 104515"},"PeriodicalIF":2.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144090644","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 : 2025-08-01Epub Date: 2025-05-10DOI: 10.1016/j.dsr.2025.104516
Brendon Yuri Damini , André L. Brum , Rob A. Hall , Tiago S. Dotto , José Luiz L. Azevedo , Karen J. Heywood , Mauricio M. Mata , Carlos A.E. Garcia , Rodrigo Kerr
Bransfield Strait, situated in the northern Antarctic Peninsula, is a critical area for studying the impacts of climate change. This complexity arises from the convergence of distinct water masses: Transitional Zonal Water with Weddell influence (TWW), and Transitional Zonal Water with Bellingshausen influence (TBW). This study aims to give a long–term description of Bransfield Strait circulation during austral summers through high-quality hydrographic data from 2003 to 2019, altimetry data and the global eddy–resolving ocean reanalysis product GLORYS12v1. Findings reveal a cyclonic ocean circulation pattern within Bransfield Strait, characterized by the northeastward Bransfield Current along the South Shetland Islands and extending to Elephant Island, and the southwestward Antarctic Coastal Current entering near 62.40°S and 55.00°W. GLORYS12v1 and altimetry datasets revealed that: part of the Bransfield Current leaves the eastern basin between King George and Clarence Islands and recirculation around the South Shetland Islands, and provides the first robust estimate over an extended period that TBW is transported between King George and Elephant Islands and feeds Bransfield Current. Our results highlight links between the strength of TBW transport and variability in climate modes, quantifying their magnitude and variability due to wind forcing modulation by combined effects of Southern Annular Mode and El Niño–Southern Oscillation indices (jointly called the SEI index). For instance, time-averaged years of SEI negative conditions reveal 0.10 Sv of TBW entering the Bransfield Strait between King George and Elephant Islands. On the other hand, under SEI positive conditions, the TBW transport increases to 0.31 Sv. These observed changes are crucial for advancing our understanding of regional circulation patterns and their underlying mechanisms, as they directly influence the physical and biogeochemical properties of the region.
{"title":"Summer circulation and water masses transport in Bransfield Strait, Antarctica: An evaluation of their response to combined effects of Southern Annular Mode and El Niño–Southern Oscillation","authors":"Brendon Yuri Damini , André L. Brum , Rob A. Hall , Tiago S. Dotto , José Luiz L. Azevedo , Karen J. Heywood , Mauricio M. Mata , Carlos A.E. Garcia , Rodrigo Kerr","doi":"10.1016/j.dsr.2025.104516","DOIUrl":"10.1016/j.dsr.2025.104516","url":null,"abstract":"<div><div>Bransfield Strait, situated in the northern Antarctic Peninsula, is a critical area for studying the impacts of climate change. This complexity arises from the convergence of distinct water masses: Transitional Zonal Water with Weddell influence (TWW), and Transitional Zonal Water with Bellingshausen influence (TBW). This study aims to give a long–term description of Bransfield Strait circulation during austral summers through high-quality hydrographic data from 2003 to 2019, altimetry data and the global eddy–resolving ocean reanalysis product GLORYS12v1. Findings reveal a cyclonic ocean circulation pattern within Bransfield Strait, characterized by the northeastward Bransfield Current along the South Shetland Islands and extending to Elephant Island, and the southwestward Antarctic Coastal Current entering near 62.40°S and 55.00°W. GLORYS12v1 and altimetry datasets revealed that: part of the Bransfield Current leaves the eastern basin between King George and Clarence Islands and recirculation around the South Shetland Islands, and provides the first robust estimate over an extended period that TBW is transported between King George and Elephant Islands and feeds Bransfield Current. Our results highlight links between the strength of TBW transport and variability in climate modes, quantifying their magnitude and variability due to wind forcing modulation by combined effects of Southern Annular Mode and El Niño–Southern Oscillation indices (jointly called the SEI index). For instance, time-averaged years of SEI negative conditions reveal 0.10 Sv of TBW entering the Bransfield Strait between King George and Elephant Islands. On the other hand, under SEI positive conditions, the TBW transport increases to 0.31 Sv. These observed changes are crucial for advancing our understanding of regional circulation patterns and their underlying mechanisms, as they directly influence the physical and biogeochemical properties of the region.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"222 ","pages":"Article 104516"},"PeriodicalIF":2.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071058","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 : 2025-08-01Epub Date: 2025-05-16DOI: 10.1016/j.dsr.2025.104521
Chee Kong Chim , Koh Siang Tan
Tanaidaceans comprise a significant macrofaunal component of the abyssal plains in the Clarion-Clipperton Fracture Zone (CCFZ), Pacific Ocean. A large amount of tanaid material were examined from the eastern end of CCFZ, specifically the OMS (Singapore) and UK-I (United Kingdom) exploration areas and one of the nearest Area of Particular Environmental Interest APEI-6. Some 1800 individuals were collected from 89 stations at 4016–4336 m depth primarily using the box corer, epibenthic sled and multiple corer during three research cruises conducted between 2013 and 2020. Based on morphological characters, a total of 98 species and morphospecies belonging to 12 families were identified from these specimens, of which 85 % are undescribed. Only seven of the 35 described tanaid species previously recorded from CCFZ were rediscovered in this study. The OMS and UK-I areas recorded 85 and 71 species, respectively, and these high species richness as compared to values reported in other exploration areas could be due to greater sampling effort. Despite the close geographical proximity of OMS and UK-I, only 59 % of recorded species were common between the areas. Differences were observed in tanaid density, species richness and species composition between the northern and southern stations in the combined areas of OMS and UK-I. Interestingly, the relatively distant APEI-6 recorded 11 species, all of which were also present in OMS and UK-I. This study did not detect any relationship between tanaid community measures and abiotic factors. Another important outcome of this study is that the addition of the 250 μm mesh to the usual 300 μm mesh increased the total number of individuals retained on the sieves by 25–32 %, but not the total number of species. Even though the 0–2 cm sediment layer contained 1.4–3.0 times and 2.1–8.3 times more individuals than the 2–5 cm and 5–10 layers, respectively, no species was found exclusively at the top layer.
{"title":"Diversity and distribution of Tanaidacea (Crustacea: Peracarida) in the abyssal polymetallic nodule fields of the eastern Clarion-Clipperton Fracture Zone","authors":"Chee Kong Chim , Koh Siang Tan","doi":"10.1016/j.dsr.2025.104521","DOIUrl":"10.1016/j.dsr.2025.104521","url":null,"abstract":"<div><div>Tanaidaceans comprise a significant macrofaunal component of the abyssal plains in the Clarion-Clipperton Fracture Zone (CCFZ), Pacific Ocean. A large amount of tanaid material were examined from the eastern end of CCFZ, specifically the OMS (Singapore) and UK-I (United Kingdom) exploration areas and one of the nearest Area of Particular Environmental Interest APEI-6. Some 1800 individuals were collected from 89 stations at 4016–4336 m depth primarily using the box corer, epibenthic sled and multiple corer during three research cruises conducted between 2013 and 2020. Based on morphological characters, a total of 98 species and morphospecies belonging to 12 families were identified from these specimens, of which 85 % are undescribed. Only seven of the 35 described tanaid species previously recorded from CCFZ were rediscovered in this study. The OMS and UK-I areas recorded 85 and 71 species, respectively, and these high species richness as compared to values reported in other exploration areas could be due to greater sampling effort. Despite the close geographical proximity of OMS and UK-I, only 59 % of recorded species were common between the areas. Differences were observed in tanaid density, species richness and species composition between the northern and southern stations in the combined areas of OMS and UK-I. Interestingly, the relatively distant APEI-6 recorded 11 species, all of which were also present in OMS and UK-I. This study did not detect any relationship between tanaid community measures and abiotic factors. Another important outcome of this study is that the addition of the 250 μm mesh to the usual 300 μm mesh increased the total number of individuals retained on the sieves by 25–32 %, but not the total number of species. Even though the 0–2 cm sediment layer contained 1.4–3.0 times and 2.1–8.3 times more individuals than the 2–5 cm and 5–10 layers, respectively, no species was found exclusively at the top layer.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"222 ","pages":"Article 104521"},"PeriodicalIF":2.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144123530","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 : 2025-08-01Epub Date: 2025-05-20DOI: 10.1016/j.dsr.2025.104531
Emily Lemagie , Ed Farley , Joseph A. Langan , Phyllis J. Stabeno
It is evident that warming North Pacific Ocean (NPO) temperatures are impacting salmon fitness and survival. Record-low western Alaska chum salmon run sizes were recorded in the Yukon River during 2020 and 2021. Based on recent analyses of Pacific salmon species-specific ocean temperature preferences, chum salmon have the widest thermal preference range; we focus on chum because they may have the greatest resilience to temperature variability and if their range is impacted, it is likely other species will respond to observed warming as well. Thermal suitability was mapped along the seasonal migration based on swimming rates to examine potential interannual range or distribution shifts. Two individual-based models of salmon migration driven by surface temperatures and geostrophic currents were run to test the impact of ocean physics on migration and distribution. We found that in the last decade ocean temperatures have similar magnitude and variability as projected through 2050. Since around 2013, the high suitability migration corridor has shifted northwards into the Bering Sea, but the seasonal migration may not be driven primarily by temperature or ocean currents. Warmer ocean temperatures, marine heatwaves, and loss of seasonal sea ice are likely to have the greatest impacts on western Alaska chum salmon where thermal suitability is lowest–in the Bering Sea in winter, and in the eastern Gulf of Alaska in summer. The impacts at the margins of their habitat range may lead to poor condition, a northward domain shift, and more fish entering the Arctic Ocean.
{"title":"Mapping suitable thermal migration corridors for western Alaska chum salmon in the North Pacific","authors":"Emily Lemagie , Ed Farley , Joseph A. Langan , Phyllis J. Stabeno","doi":"10.1016/j.dsr.2025.104531","DOIUrl":"10.1016/j.dsr.2025.104531","url":null,"abstract":"<div><div>It is evident that warming North Pacific Ocean (NPO) temperatures are impacting salmon fitness and survival. Record-low western Alaska chum salmon run sizes were recorded in the Yukon River during 2020 and 2021. Based on recent analyses of Pacific salmon species-specific ocean temperature preferences, chum salmon have the widest thermal preference range; we focus on chum because they may have the greatest resilience to temperature variability and if their range is impacted, it is likely other species will respond to observed warming as well. Thermal suitability was mapped along the seasonal migration based on swimming rates to examine potential interannual range or distribution shifts. Two individual-based models of salmon migration driven by surface temperatures and geostrophic currents were run to test the impact of ocean physics on migration and distribution. We found that in the last decade ocean temperatures have similar magnitude and variability as projected through 2050. Since around 2013, the high suitability migration corridor has shifted northwards into the Bering Sea, but the seasonal migration may not be driven primarily by temperature or ocean currents. Warmer ocean temperatures, marine heatwaves, and loss of seasonal sea ice are likely to have the greatest impacts on western Alaska chum salmon where thermal suitability is lowest–in the Bering Sea in winter, and in the eastern Gulf of Alaska in summer. The impacts at the margins of their habitat range may lead to poor condition, a northward domain shift, and more fish entering the Arctic Ocean.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"222 ","pages":"Article 104531"},"PeriodicalIF":2.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144123529","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 : 2025-08-01Epub Date: 2025-05-21DOI: 10.1016/j.dsr.2025.104532
Yanan Zhu , Yuanlong Li , Yilong Lyu , Fan Wang
Pacific Ocean water masses can reach the Atlantic through the Indonesian Throughflow (ITF) and Agulhas Current (AC) leakage, constituting an essential route of the global ocean conveyor belt. However, whether the oceanic variability induced by El Niño-Southern Oscillation (ENSO) can efficiently penetrate through this route remains largely uncertain. In this study, we utilize experiments of a high-resolution (0.1° in horizontal resolution) ocean model to revisit pathways of Pacific-origin oceanic signals and their impacts on the Southern Indian Ocean (SIO) circulation. The experiments are performed for the 2014–2022 period to cover the 2015–2016 super El Niño and the 2020–2022 consecutive La Niña. Our results reveal a main pathway of Pacific-origin baroclinic Rossby waves stretching from the Maritime Continent to Madagascar, with ENSO signatures weakening rapidly as proceeding westward. The Pacific-origin oceanic signals explain ∼95 % of the strength variability in the ITF outflow at 116°E, ∼66 % of that in the South Equatorial Current (SEC) and ∼17 % of that in the Northeast Madagascar Current (NEMC) during 2014–2022. Through this “oceanic channel” mechanism, the 2015–2016 El Niño led to a strengthened NEMC in 2016 and a weakened Southeast Madagascar Current (SEMC) in 2017. By contrast, this oceanic channel effect is generally negligible for the AC system which is dominated by ocean internal variability. These results constrain the extent of ENSO's modulation effect on the SIO circulation and imply that effective ocean-channel communication between the Pacific and the Atlantic has to occur on decadal or longer timescales.
{"title":"Pathways and impacts of ENSO-induced oceanic variability in the southern Indian Ocean investigated with high-resolution model simulations","authors":"Yanan Zhu , Yuanlong Li , Yilong Lyu , Fan Wang","doi":"10.1016/j.dsr.2025.104532","DOIUrl":"10.1016/j.dsr.2025.104532","url":null,"abstract":"<div><div>Pacific Ocean water masses can reach the Atlantic through the Indonesian Throughflow (ITF) and Agulhas Current (AC) leakage, constituting an essential route of the global ocean conveyor belt. However, whether the oceanic variability induced by El Niño-Southern Oscillation (ENSO) can efficiently penetrate through this route remains largely uncertain. In this study, we utilize experiments of a high-resolution (0.1° in horizontal resolution) ocean model to revisit pathways of Pacific-origin oceanic signals and their impacts on the Southern Indian Ocean (SIO) circulation. The experiments are performed for the 2014–2022 period to cover the 2015–2016 super El Niño and the 2020–2022 consecutive La Niña. Our results reveal a main pathway of Pacific-origin baroclinic Rossby waves stretching from the Maritime Continent to Madagascar, with ENSO signatures weakening rapidly as proceeding westward. The Pacific-origin oceanic signals explain ∼95 % of the strength variability in the ITF outflow at 116°E, ∼66 % of that in the South Equatorial Current (SEC) and ∼17 % of that in the Northeast Madagascar Current (NEMC) during 2014–2022. Through this “oceanic channel” mechanism, the 2015–2016 El Niño led to a strengthened NEMC in 2016 and a weakened Southeast Madagascar Current (SEMC) in 2017. By contrast, this oceanic channel effect is generally negligible for the AC system which is dominated by ocean internal variability. These results constrain the extent of ENSO's modulation effect on the SIO circulation and imply that effective ocean-channel communication between the Pacific and the Atlantic has to occur on decadal or longer timescales.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"222 ","pages":"Article 104532"},"PeriodicalIF":2.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144123528","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 : 2025-08-01Epub Date: 2025-05-13DOI: 10.1016/j.dsr.2025.104518
Victoria Rodríguez Zanchin , Brenda Temperoni , Eduardo M. Acha , Claudio C. Buratti , Daniela Alemany
Lanternfishes (family Myctophidae) are among the most diverse and abundant fishes that inhabit the world's oceans. They constitute a major part of the biomass in oceanic areas, and they play an important role in life-sustaining processes of marine ecosystems, including carbon cycling. However, in the Southwestern Atlantic Ocean (SWAO), many ecological aspects of the lanternfishes remain understudied. The aim of this study was to investigate the distribution, diversity, assemblage structure and relative abundance of lanternfishes in relation to oceanographic features, between 34° S and 55° S, from the Argentine continental shelf up to 43° W. A database of 2186 fishing trawls conducted during 26 research cruises from 1978 to 2023 was analyzed. Thirty-four lanternfish species were identified, only found in 244 trawls, mostly distributed from the 100 m isobath towards the oceanic domain. This study revealed clear differences in species richness and abundance of lanternfishes between the different areas of the SWAO: 1 or 2 species were found at the shelf break, where high abundances were recorded, while at the northernmost oceanic realm, species richness was higher but with low abundance records. Three main assemblages were defined based on myctophid species composition, whose structure and distribution were strongly influenced by the properties of water masses and the averaged position of the oceanic fronts.
{"title":"Lanternfish (Myctophidae) distribution and diversity patterns in the Southwestern Atlantic Ocean","authors":"Victoria Rodríguez Zanchin , Brenda Temperoni , Eduardo M. Acha , Claudio C. Buratti , Daniela Alemany","doi":"10.1016/j.dsr.2025.104518","DOIUrl":"10.1016/j.dsr.2025.104518","url":null,"abstract":"<div><div>Lanternfishes (family Myctophidae) are among the most diverse and abundant fishes that inhabit the world's oceans. They constitute a major part of the biomass in oceanic areas, and they play an important role in life-sustaining processes of marine ecosystems, including carbon cycling. However, in the Southwestern Atlantic Ocean (SWAO), many ecological aspects of the lanternfishes remain understudied. The aim of this study was to investigate the distribution, diversity, assemblage structure and relative abundance of lanternfishes in relation to oceanographic features, between 34° S and 55° S, from the Argentine continental shelf up to 43° W. A database of 2186 fishing trawls conducted during 26 research cruises from 1978 to 2023 was analyzed. Thirty-four lanternfish species were identified, only found in 244 trawls, mostly distributed from the 100 m isobath towards the oceanic domain. This study revealed clear differences in species richness and abundance of lanternfishes between the different areas of the SWAO: 1 or 2 species were found at the shelf break, where high abundances were recorded, while at the northernmost oceanic realm, species richness was higher but with low abundance records. Three main assemblages were defined based on myctophid species composition, whose structure and distribution were strongly influenced by the properties of water masses and the averaged position of the oceanic fronts.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"222 ","pages":"Article 104518"},"PeriodicalIF":2.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144090643","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 : 2025-08-01Epub Date: 2025-05-22DOI: 10.1016/j.dsr.2025.104530
Alessia C. Ciraolo , Paul V.R. Snelgrove , Marta M. Cecchetto , Andrew K. Sweetman
Global warming has expanded oxygen minimum zones (OMZs), or oceanic “dead zones”. Despite their ecological significance, the diversity, and functional roles of benthic organisms in nutrient cycling and carbon (C) uptake in OMZ remain understudied. In this study, we focused on the Northeast Pacific continental slope OMZ (600–1200 m depth) off Vancouver Island, Canada, along an oxygen and depth transect (∼77, 40, and 10 μmol ‧ l−1 at 200-, 475-, 850-m depth, respectively). Using a multicorer we collected sediment cores and performed shipboard incubations to examine organic matter remineralization and nutrient flux rates. In parallel, we performed pulse-chase tracer incubations with isotopically labeled algae (Phaeodactylum sp.) at the 475- and 850-m sites, to assess macrofaunal C uptake and benthic nutrient flux responses to fresh phytodetritus. Our results revealed no clear influence of decreasing oxygen on macrofaunal abundances, nutrient regeneration, or on the role of infauna in organic matter remineralization. Nontheless, organic matter quantity and quality strongly influenced macrofaunal community structure. Despite differences in community composition among sites, we also observed no clear relationship between macrofaunal community composition and nutrient fluxes, with phytoplankton-based food as a key food source for oxygen-deficient-adapted infauna. The highest C uptake rate and highest net nutrient influxes at the 475 m site contrasted lower rates at 850 m site, where only one flabelligerid and one cirratulid polychaete species ingested the organic matter, followed by amphipods, cumaceans, unidentified crustaceans, and bivalves, all primarily in the upper 2 cm of sediment. Our findings highlight the complex interplay of oxygen, depth, and organic matter, suggesting that organic matter quality and quantity may obscure oxygen effects on benthic biodiversity and ecological processes.
{"title":"The roles of benthic diversity and environmental factors in nutrient and macrofaunal dynamics within the oxygen minimum zone of the British Columbia continental slope","authors":"Alessia C. Ciraolo , Paul V.R. Snelgrove , Marta M. Cecchetto , Andrew K. Sweetman","doi":"10.1016/j.dsr.2025.104530","DOIUrl":"10.1016/j.dsr.2025.104530","url":null,"abstract":"<div><div>Global warming has expanded oxygen minimum zones (OMZs), or oceanic “dead zones”. Despite their ecological significance, the diversity, and functional roles of benthic organisms in nutrient cycling and carbon (C) uptake in OMZ remain understudied. In this study, we focused on the Northeast Pacific continental slope OMZ (600–1200 m depth) off Vancouver Island, Canada, along an oxygen and depth transect (∼77, 40, and 10 μmol ‧ l<sup>−1</sup> at 200-, 475-, 850-m depth, respectively). Using a multicorer we collected sediment cores and performed shipboard incubations to examine organic matter remineralization and nutrient flux rates. In parallel, we performed pulse-chase tracer incubations with isotopically labeled algae (<em>Phaeodactylum</em> sp.) at the 475- and 850-m sites, to assess macrofaunal C uptake and benthic nutrient flux responses to fresh phytodetritus. Our results revealed no clear influence of decreasing oxygen on macrofaunal abundances, nutrient regeneration, or on the role of infauna in organic matter remineralization. Nontheless, organic matter quantity and quality strongly influenced macrofaunal community structure. Despite differences in community composition among sites, we also observed no clear relationship between macrofaunal community composition and nutrient fluxes, with phytoplankton-based food as a key food source for oxygen-deficient-adapted infauna. The highest C uptake rate and highest net nutrient influxes at the 475 m site contrasted lower rates at 850 m site, where only one flabelligerid and one cirratulid polychaete species ingested the organic matter, followed by amphipods, cumaceans, unidentified crustaceans, and bivalves, all primarily in the upper 2 cm of sediment. Our findings highlight the complex interplay of oxygen, depth, and organic matter, suggesting that organic matter quality and quantity may obscure oxygen effects on benthic biodiversity and ecological processes.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"222 ","pages":"Article 104530"},"PeriodicalIF":2.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144146693","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 : 2025-08-01Epub Date: 2025-05-15DOI: 10.1016/j.dsr.2025.104520
B. Shillito , L. Amand , M. Zbinden , D. Barthelemy , J. Tourolle , L. Menot
A set of four identical pressurised mesocosms is presented, aiming at long-term incubations of deep-water corals, as deep as 3000 m. Care was also taken to enable practical boarding of these instruments on oceanographic ships. Four-month incubations of two scleractinian species (D. pertusum and M. oculata) originating from 800 m depth were achieved at the laboratory (including 3 months at 8 MPa pressure). Two of the aquaria were also operated during a 2-week cruise in the Bay of Biscay, focusing on the same species. Specific requirements for long-term studies are exposed and discussed, emphasizing resistance to corrosion and the possibility to feed fauna without decompression. The first-time long-term incubation of deep-water corals at in situ pressure opens perspectives for future studies, including investigations on deeper corals not yet accessible to laboratory experiments. The use of pressurised mesocosms may be of particular importance, considering the predicted consequences of ocean warming and acidification on the bathymetric distribution of reef-forming deep-water scleractinians.
{"title":"Pressurised aquaria for the study of deep-water corals","authors":"B. Shillito , L. Amand , M. Zbinden , D. Barthelemy , J. Tourolle , L. Menot","doi":"10.1016/j.dsr.2025.104520","DOIUrl":"10.1016/j.dsr.2025.104520","url":null,"abstract":"<div><div>A set of four identical pressurised mesocosms is presented, aiming at long-term incubations of deep-water corals, as deep as 3000 m. Care was also taken to enable practical boarding of these instruments on oceanographic ships. Four-month incubations of two scleractinian species (<em>D. pertusum</em> and <em>M. oculata</em>) originating from 800 m depth were achieved at the laboratory (including 3 months at 8 MPa pressure). Two of the aquaria were also operated during a 2-week cruise in the Bay of Biscay, focusing on the same species. Specific requirements for long-term studies are exposed and discussed, emphasizing resistance to corrosion and the possibility to feed fauna without decompression. The first-time long-term incubation of deep-water corals at <em>in situ</em> pressure opens perspectives for future studies, including investigations on deeper corals not yet accessible to laboratory experiments. The use of pressurised mesocosms may be of particular importance, considering the predicted consequences of ocean warming and acidification on the bathymetric distribution of reef-forming deep-water scleractinians.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"222 ","pages":"Article 104520"},"PeriodicalIF":2.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144146652","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}
{"title":"Corrigendum to “Pteropod assemblages in the oceanic waters of the southern Gulf of Mexico (June 2015)” [Deep-Sea Res. Part I 216 (2025) 1–17 104431]","authors":"H.S. López-Arellanes , J.A. Cruz-Barraza , E.D. Ruvalcaba-Aroche , C.A. Silva-Segundo","doi":"10.1016/j.dsr.2025.104504","DOIUrl":"10.1016/j.dsr.2025.104504","url":null,"abstract":"","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"221 ","pages":"Article 104504"},"PeriodicalIF":2.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144098848","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 : 2025-07-01Epub Date: 2025-05-02DOI: 10.1016/j.dsr.2025.104513
Jona R. Silberberg , Dieter Piepenburg , Christiane Hasemann
Knowledge on meiofauna in the Arctic Ocean is lacking despite their importance for ecosystem functioning. The Synoptic Arctic Survey aimed to fill such knowledge gaps and thus included meiofaunal sampling. A bathymetric transect (from shelf to central basins) was sampled in the western Arctic Ocean during the HLY2202 expedition. Four sampled transect stations were investigated to answer three key questions: (1) How does the meiofaunal community change along the transect? (2) Which sedimentary parameters drive the meiofaunal community compositions? (3) Has the meiofaunal community at the North Pole changed since 1996, and if so, how? The uppermost 3 cm of sediment were analyzed for metazoan meiofaunal composition (including meiofaunal abundance and nematode biomass) in relation to food proxies (i.e. bacterial abundance and biomass, organic carbon, phospholipids, chlorophyll a, phaeophytin) and sediment porosity. Meiofaunal density and taxa count decreased with increasing water and sediment depth, as did nematode body sizes. This supported the concept of deep-sea miniaturization. Thicker nematodes dominated near-surface sediments, while slimmer individuals dominated deeper layers, a pattern related to sediment porosity. Sediment pigments (i.e. chlorophyll) and bacteria were confirmed as important food sources, and sediment porosity was corroborated as an important driver of meiofaunal communities. Virtually no differences were found in abundance of higher meiofauna taxa at the North Pole between 1996 and 2022, potentially due to relative stability provided by the still permanent ice-cover. Examining the meiofaunal composition at genus level will allow analysis of potential changes in diversity and ecosystem functions in relation to environmental changes.
{"title":"Creepy-Crawlies of the Arctic deep sea: Metazoan meiobenthic communities across latitudinal and bathymetric gradients in the western Arctic Ocean","authors":"Jona R. Silberberg , Dieter Piepenburg , Christiane Hasemann","doi":"10.1016/j.dsr.2025.104513","DOIUrl":"10.1016/j.dsr.2025.104513","url":null,"abstract":"<div><div>Knowledge on meiofauna in the Arctic Ocean is lacking despite their importance for ecosystem functioning. The Synoptic Arctic Survey aimed to fill such knowledge gaps and thus included meiofaunal sampling. A bathymetric transect (from shelf to central basins) was sampled in the western Arctic Ocean during the HLY2202 expedition. Four sampled transect stations were investigated to answer three key questions: (1) How does the meiofaunal community change along the transect? (2) Which sedimentary parameters drive the meiofaunal community compositions? (3) Has the meiofaunal community at the North Pole changed since 1996, and if so, how? The uppermost 3 cm of sediment were analyzed for metazoan meiofaunal composition (including meiofaunal abundance and nematode biomass) in relation to food proxies (i.e. bacterial abundance and biomass, organic carbon, phospholipids, chlorophyll <em>a</em>, phaeophytin) and sediment porosity. Meiofaunal density and taxa count decreased with increasing water and sediment depth, as did nematode body sizes. This supported the concept of deep-sea miniaturization. Thicker nematodes dominated near-surface sediments, while slimmer individuals dominated deeper layers, a pattern related to sediment porosity. Sediment pigments (i.e. chlorophyll) and bacteria were confirmed as important food sources, and sediment porosity was corroborated as an important driver of meiofaunal communities. Virtually no differences were found in abundance of higher meiofauna taxa at the North Pole between 1996 and 2022, potentially due to relative stability provided by the still permanent ice-cover. Examining the meiofaunal composition at genus level will allow analysis of potential changes in diversity and ecosystem functions in relation to environmental changes.</div></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":"221 ","pages":"Article 104513"},"PeriodicalIF":2.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936989","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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