Pub Date : 2025-02-01DOI: 10.1016/j.pocean.2024.103382
Cecilie Hansen , Erik Askov Mousing , Carsten Hvingel
The invasion and continued expansion of snow crab in the Barents Sea have provided the area with a new and valuable resource. On the negative side, this invasion may lead to changes in the ecosystem, including structural changes and shifts in energy pathways, as we generally view invaders as a problem. We investigated potential effects of snow crab invasion by applying an end-to-end ecosystem model under different scenarios of fishing and food availability. Overall, the model indicated a low negative impact of snow crab on the ecosystem in the region, also in a potential future with a much higher snow crab biomass. Although snow crab may be found to have local negative effects on specific benthic species, in general it appears that they have found a vacant ecological niche in the Barents Sea ecosystem. In addition, network analysis show that the food web of the Barents Sea becomes slightly more complex when including the snow crab, adding predator–prey interactions. By introducing more parallel foodpaths to the food web, this results in a more resilient ecosystem. Model simulations where the availability of prey to snow crab, and lack of fishing pressure maximizes snow crab abundance result in a somewhat increased impact on the food web. Nevertheless, the effects are still minor and there is no indications that the existing commercial fisheries for other species will be significantly affected. Hence, their role as a passive invader should be considered when structuring management responses.
{"title":"Snow crab (Chionoecetes opilio) in the Barents Sea — A passive or problematic invader?","authors":"Cecilie Hansen , Erik Askov Mousing , Carsten Hvingel","doi":"10.1016/j.pocean.2024.103382","DOIUrl":"10.1016/j.pocean.2024.103382","url":null,"abstract":"<div><div>The invasion and continued expansion of snow crab in the Barents Sea have provided the area with a new and valuable resource. On the negative side, this invasion may lead to changes in the ecosystem, including structural changes and shifts in energy pathways, as we generally view invaders as a problem. We investigated potential effects of snow crab invasion by applying an end-to-end ecosystem model under different scenarios of fishing and food availability. Overall, the model indicated a low negative impact of snow crab on the ecosystem in the region, also in a potential future with a much higher snow crab biomass. Although snow crab may be found to have local negative effects on specific benthic species, in general it appears that they have found a vacant ecological niche in the Barents Sea ecosystem. In addition, network analysis show that the food web of the Barents Sea becomes slightly more complex when including the snow crab, adding predator–prey interactions. By introducing more parallel foodpaths to the food web, this results in a more resilient ecosystem. Model simulations where the availability of prey to snow crab, and lack of fishing pressure maximizes snow crab abundance result in a somewhat increased impact on the food web. Nevertheless, the effects are still minor and there is no indications that the existing commercial fisheries for other species will be significantly affected. Hence, their role as a passive invader should be considered when structuring management responses.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"231 ","pages":"Article 103382"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quantification of abundance and food consumption of seabirds are key to understand characteristics and ecological functions of local marine ecosystem due to their abundance and diversity in foraging areas, habitat, behavior, mobility and prey types. This study aimed to quantify seabird abundance in pelagic areas in the eastern Indian sector of the Southern Ocean (80–150°E) based on an at-sea observational study conducted during the 2018/19 austral summer season. We estimated food consumption by seabirds based on their biomass, estimated field metabolic rates, number of days spent in the areas, and diet composition. Among the five functional seabird groups (penguins, albatrosses/giant petrels, shearwaters, petrels/Charadriiformes, prions/storm-petrels), shearwaters, non-Antarctic resident, were the most dominant taxa both by abundance (15,650,000 birds) and biomass (9,332 tonnes) in the study area during the summer. Most of the prey consumed by all seabirds in the area was presumed to be Antarctic krill (55,504 tonnes) and pelagic fishes (91,695 tonnes), such as myctophids. Although the total food consumption by the seabirds during the summer (209,973 tonnes) was lower than that reported in the Antarctic neritic areas (e.g., 753,000 tonnes in the neighboring Prydz Bay region), the higher proportion of non-resident shearwaters in biomass and estimated food consumption (85%) were the characteristic of the study area. Our results highlight the characteristics of the ecological importance of the study area in which seabirds consume Antarctic krill and pelagic fishes in the upper layer of the water column, and its nutrients are easily transported by the seabirds as their subcutaneous fat or stomach oil to the outside of the areas.
{"title":"Abundance and estimated food consumption of seabirds in the pelagic ecosystem in the eastern Indian sector of the Southern Ocean","authors":"Nobuo Kokubun , Kohei Hamabe , Nodoka Yamada , Hiroko Sasaki , Bungo Nishizawa , Yutaka Watanuki , Hiroto Murase","doi":"10.1016/j.pocean.2024.103385","DOIUrl":"10.1016/j.pocean.2024.103385","url":null,"abstract":"<div><div>Quantification of abundance and food consumption of seabirds are key to understand characteristics and ecological functions of local marine ecosystem due to their abundance and diversity in foraging areas, habitat, behavior, mobility and prey types. This study aimed to quantify seabird abundance in pelagic areas in the eastern Indian sector of the Southern Ocean (80–150°E) based on an at-sea observational study conducted during the 2018/19 austral summer season. We estimated food consumption by seabirds based on their biomass, estimated field metabolic rates, number of days spent in the areas, and diet composition. Among the five functional seabird groups (penguins, albatrosses/giant petrels, shearwaters, petrels/Charadriiformes, prions/storm-petrels), shearwaters, non-Antarctic resident, were the most dominant taxa both by abundance (15,650,000 birds) and biomass (9,332 tonnes) in the study area during the summer. Most of the prey consumed by all seabirds in the area was presumed to be Antarctic krill (55,504 tonnes) and pelagic fishes (91,695 tonnes), such as myctophids. Although the total food consumption by the seabirds during the summer (209,973 tonnes) was lower than that reported in the Antarctic neritic areas (e.g., 753,000 tonnes in the neighboring Prydz Bay region), the higher proportion of non-resident shearwaters in biomass and estimated food consumption (85%) were the characteristic of the study area. Our results highlight the characteristics of the ecological importance of the study area in which seabirds consume Antarctic krill and pelagic fishes in the upper layer of the water column, and its nutrients are easily transported by the seabirds as their subcutaneous fat or stomach oil to the outside of the areas.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"231 ","pages":"Article 103385"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788911","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 : 2025-02-01DOI: 10.1016/j.pocean.2025.103413
Sarah Saldanha , Teresa Militão , Sam L Cox , Irene Llamas-Cano , Herculano Andrade Dinis , Ivandra S.G.C. Gomes , Artur Lopes , Maldini dos Santos , Vania Brito , Marcos Hernández-Montero , Jacob González-Solís
In polar and temperate regions seasonality in environmental conditions is an important driver of animal phenology. In tropical systems, where the environment is relatively homogeneous year-round, the link between phenology and seasonality is weakened, and many species breed asynchronously or even year-round. This leads to the question of how these species adapt to seasonal changes, which remain present albeit to a lesser extent. To assess relationships between foraging plasticity and seasonal changes in oceanographic conditions and resource availability, we investigated the foraging ecology of the red-billed tropicbird (Phaethon aethereus), a poorly studied pantropical species that breeds year-round in Cabo Verde. From 2017 to 2022, we monitored tropicbird nests at three islands (Boavista, Sal and the Cima Islet) and GPS tracked 907 foraging trips from 329 adults to evaluate seasonality in nest occupancy, foraging patterns and efficiency, chick growth, chick and adult body condition, and breeding success, alongside links to seasonal changes in resource availability and environmental conditions. We found seasonal patterns in foraging behaviour, with individuals taking more distant and less sinuous foraging trips, using a larger core foraging area, spending more time foraging during twilight, and consuming more squid in the dry season (December-June), than in the wet season (July-November). Moreover, nest occupancy, chick body condition and breeding success were higher in the dry season. We suggest that the observed seasonal patterns are related to an increase in the availability of squid at the end of the dry season, and a decrease in the nest-site suitability and an increase in weather-related foraging costs in the wet season. Our results provide some of the first in-depth knowledge on the seasonal variation in foraging behaviour of a tropical seabird species, suggesting seasonality in tropical systems may be a stronger driver of the movements of top predators than previously thought.
{"title":"The effect of seasonality on the foraging behaviour and breeding success of a tropical marine top predator","authors":"Sarah Saldanha , Teresa Militão , Sam L Cox , Irene Llamas-Cano , Herculano Andrade Dinis , Ivandra S.G.C. Gomes , Artur Lopes , Maldini dos Santos , Vania Brito , Marcos Hernández-Montero , Jacob González-Solís","doi":"10.1016/j.pocean.2025.103413","DOIUrl":"10.1016/j.pocean.2025.103413","url":null,"abstract":"<div><div>In polar and temperate regions seasonality in environmental conditions is an important driver of animal phenology. In tropical systems, where the environment is relatively homogeneous year-round, the link between phenology and seasonality is weakened, and many species breed asynchronously or even year-round. This leads to the question of how these species adapt to seasonal changes, which remain present albeit to a lesser extent. To assess relationships between foraging plasticity and seasonal changes in oceanographic conditions and resource availability, we investigated the foraging ecology of the red-billed tropicbird (<em>Phaethon aethereus</em>), a poorly studied pantropical species that breeds year-round in Cabo Verde. From 2017 to 2022, we monitored tropicbird nests at three islands (Boavista, Sal and the Cima Islet) and GPS tracked 907 foraging trips from 329 adults to evaluate seasonality in nest occupancy, foraging patterns and efficiency, chick growth, chick and adult body condition, and breeding success, alongside links to seasonal changes in resource availability and environmental conditions. We found seasonal patterns in foraging behaviour, with individuals taking more distant and less sinuous foraging trips, using a larger core foraging area, spending more time foraging during twilight, and consuming more squid in the dry season (December-June), than in the wet season (July-November). Moreover, nest occupancy, chick body condition and breeding success were higher in the dry season. We suggest that the observed seasonal patterns are related to an increase in the availability of squid at the end of the dry season, and a decrease in the nest-site suitability and an increase in weather-related foraging costs in the wet season. Our results provide some of the first in-depth knowledge on the seasonal variation in foraging behaviour of a tropical seabird species, suggesting seasonality in tropical systems may be a stronger driver of the movements of top predators than previously thought.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"231 ","pages":"Article 103413"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141159","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 : 2025-02-01DOI: 10.1016/j.pocean.2024.103387
Ina Nilsen , Cecilie Hansen , Isaac C. Kaplan
As climate change is already altering ocean temperatures, there is an urgent need to understand how environmental changes will affect marine ecosystems. Although great efforts have been made to understand the impacts of ocean warming, there are still uncertainties regarding effects on lower trophic levels and how these may propagate to higher trophic levels. In this study, physics from three different climate projections (SPP1-2.6, SSP2-4.5 and SSP5-8.5) were applied to study the impact of rising temperatures in the Nordic and Barents Seas Atlantis ecosystem model (NoBa Atlantis). We also included variation in phyto- and zooplankton levels to account for the uncertainty regarding how lower trophic levels might respond to climate change. This approach by us is the first study where three different sets of physics have been applied to an end-to-end ecosystem model representing the Nordic and Barents Seas. We therefore treat the projected results with caution, and focus on the underlying mechanisms that drive the changes, to inform future ecosystem studies. The spatial nature of the model (a “shifting chessboard”) allowed us to study how local changes in temperature and prey could affect entire populations. For instance, the thermal niches of mesopelagic fish allowed for an increase in abundance in northern areas, benefiting predators such as blue whiting. On the other hand, thermal limits of capelin together with zooplankton overlap resulted in declines, which subsequently led to reduction in cod growth. This study demonstrates how ecosystem studies could benefit from both modeling and empirical studies that consider not only broad-brush impacts on primary production and trophic transfer, but also spatial considerations of local predator–prey interactions, thermal habitat and spawning-area suitability.
{"title":"A shifting chessboard: Projections of prawn, capelin, mesopelagic fish, zooplankton, and their Nordic and Barents Seas food web under climate change","authors":"Ina Nilsen , Cecilie Hansen , Isaac C. Kaplan","doi":"10.1016/j.pocean.2024.103387","DOIUrl":"10.1016/j.pocean.2024.103387","url":null,"abstract":"<div><div>As climate change is already altering ocean temperatures, there is an urgent need to understand how environmental changes will affect marine ecosystems. Although great efforts have been made to understand the impacts of ocean warming, there are still uncertainties regarding effects on lower trophic levels and how these may propagate to higher trophic levels. In this study, physics from three different climate projections (SPP1-2.6, SSP2-4.5 and SSP5-8.5) were applied to study the impact of rising temperatures in the Nordic and Barents Seas Atlantis ecosystem model (NoBa Atlantis). We also included variation in phyto- and zooplankton levels to account for the uncertainty regarding how lower trophic levels might respond to climate change. This approach by us is the first study where three different sets of physics have been applied to an end-to-end ecosystem model representing the Nordic and Barents Seas. We therefore treat the projected results with caution, and focus on the underlying mechanisms that drive the changes, to inform future ecosystem studies. The spatial nature of the model (a “shifting chessboard”) allowed us to study how local changes in temperature and prey could affect entire populations. For instance, the thermal niches of mesopelagic fish allowed for an increase in abundance in northern areas, benefiting predators such as blue whiting. On the other hand, thermal limits of capelin together with zooplankton overlap resulted in declines, which subsequently led to reduction in cod growth. This study demonstrates how ecosystem studies could benefit from both modeling and empirical studies that consider not only broad-brush impacts on primary production and trophic transfer, but also spatial considerations of local predator–prey interactions, thermal habitat and spawning-area suitability.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"231 ","pages":"Article 103387"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142821050","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 : 2025-02-01DOI: 10.1016/j.pocean.2024.103405
Hyekyung Park , Guebuem Kim , Nahyeon Kwon , Hanbyul Lee , Heejun Han , Joon-Soo Lee , In-Seong Han
We measured seasonal variations in dissolved organic carbon (DOC) and total dissolved amino acids (TDAA)—a major component of bioavailable dissolved organic matter (DOM)—in the continental shelf water of the northwestern Pacific marginal seas, including the Yellow Sea and East China Sea. We show that the TDAA concentrations, especially L-amino acids (L-AA), are predominantly dependent on phytoplankton production, showing elevated values in spring and autumn. Conversely, based on a 228Ra tracer, we found that the concentrations of D-amino acids (D-AA), as well as DOC, are mainly dependent on benthic inputs, with elevated values in autumn and winter. AA-derived indices also show higher DOM bioavailability in spring relative to winter. The TDAA benthic flux (∼3.5 Gmol y-1), which was comparable with phytoplankton production, was about 2-fold higher than its flux from the Changjiang River discharge (∼1.8 Gmol y-1). These findings highlight the crucial role of benthic inputs in controlling the composition and bioavailability of DOM in continental shelf waters.
{"title":"Large seasonal variations in distributions, sources, and fluxes of dissolved amino acids in the continental shelf water","authors":"Hyekyung Park , Guebuem Kim , Nahyeon Kwon , Hanbyul Lee , Heejun Han , Joon-Soo Lee , In-Seong Han","doi":"10.1016/j.pocean.2024.103405","DOIUrl":"10.1016/j.pocean.2024.103405","url":null,"abstract":"<div><div>We measured seasonal variations in dissolved organic carbon (DOC) and total dissolved amino acids (TDAA)—a major component of bioavailable dissolved organic matter (DOM)—in the continental shelf water of the northwestern Pacific marginal seas, including the Yellow Sea and East China Sea. We show that the TDAA concentrations, especially L-amino acids (L-AA), are predominantly dependent on phytoplankton production, showing elevated values in spring and autumn. Conversely, based on a <sup>228</sup>Ra tracer, we found that the concentrations of D-amino acids (D-AA), as well as DOC, are mainly dependent on benthic inputs, with elevated values in autumn and winter. AA-derived indices also show higher DOM bioavailability in spring relative to winter. The TDAA benthic flux (∼3.5 Gmol y<sup>-1</sup>), which was comparable with phytoplankton production, was about 2-fold higher than its flux from the Changjiang River discharge (∼1.8 Gmol y<sup>-1</sup>). These findings highlight the crucial role of benthic inputs in controlling the composition and bioavailability of DOM in continental shelf waters.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"231 ","pages":"Article 103405"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097959","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 : 2025-02-01DOI: 10.1016/j.pocean.2025.103419
Priyanka Banerjee
The Indian Ocean (IO) is characterized by large gradients in atmospheric aerosols and is also an important sink region for atmospheric CO2. However, there are major gaps in our understanding of the linkages between micronutrient dissolved iron (DFe) derived from aerosol over the IO, and the responses of phytoplankton, uptake of CO2 by the upper ocean, and subsequent CO2 sequestration. The present study carries out simulations with an Earth system model to assess the importance of atmospheric sources of DFe in driving the uptake of CO2 over the IO. The results reveal that along with a general increase in upper ocean phytoplankton following atmospheric DFe addition, there are important shifts in phytoplankton functional types. Such shifts impact the dominant biomineral flux and alter the efficiency of export of particulate organic carbon out of the surface mixed layer. The shifts in phytoplankton functional types also largely offset ocean CO2 uptake from positive biological response by reducing surface alkalinity owing to increase in calcium carbonate flux. The dominance of calcium carbonate flux over the Southern Ocean sector of the IO results in net outgassing of CO2 over this region in response to present day atmospheric DFe addition. While the deep ocean carbon sequestration, as indicated by the remineralization length scale of particulate organic carbon, is controlled by ballasting effects of mineral dust over the high-dust northern IO, it is a function of ecosystem structure over the low-dust southern IO. The magnitude and the type of phytoplankton response to atmospheric DFe plays a crucial role in driving the surface-to-deep ocean gradients in dissolved inorganic carbon and alkalinity with the greatest contribution to subsurface dissolved inorganic carbon (alkalinity) response originating from the gas-exchange (carbonate) pump. At interannual timescales, the phytoplankton response to atmospheric sources of DFe depends on availability of nitrate over the northern IO, while phytoplankton response over the southern IO is strongly coupled to the variability of atmospheric iron flux. These results help disentangle the relation between atmospheric deposition of DFe, availability of major nutrients, and phytoplankton functional types and spatial and temporal variation in the net ocean CO2 uptake.
{"title":"The role of atmospheric iron deposition in driving carbon uptake over the Indian Ocean","authors":"Priyanka Banerjee","doi":"10.1016/j.pocean.2025.103419","DOIUrl":"10.1016/j.pocean.2025.103419","url":null,"abstract":"<div><div>The Indian Ocean (IO) is characterized by large gradients in atmospheric aerosols and is also an important sink region for atmospheric CO<sub>2</sub>. However, there are major gaps in our understanding of the linkages between micronutrient dissolved iron (DFe) derived from aerosol over the IO, and the responses of phytoplankton, uptake of CO<sub>2</sub> by the upper ocean, and subsequent CO<sub>2</sub> sequestration. The present study carries out simulations with an Earth system model to assess the importance of atmospheric sources of DFe in driving the uptake of CO<sub>2</sub> over the IO. The results reveal that along with a general increase in upper ocean phytoplankton following atmospheric DFe addition, there are important shifts in phytoplankton functional types. Such shifts impact the dominant biomineral flux and alter the efficiency of export of particulate organic carbon out of the surface mixed layer. The shifts in phytoplankton functional types also largely offset ocean CO<sub>2</sub> uptake from positive biological response by reducing surface alkalinity owing to increase in calcium carbonate flux. The dominance of calcium carbonate flux over the Southern Ocean sector of the IO results in net outgassing of CO<sub>2</sub> over this region in response to present day atmospheric DFe addition. While the deep ocean carbon sequestration, as indicated by the remineralization length scale of particulate organic carbon, is controlled by ballasting effects of mineral dust over the high-dust northern IO, it is a function of ecosystem structure over the low-dust southern IO. The magnitude and the type of phytoplankton response to atmospheric DFe plays a crucial role in driving the surface-to-deep ocean gradients in dissolved inorganic carbon and alkalinity with the greatest contribution to subsurface dissolved inorganic carbon (alkalinity) response originating from the gas-exchange (carbonate) pump. At interannual timescales, the phytoplankton response to atmospheric sources of DFe depends on availability of nitrate over the northern IO, while phytoplankton response over the southern IO is strongly coupled to the variability of atmospheric iron flux. These results help disentangle the relation between atmospheric deposition of DFe, availability of major nutrients, and phytoplankton functional types and spatial and temporal variation in the net ocean CO<sub>2</sub> uptake.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"231 ","pages":"Article 103419"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097964","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 : 2025-02-01DOI: 10.1016/j.pocean.2024.103381
Julia Giebichenstein , Tom Andersen , Øystein Varpe , Geir W. Gabrielsen , Katrine Borgå
Despite numerous studies on mercury in Arctic biota, data from inaccessible, ice-covered regions − especially during the polar night and late winter − remain scarce. This scarcity results in poor understanding of the seasonal dynamics of mercury within the food web. From the Northern Barents Sea, we quantified total mercury and the dietary descriptors δ15N and δ13C as long-term dietary signals (weeks to months) in biota to a) investigate the seasonal pelagic food web structure, b) seasonality in total mercury concentration, c) and its biomagnification in the food web. Mercury and dietary descriptors were analyzed in copepods, macrozooplankton (krill, amphipods, arrow worms, and pteropods) and the fishes, Atlantic cod (Gadus morhua), polar cod (Boreogadus saida) and capelin (Mallotus villosus) during spring, late summer, early, and late winter. Seasonal changes were observed in δ15N values in some macrozooplankton and capelin, and some seasonal variation was observed across the food web with depleted δ13C values in spring and enriched δ13C values in late summer. Mercury concentrations were lower (range: 2.49 ng/g dw in the krill Thyssanossa sp. – 70.55 ng/g dw in the pelagic pteropod Clione limacina) than reported from other parts of the Arctic. We found a positive linear relationship between mercury and relative trophic position represented by δ15N, i.e., biomagnification, during all seasons, except in early winter. As Clione limacina likely had different turnover rates for mercury and stable isotopes resulting in low δ15N, but high mercury concentrations in early winter, compared to the other species in the food web, the pteropod was omitted from the regression. By omitting Clione limacina, biomagnification was similar across all seasons (R2adj = 0.45). Thus, we saw clear mercury biomagnification with consistent and little seasonal variation in this high Arctic marine food web despite large seasonal fluctuations in abiotic and biotic conditions.
{"title":"Little seasonal variation of mercury concentrations and biomagnification in an Arctic pelagic food web","authors":"Julia Giebichenstein , Tom Andersen , Øystein Varpe , Geir W. Gabrielsen , Katrine Borgå","doi":"10.1016/j.pocean.2024.103381","DOIUrl":"10.1016/j.pocean.2024.103381","url":null,"abstract":"<div><div>Despite numerous studies on mercury in Arctic biota, data from inaccessible, ice-covered regions − especially during the polar night and late winter − remain scarce. This scarcity results in poor understanding of the seasonal dynamics of mercury within the food web. From the Northern Barents Sea, we quantified total mercury and the dietary descriptors δ<sup>15</sup>N and δ<sup>13</sup>C as long-term dietary signals (weeks to months) in biota to a) investigate the seasonal pelagic food web structure, b) seasonality in total mercury concentration, c) and its biomagnification in the food web. Mercury and dietary descriptors were analyzed in copepods, macrozooplankton (krill, amphipods, arrow worms, and pteropods) and the fishes, Atlantic cod (<em>Gadus morhua</em>), polar cod (<em>Boreogadus saida</em>) and capelin (<em>Mallotus villosus</em>) during spring, late summer, early, and late winter. Seasonal changes were observed in δ<sup>15</sup>N values in some macrozooplankton and capelin, and some seasonal variation was observed across the food web with depleted δ<sup>13</sup>C values in spring and enriched δ<sup>13</sup>C values in late summer. Mercury concentrations were lower (range: 2.49 ng/g dw in the krill <em>Thyssanossa</em> sp. – 70.55 ng/g dw in the pelagic pteropod <em>Clione limacina</em>) than reported from other parts of the Arctic. We found a positive linear relationship between mercury and relative trophic position represented by δ<sup>15</sup>N, <em>i.e.</em>, biomagnification, during all seasons, except in early winter. As <em>Clione limacina</em> likely had different turnover rates for mercury and stable isotopes resulting in low δ<sup>15</sup>N, but high mercury concentrations in early winter, compared to the other species in the food web, the pteropod was omitted from the regression. By omitting <em>Clione limacina</em>, biomagnification was similar across all seasons (R<sup>2</sup><sub>adj</sub> = 0.45). Thus, we saw clear mercury biomagnification with consistent and little seasonal variation in this high Arctic marine food web despite large seasonal fluctuations in abiotic and biotic conditions.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"231 ","pages":"Article 103381"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.pocean.2025.103417
Vladimir G. Dvoretsky, Alexander G. Dvoretsky
The Barents Sea is a productive region that is experiencing significant climatic fluctuations, making it essential to assess the impact of warming on the local ecosystems by summarizing information on different ecosystem components during various conditions and preceding trends. Our study aimed to reveal spatial patterns in the distribution and structure of zooplankton assemblages along a latitudinal gradient in summer 2013, a warm year, following the colder 2012. Cluster analysis grouped stations into three distinct categories based on the prevailing types of water masses, with higher abundance in colder waters due to the spring phase of plankton succession and higher biomasses in warmer waters. Boreal species were indicative of the southern and central sectors of the sea, while Arctic species and Copepoda nauplii were indicative of high-latitude stations. To elucidate the complex interplay between water mass characteristics, dynamics of nutrient conditions, and zooplankton community structure, both in situ and remote sensing data were used, with the latter covering a two-month period prior to sampling. Water temperature was identified as the primary factor influencing zooplankton assemblages, while nutrient concentrations, along with water currents, also played significant roles in controlling total abundance and biomass. Significant associations between environmental drivers and zooplankton variables were found when using lagged data, highlighting the importance of prior conditions for pelagic communities and shedding light on the underlying mechanisms driving zooplankton distribution and abundance patterns. This study provides valuable insights into the plankton ecology and community dynamics and creates a basis for further elucidating the effects of climate shifts on Arctic marine ecosystems.
{"title":"Summer zooplankton assemblages in the Barents Sea: Spatial variations and effects of environmental conditions as revealed from in situ and satellite data","authors":"Vladimir G. Dvoretsky, Alexander G. Dvoretsky","doi":"10.1016/j.pocean.2025.103417","DOIUrl":"10.1016/j.pocean.2025.103417","url":null,"abstract":"<div><div>The Barents Sea is a productive region that is experiencing significant climatic fluctuations, making it essential to assess the impact of warming on the local ecosystems by summarizing information on different ecosystem components during various conditions and preceding trends. Our study aimed to reveal spatial patterns in the distribution and structure of zooplankton assemblages along a latitudinal gradient in summer 2013, a warm year, following the colder 2012. Cluster analysis grouped stations into three distinct categories based on the prevailing types of water masses, with higher abundance in colder waters due to the spring phase of plankton succession and higher biomasses in warmer waters. Boreal species were indicative of the southern and central sectors of the sea, while Arctic species and Copepoda nauplii were indicative of high-latitude stations. To elucidate the complex interplay between water mass characteristics, dynamics of nutrient conditions, and zooplankton community structure, both in situ and remote sensing data were used, with the latter covering a two-month period prior to sampling. Water temperature was identified as the primary factor influencing zooplankton assemblages, while nutrient concentrations, along with water currents, also played significant roles in controlling total abundance and biomass. Significant associations between environmental drivers and zooplankton variables were found when using lagged data, highlighting the importance of prior conditions for pelagic communities and shedding light on the underlying mechanisms driving zooplankton distribution and abundance patterns. This study provides valuable insights into the plankton ecology and community dynamics and creates a basis for further elucidating the effects of climate shifts on Arctic marine ecosystems.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"231 ","pages":"Article 103417"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142967794","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 : 2025-02-01DOI: 10.1016/j.pocean.2024.103403
Yu Gao , Jinbao Song , Shuang Li , Chengcheng Yu , Peng Hao
Langmuir circulation (LC) and geostrophic effects are crucial physical processes that affect upper-ocean mixing. This study investigates the impact of LC on ocean mixing with a particular focus on geostrophic effects. By combining feedforward neural network (FNN) and Large Eddy Simulation (LES), this study simulated the interaction between varying intensities of LC and different geostrophic effects. The results revealed that the eddy viscosity coefficient in high-latitude areas exceeded that in mid-latitude areas, with this difference being most pronounced in the surface layer and gradually diminishing with depth. Analysis of the vertical momentum flux, upper mixed layer depth, and horizontal velocity shear characteristics demonstrates that geostrophic effects influence high-latitude ocean turbulence and mixing processes. Based on these findings, an improved LC parameterization scheme (KPPLT-FNN) incorporating geostrophic effects was developed, which relies on friction velocity, geostrophic effect, turbulent Langmuir number, and seawater depth. In GOTM, comparative analysis with observational data from COREII and the Ocean Climate Station Papa indicates that KPPLT-FNN demonstrates superior performance in simulating summer ocean temperature, ocean salinity, and winter mixed layer depth. Statistical analysis confirms that the simulation results incorporating geostrophic effects outperform those without such considerations. This study provides valuable insights into improving the accuracy of ocean model simulations.
{"title":"Parameterization of Langmuir circulation under geostrophic effects using the data-driven approach","authors":"Yu Gao , Jinbao Song , Shuang Li , Chengcheng Yu , Peng Hao","doi":"10.1016/j.pocean.2024.103403","DOIUrl":"10.1016/j.pocean.2024.103403","url":null,"abstract":"<div><div>Langmuir circulation (LC) and geostrophic effects are crucial physical processes that affect upper-ocean mixing. This study investigates the impact of LC on ocean mixing with a particular focus on geostrophic effects. By combining feedforward neural network (FNN) and Large Eddy Simulation (LES), this study simulated the interaction between varying intensities of LC and different geostrophic effects. The results revealed that the eddy viscosity coefficient in high-latitude areas exceeded that in mid-latitude areas, with this difference being most pronounced in the surface layer and gradually diminishing with depth. Analysis of the vertical momentum flux, upper mixed layer depth, and horizontal velocity shear characteristics demonstrates that geostrophic effects influence high-latitude ocean turbulence and mixing processes. Based on these findings, an improved LC parameterization scheme (KPPLT-FNN) incorporating geostrophic effects was developed, which relies on friction velocity, geostrophic effect, turbulent Langmuir number, and seawater depth. In GOTM, comparative analysis with observational data from COREII and the Ocean Climate Station Papa indicates that KPPLT-FNN demonstrates superior performance in simulating summer ocean temperature, ocean salinity, and winter mixed layer depth. Statistical analysis confirms that the simulation results incorporating geostrophic effects outperform those without such considerations. This study provides valuable insights into improving the accuracy of ocean model simulations.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"231 ","pages":"Article 103403"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142821055","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 : 2025-01-30DOI: 10.1016/j.pocean.2025.103421
G. Cepeda , É. Becker , C. Derisio , A. Severo , E.M. Acha
Studies on species’ functional traits are increasingly used to explore the links between zooplankton community structure and ecosystem functioning. This study investigates copepod diversity across the main frontal types along the continental shelf and shelf break of eastern South America (32°S-55°S), using taxonomic and functional diversity approaches. We analyzed 53 copepod species grouped by five key traits, comparing adult copepod diversity, functional traits, diversity indices, and functional space between frontal systems and surrounding control regions. Contrary to expectations, no significant differences in functional or taxonomic diversity were observed between frontal systems and control regions. Instead, a distinct latitudinal pattern in functional group distribution emerged, shaped by reproductive mode, myelination, feeding traits, and body size. This pattern revealed a decline in species richness, taxonomic diversity, functional richness, and functional space toward southern regions. The findings suggest spatial filtering of specific trait combinations: larger and medium-sized broadcasters and herbivore-omnivore current feeders dominate colder southern systems, while warmer northern systems support a broader array of functional groups, including small-sized sac-spawners, omnivores-detritivores, carnivores, ambush feeders, and cruise feeders. The transition from heterogeneous northern waters—populated by species from the Malvinas Current, subtropical, and subantarctic shelf waters—to colder, less heterogeneous subantarctic waters in the south likely accounts for the greater functional diversity in northern latitudes. These results underscore the role of environmental heterogeneity, species interactions, and ecosystem functioning in shaping copepod communities along the eastern South American continental shelf.
{"title":"Spring copepod functional diversity associated with the oceanographic fronts of the Southwestern Atlantic Ocean","authors":"G. Cepeda , É. Becker , C. Derisio , A. Severo , E.M. Acha","doi":"10.1016/j.pocean.2025.103421","DOIUrl":"10.1016/j.pocean.2025.103421","url":null,"abstract":"<div><div>Studies on species’ functional traits are increasingly used to explore the links between zooplankton community structure and ecosystem functioning. This study investigates copepod diversity across the main frontal types along the continental shelf and shelf break of eastern South America (32°S-55°S), using taxonomic and functional diversity approaches. We analyzed 53 copepod species grouped by five key traits, comparing adult copepod diversity, functional traits, diversity indices, and functional space between frontal systems and surrounding control regions. Contrary to expectations, no significant differences in functional or taxonomic diversity were observed between frontal systems and control regions. Instead, a distinct latitudinal pattern in functional group distribution emerged, shaped by reproductive mode, myelination, feeding traits, and body size. This pattern revealed a decline in species richness, taxonomic diversity, functional richness, and functional space toward southern regions. The findings suggest spatial filtering of specific trait combinations: larger and medium-sized broadcasters and herbivore-omnivore current feeders dominate colder southern systems, while warmer northern systems support a broader array of functional groups, including small-sized sac-spawners, omnivores-detritivores, carnivores, ambush feeders, and cruise feeders. The transition from heterogeneous northern waters—populated by species from the Malvinas Current, subtropical, and subantarctic shelf waters—to colder, less heterogeneous subantarctic waters in the south likely accounts for the greater functional diversity in northern latitudes. These results underscore the role of environmental heterogeneity, species interactions, and ecosystem functioning in shaping copepod communities along the eastern South American continental shelf.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"232 ","pages":"Article 103421"},"PeriodicalIF":3.8,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143351181","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号