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Bender AN, Krause DJ, Goebel ME, Hoffman JI, Lewallen EA, Bonin CA. Genetic diversity and demographic history of the leopard seal: A Southern Ocean top predator. PLoS One 2023; 18:e0284640. [PMID: 37566609 PMCID: PMC10420386 DOI: 10.1371/journal.pone.0284640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 06/14/2023] [Indexed: 08/13/2023] Open
Abstract
Leopard seals (Hydrurga leptonyx) are top predators that can exert substantial top-down control of their Antarctic prey species. However, population trends and genetic diversity of leopard seals remain understudied, limiting our understanding of their ecological role. We investigated the genetic diversity, effective population size and demographic history of leopard seals to provide fundamental data that contextualizes their predatory influence on Antarctic ecosystems. Ninety leopard seals were sampled from the northern Antarctic Peninsula during the austral summers of 2008-2019 and a 405bp segment of the mitochondrial control region was sequenced for each individual. We uncovered moderate levels of nucleotide (π = 0.013) and haplotype (Hd = 0.96) diversity, and the effective population size was estimated at around 24,000 individuals (NE = 24,376; 95% CI: 16,876-33,126). Consistent with findings from other ice-breeding pinnipeds, Bayesian skyline analysis also revealed evidence for population expansion during the last glacial maximum, suggesting that historical population growth may have been boosted by an increase in the abundance of sea ice. Although leopard seals can be found in warmer, sub-Antarctic locations, the species' core habitat is centered on the Antarctic, making it inherently vulnerable to the loss of sea ice habitat due to climate change. Therefore, detailed assessments of past and present leopard seal population trends are needed to inform policies for Antarctic ecosystems.
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Affiliation(s)
- Arona N. Bender
- Marine and Environmental Sciences Department, Hampton University, Hampton, VA, United States of America
| | - Douglas J. Krause
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, NOAA Fisheries, La Jolla, CA, United States of America
| | - Michael E. Goebel
- Ecology and Evolutionary Biology Department, University of California, Santa Cruz, Santa Cruz, CA, United States of America
| | - Joseph I. Hoffman
- Department of Animal Behaviour, University of Bielefeld, Bielefeld, Germany
- British Antarctic Survey, Cambridge, United Kingdom
| | - Eric A. Lewallen
- Department of Biological Sciences, Hampton University, Hampton, VA, United States of America
| | - Carolina A. Bonin
- Marine and Environmental Sciences Department, Hampton University, Hampton, VA, United States of America
- Department of Biological Sciences, Hampton University, Hampton, VA, United States of America
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2
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Antarctic krill (Euphausia superba) distributions, aggregation structures, and predator interactions in Bransfield Strait. Polar Biol 2023. [DOI: 10.1007/s00300-023-03113-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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3
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Watters GM, Hinke JT. Conservation in the Scotia Sea in light of expiring regulations and disrupted negotiations. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2022; 36:e13925. [PMID: 35451530 PMCID: PMC9790540 DOI: 10.1111/cobi.13925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 03/17/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Affiliation(s)
- George M. Watters
- Antarctic Ecosystem Research DivisionSouthwest Fisheries Science CenterNational Marine Fisheries Service, National Oceanic and Atmospheric AdministrationLa JollaCaliforniaUSA
| | - Jefferson T. Hinke
- Antarctic Ecosystem Research DivisionSouthwest Fisheries Science CenterNational Marine Fisheries Service, National Oceanic and Atmospheric AdministrationLa JollaCaliforniaUSA
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4
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Johnston NM, Murphy EJ, Atkinson A, Constable AJ, Cotté C, Cox M, Daly KL, Driscoll R, Flores H, Halfter S, Henschke N, Hill SL, Höfer J, Hunt BPV, Kawaguchi S, Lindsay D, Liszka C, Loeb V, Manno C, Meyer B, Pakhomov EA, Pinkerton MH, Reiss CS, Richerson K, Jr. WOS, Steinberg DK, Swadling KM, Tarling GA, Thorpe SE, Veytia D, Ward P, Weldrick CK, Yang G. Status, Change, and Futures of Zooplankton in the Southern Ocean. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.624692] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In the Southern Ocean, several zooplankton taxonomic groups, euphausiids, copepods, salps and pteropods, are notable because of their biomass and abundance and their roles in maintaining food webs and ecosystem structure and function, including the provision of globally important ecosystem services. These groups are consumers of microbes, primary and secondary producers, and are prey for fishes, cephalopods, seabirds, and marine mammals. In providing the link between microbes, primary production, and higher trophic levels these taxa influence energy flows, biological production and biomass, biogeochemical cycles, carbon flux and food web interactions thereby modulating the structure and functioning of ecosystems. Additionally, Antarctic krill (Euphausia superba) and various fish species are harvested by international fisheries. Global and local drivers of change are expected to affect the dynamics of key zooplankton species, which may have potentially profound and wide-ranging implications for Southern Ocean ecosystems and the services they provide. Here we assess the current understanding of the dominant metazoan zooplankton within the Southern Ocean, including Antarctic krill and other key euphausiid, copepod, salp and pteropod species. We provide a systematic overview of observed and potential future responses of these taxa to a changing Southern Ocean and the functional relationships by which drivers may impact them. To support future ecosystem assessments and conservation and management strategies, we also identify priorities for Southern Ocean zooplankton research.
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5
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Warwick‐Evans V, Kelly N, Dalla Rosa L, Friedlaender A, Hinke JT, Kim JH, Kokubun N, Santora JA, Secchi ER, Seyboth E, Trathan PN. Using seabird and whale distribution models to estimate spatial consumption of krill to inform fishery management. Ecosphere 2022. [DOI: 10.1002/ecs2.4083] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
| | - N. Kelly
- Department of Agriculture, Water and the Environment Australian Antarctic Division Kingston Tasmania Australia
| | - L. Dalla Rosa
- Laboratório de Ecologia e Conservação da Megafauna Marinha Instituto de Oceanografia, Universidade Federal de Rio Grande—FURG Rio Grande Brazil
| | - A. Friedlaender
- Institute for Marine Sciences University of California Santa Cruz Santa Cruz California USA
| | - J. T. Hinke
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California USA
| | - J. H. Kim
- Korea Polar Research Institute Incheon South Korea
| | - N. Kokubun
- National Institute of Polar Research Tokyo Japan
| | - J. A. Santora
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service National Oceanic and Atmospheric Administration Santa Cruz California USA
- Department of Applied Mathematics University of California Santa Cruz Santa Cruz California USA
| | - E. R. Secchi
- Laboratório de Ecologia e Conservação da Megafauna Marinha Instituto de Oceanografia, Universidade Federal de Rio Grande—FURG Rio Grande Brazil
| | - E. Seyboth
- Laboratório de Ecologia e Conservação da Megafauna Marinha Instituto de Oceanografia, Universidade Federal de Rio Grande—FURG Rio Grande Brazil
- Centre for Sustainable Oceans, Faculty of Applied Sciences Cape Peninsula University of Cape Town Cape Town South Africa
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6
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Oosthuizen WC, Pistorius PA, Korczak‐Abshire M, Hinke JT, Santos M, Lowther AD. The foraging behavior of nonbreeding Adélie penguins in the western Antarctic Peninsula during the breeding season. Ecosphere 2022. [DOI: 10.1002/ecs2.4090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- W. Chris Oosthuizen
- Marine Apex Predator Research Unit, Institute for Coastal and Marine Research and Department of Zoology Nelson Mandela University Port Elizabeth South Africa
- Centre for Statistics in Ecology, Environment and Conservation, Department of Statistical Sciences University of Cape Town Cape Town South Africa
| | - Pierre A. Pistorius
- Marine Apex Predator Research Unit, Institute for Coastal and Marine Research and Department of Zoology Nelson Mandela University Port Elizabeth South Africa
| | | | - Jefferson T. Hinke
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center National Marine Fisheries Service, National Oceanic and Atmospheric Administration La Jolla California USA
| | - Mercedes Santos
- Departamento Biología de Predadores Tope Instituto Antártico Argentino Buenos Aires Argentina
- Laboratorios Anexos Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata Buenos Aires Argentina
| | - Andrew D. Lowther
- Norwegian Polar Institute, Research Department Fram Centre Tromsø Norway
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7
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McCormack SA, Melbourne-Thomas J, Trebilco R, Griffith G, Hill SL, Hoover C, Johnston NM, Marina TI, Murphy EJ, Pakhomov EA, Pinkerton M, Plagányi É, Saravia LA, Subramaniam RC, Van de Putte AP, Constable AJ. Southern Ocean Food Web Modelling: Progress, Prognoses, and Future Priorities for Research and Policy Makers. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.624763] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Graphical AbstractGraphical summary of multiple aspects of Southern Ocean food web structure and function including alternative energy pathways through pelagic food webs, climate change and fisheries impacts and the importance of microbial networks and benthic systems.
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8
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Free CM, Jensen OP, Hilborn R. Evaluating impacts of forage fish abundance on marine predators. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2021; 35:1540-1551. [PMID: 33899227 DOI: 10.1111/cobi.13709] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 01/22/2021] [Indexed: 06/12/2023]
Abstract
Forage fish-small, low trophic level, pelagic fish such as herrings, sardines, and anchovies-are important prey species in marine ecosystems and also support large commercial fisheries. In many parts of the world, forage fish fisheries are managed using precautionary principles that target catch limits below the maximum sustainable yield. However, there are increasing calls to further limit forage fish catch to safeguard their fish, seabird, and marine mammal predators. The effectiveness of these extra-precautionary regulations, which assume that increasing prey abundance increases predator productivity, are under debate. In this study, we used prey-linked population models to measure the influence of forage fish abundance on the population growth rates of 45 marine predator populations representing 32 fish, seabird, and mammal species from 5 regions around the world. We used simulated data to confirm the ability of the statistical model to accurately detect prey influences under varying levels of influence strength and process variability. Our results indicate that predator productivity was rarely influenced by the abundance of their forage fish prey. Only 6 predator populations (13% of the total) were positively influenced by increasing prey abundance and the model exhibited high power to detect prey influences when they existed. These results suggest that additional limitation of forage fish harvest to levels well below sustainable yields would rarely result in detectable increases in marine predator populations.
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Affiliation(s)
- Christopher M Free
- Bren School of Environmental Science and Management, University of California, Santa Barbara, Santa Barbara, California, USA
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, New Jersey, USA
| | - Olaf P Jensen
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, New Jersey, USA
- University of Wisconsin - Madison, Center for Limnology, 680 N Park St., Madison, WI, 53706, USA
| | - Ray Hilborn
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, USA
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Grant SM, Waller CL, Morley SA, Barnes DKA, Brasier MJ, Double MC, Griffiths HJ, Hughes KA, Jackson JA, Waluda CM, Constable AJ. Local Drivers of Change in Southern Ocean Ecosystems: Human Activities and Policy Implications. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.624518] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Local drivers are human activities or processes that occur in specific locations, and cause physical or ecological change at the local or regional scale. Here, we consider marine and land-derived pollution, non-indigenous species, tourism and other human visits, exploitation of marine resources, recovery of marine mammals, and coastal change as a result of ice loss, in terms of their historic and current extent, and their interactions with the Southern Ocean environment. We summarise projected increases or decreases in the influence of local drivers, and projected changes to their geographic range, concluding that the influence of non-indigenous species, fishing, and the recovery of marine mammals are predicted to increase in the future across the Southern Ocean. Local drivers can be managed regionally, and we identify existing governance frameworks as part of the Antarctic Treaty System and other instruments which may be employed to mitigate or limit their impacts on Southern Ocean ecosystems.
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10
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Korczak-Abshire M, Hinke JT, Milinevsky G, Juáres MA, Watters GM. Coastal regions of the northern Antarctic Peninsula are key for gentoo populations. Biol Lett 2021; 17:20200708. [PMID: 33497589 PMCID: PMC7876601 DOI: 10.1098/rsbl.2020.0708] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Southern Ocean ecosystems are rapidly changing due to climate variability. An apparent beneficiary of such change in the western Antarctic Peninsula (WAP) is the gentoo penguin Pygoscelis papua, which has increased its population size and expanded its range southward in the last 20 years. To better understand how this species has responded to large-scale changes, we tracked individuals during the non-breeding winter period from five colonies across the latitudinal range of breeding sites in the WAP, including from a recently established colony. Results highlight latitudinal gradients in movement; strong associations with shallow, coastal habitats along the entire Antarctic Peninsula; and movements that are independent of, yet constrained by, sea ice. It is clear that coastal habitats essential to gentoo penguins during the breeding season are similarly critical during winter. Larger movements of birds from northern colonies in the WAP further suggest that leap-frog migration may influence colonization events by facilitating nest-area prospecting and use of new haul-out sites. Our results support efforts to develop a marine protected area around the WAP. Winter habitats used by gentoo penguins outline high priority areas for improving the management of the spatio-temporally concentrated krill (Euphausia superba) fishery that operates in this region during winter.
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Affiliation(s)
| | - Jefferson T Hinke
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA 92037, USA
| | - Gennadi Milinevsky
- Department of Atmospheric Physics and Geospace, National Antarctic Scientific Center of Ukraine, Kyiv 01601, Ukraine.,Physics Faculty, Taras Shevchenko National University of Kyiv, Kyiv 01033, Ukraine
| | - Mariana A Juáres
- Departamento Biología de Predadores Tope, Instituto Antártico Argentino, San Martín, Buenos Aires B1650CSP, Argentina.,National Scientific and Technical Research Council (CONICET), Ciudad Autónoma de Buenos Aires, C1425FQB, Argentina
| | - George M Watters
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA 92037, USA
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11
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Lowther AD, Staniland I, Lydersen C, Kovacs KM. Male Antarctic fur seals: neglected food competitors of bioindicator species in the context of an increasing Antarctic krill fishery. Sci Rep 2020; 10:18436. [PMID: 33116190 PMCID: PMC7595138 DOI: 10.1038/s41598-020-75148-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 10/07/2020] [Indexed: 11/25/2022] Open
Abstract
The fishery for Antarctic krill is currently managed using a precautionary, ecosystem-based approach to limiting catch, with performance indices from a long-term monitoring program focused on several krill-dependent predators that are used to track ecosystem health. Concerns over increased fishing in concentrated areas and ongoing efforts to establish a Marine Protected Area along the Peninsula, a key fishing region, is driving the development of an adaptive management system for the fishery. The cumulative effects of fishing effort and interactions among krill-dependent predators and their performance is at present neglected in the CCAMLR Ecosystem Monitoring Program. However, we show considerable overlap between male Antarctic fur seals and the krill fishery in a complex mosaic, suggesting potential for cumulative impacts on other krill dependent predators. A holistic view is required as part of future efforts to manage the krill fishery that incorporates various sources of potential impacts on the performance of bioindicator species, including the fishery and its interactions with various krill dependent predators.
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Affiliation(s)
| | | | - C Lydersen
- Norwegian Polar Institute, Tromsö, Norway
| | - K M Kovacs
- Norwegian Polar Institute, Tromsö, Norway
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12
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Comparing feedback and spatial approaches to advance ecosystem-based fisheries management in a changing Antarctic. PLoS One 2020; 15:e0231954. [PMID: 32898163 PMCID: PMC7478840 DOI: 10.1371/journal.pone.0231954] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 04/04/2020] [Indexed: 11/25/2022] Open
Abstract
To implement ecosystem-based approaches to fisheries management, decision makers need insight on the potential costs and benefits of the policy options available to them. In the Southern Ocean, two such options for addressing trade-offs between krill-dependent predators and the krill fishery include “feedback management” (FBM) strategies and marine protected areas (MPAs); in theory, the first adjusts to change, while the latter is robust to change. We compared two possible FBM options to a proposed MPA in the Antarctic Peninsula and Scotia Sea given a changing climate. One of our feedback options, based on the density of Antarctic krill (Euphasia superba), projected modest increases in the abundances of some populations of krill predators, whereas outcomes from our second FBM option, based on changes in the abundances of penguins, were more mixed, with some areas projecting predator population declines. The MPA resulted in greater increases in some, but not all, predator populations than either feedback strategy. We conclude that these differing outcomes relate to the ways the options separate fishing and predator foraging, either by continually shifting the spatial distribution of fishing away from potentially vulnerable populations (FBM) or by permanently closing areas to fishing (the MPA). For the krill fishery, we show that total catches could be maintained using an FBM approach or slightly increased with the MPA, but the fishery would be forced to adjust fishing locations and sometimes fish in areas of relatively low krill density–both potentially significant costs. Our work demonstrates the potential to shift, rather than avoid, ecological risks and the likely costs of fishing, indicating trade-offs for decision makers to consider.
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13
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Klein ES, Watters GM. What's the catch? Profiling the benefits and costs associated with marine protected areas and displaced fishing in the Scotia Sea. PLoS One 2020; 15:e0237425. [PMID: 32785268 PMCID: PMC7423141 DOI: 10.1371/journal.pone.0237425] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 07/02/2020] [Indexed: 11/28/2022] Open
Abstract
Both costs and benefits must be considered when implementing marine protected areas (MPAs), particularly those associated with fishing effort displaced by potential closures. The Southern Ocean offers a case study in understanding such tradeoffs, where MPAs are actively being discussed to achieve a range of protection and sustainable use objectives. Here, we evaluated the possible impacts of two MPA scenarios on the Antarctic krill (Euphausia superba) fishery and krill-dependent predators in the Scotia Sea, explicitly addressing the displacement of fishing from closed areas. For both scenarios, we employed a minimally realistic, spatially explicit ecosystem model and considered three alternative redistributions of displaced fishing. We projected both MPAs to provide positive outcomes for many krill-dependent predators, especially when closed areas included at least 50–75% of their foraging distributions. Further, differences between the scenarios suggest ways to improve seal and penguin protection in the Scotia Sea. MPA scenarios also projected increases in total fishery yields, but alongside risks of fishing in areas where relatively low krill densities could cause the fishery to suspend operations. The three alternatives for redistributing displaced fishing had little effect on benefits to predators, but did matter for the fishery, with greater differences in overall catch and risk of fishing in areas of low krill density when displaced fishing was redistributed evenly among the open areas. Collectively, results suggest a well-designed MPA in the Scotia Sea may protect krill-dependent predators, even with displaced fishing, and preclude further spatial management of the krill fishery outside the MPA. More broadly, outcomes denote the importance of delineating fishing and predator habitat, spatial scales, and the critical trade-offs inherent in MPA development.
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Affiliation(s)
- Emily S. Klein
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA, United States of America
- The Farallon Institute, Petaluma, CA, United States of America
- * E-mail:
| | - George M. Watters
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA, United States of America
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14
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Watters GM, Hinke JT, Reiss CS. Long-term observations from Antarctica demonstrate that mismatched scales of fisheries management and predator-prey interaction lead to erroneous conclusions about precaution. Sci Rep 2020; 10:2314. [PMID: 32047241 PMCID: PMC7012885 DOI: 10.1038/s41598-020-59223-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 01/22/2020] [Indexed: 11/11/2022] Open
Abstract
Low catch limits for forage species are often considered to be precautionary measures that can help conserve marine predators. Difficulties measuring the impacts of fisheries removals on dependent predators maintain this perspective, but consideration of the spatio-temporal scales over which forage species, their predators, and fisheries interact can aid assessment of whether low catch limits are as precautionary as presumed. Antarctic krill are targeted by the largest fishery in the Southern Ocean and are key forage for numerous predators. Current krill removals are considered precautionary and have not been previously observed to affect krill-dependent predators, like penguins. Using a hierarchical model and 30+ years of monitoring data, we show that expected penguin performance was reduced when local harvest rates of krill were ≥0.1, and this effect was similar in magnitude to that of poor environmental conditions. With continued climate warming and high local harvest rates, future observations of penguin performance are predicted to be below the long-term mean with a probability of 0.77. Catch limits that are considered precautionary for forage species simply because the limit is a small proportion of the species’ standing biomass may not be precautionary for their predators.
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Affiliation(s)
- George M Watters
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, 92037, USA.
| | - Jefferson T Hinke
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, 92037, USA
| | - Christian S Reiss
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, 92037, USA
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15
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Tulloch VJD, Plagányi ÉE, Brown C, Richardson AJ, Matear R. Future recovery of baleen whales is imperiled by climate change. GLOBAL CHANGE BIOLOGY 2019; 25:1263-1281. [PMID: 30807685 PMCID: PMC6850638 DOI: 10.1111/gcb.14573] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 11/28/2018] [Accepted: 12/11/2018] [Indexed: 05/24/2023]
Abstract
Historical harvesting pushed many whale species to the brink of extinction. Although most Southern Hemisphere populations are slowly recovering, the influence of future climate change on their recovery remains unknown. We investigate the impacts of two anthropogenic pressures-historical commercial whaling and future climate change-on populations of baleen whales (blue, fin, humpback, Antarctic minke, southern right) and their prey (krill and copepods) in the Southern Ocean. We use a climate-biological coupled "Model of Intermediate Complexity for Ecosystem Assessments" (MICE) that links krill and whale population dynamics with climate change drivers, including changes in ocean temperature, primary productivity and sea ice. Models predict negative future impacts of climate change on krill and all whale species, although the magnitude of impacts on whales differs among populations. Despite initial recovery from historical whaling, models predict concerning declines under climate change, even local extinctions by 2100, for Pacific populations of blue, fin and southern right whales, and Atlantic/Indian fin and humpback whales. Predicted declines were a consequence of reduced prey (copepods/krill) from warming and increasing interspecific competition between whale species. We model whale population recovery under an alternative scenario whereby whales adapt their migratory patterns to accommodate changing sea ice in the Antarctic and a shifting prey base. Plasticity in range size and migration was predicted to improve recovery for ice-associated blue and minke whales. Our study highlights the need for ongoing protection to help depleted whale populations recover, as well as local management to ensure the krill prey base remains viable, but this may have limited success without immediate action to reduce emissions.
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Affiliation(s)
- Vivitskaia J. D. Tulloch
- ARC Centre of Excellence in Environmental DecisionsUniversity of QueenslandSt Lucia, BrisbaneQLDAustralia
- CSIRO Oceans and Atmosphere, Queensland BioSciences Precinct (QBP)St Lucia, BrisbaneQLDAustralia
| | - Éva E. Plagányi
- CSIRO Oceans and Atmosphere, Queensland BioSciences Precinct (QBP)St Lucia, BrisbaneQLDAustralia
| | | | - Anthony J. Richardson
- CSIRO Oceans and Atmosphere, Queensland BioSciences Precinct (QBP)St Lucia, BrisbaneQLDAustralia
- Centre for Applications in Natural Resource Mathematics, School of Mathematics and PhysicsThe University of QueenslandSt LuciaQLDAustralia
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16
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Landymore C, Durance TD, Singh A, Singh AP, Kitts DD. Comparing different dehydration methods on protein quality of krill (Euphausia Pacifica). Food Res Int 2019; 119:276-282. [PMID: 30884657 DOI: 10.1016/j.foodres.2018.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 11/28/2018] [Accepted: 12/01/2018] [Indexed: 11/19/2022]
Abstract
Krill, (Euphausia pacifica) contains a high protein content (>15.4%) and an estimated biological value higher than many animal protein sources. Thus it is considered to be an important source of high-quality protein. However, commercial processing of krill is limited due to problems such as presence of hydrolytic enzymes (proteases, carboxypeptidases, nucleases, and phospholipases), and its small size. These enzymes are released immediately upon krill harvesting, resulting in autolysis, and rapid spoilage. Herein we compared different dehydration methods of krill on its protein quality. We processed Krill using air-drying (AD), vacuum microwave drying at low temperature (VD) and freeze-drying (FD), and also treated krill with chitinase prior to drying (HZ). AD-processed krill displayed the lowest in-vitro digestibility (P < 0.05) along with low apparent in-vivo protein digestibility compared to VD and FD, respectively. This result corresponded to lower available lysine in AD dried krill (5.6 mg/100 mg protein) compared to VD (8.5 mg Lysine /100 mg protein), FD (8.5 mg/100 mg protein), and HZ (8.9 mg/100 mg protein). Using a two-week metabolic study with rats, we found that apparent urinary nitrogen losses and net protein utilization were low in krill, compared to a casein control. The addition of chitinase to krill prior to drying significantly increased protein quality measures. A high fluoride concentration was also detected in dehydrated krill, irrespective of the drying method. It is expected that the fluoride content of krill is an additional factor that will affect protein utilization.
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Affiliation(s)
- Corrie Landymore
- Food, Nutrition, and Health, Faculty of Land & Food Systems, 2205 East Mall, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Timothy D Durance
- Food, Nutrition, and Health, Faculty of Land & Food Systems, 2205 East Mall, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Anika Singh
- Food, Nutrition, and Health, Faculty of Land & Food Systems, 2205 East Mall, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Anubhav Pratap Singh
- Food, Nutrition, and Health, Faculty of Land & Food Systems, 2205 East Mall, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - David D Kitts
- Food, Nutrition, and Health, Faculty of Land & Food Systems, 2205 East Mall, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
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Warwick-Evans V, Ratcliffe N, Lowther AD, Manco F, Ireland L, Clewlow HL, Trathan PN. Using habitat models for chinstrap penguinsPygoscelis antarcticato advise krill fisheries management during the penguin breeding season. DIVERS DISTRIB 2018. [DOI: 10.1111/ddi.12817] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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Impacts of rising sea temperature on krill increase risks for predators in the Scotia Sea. PLoS One 2018; 13:e0191011. [PMID: 29385153 PMCID: PMC5791976 DOI: 10.1371/journal.pone.0191011] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 12/27/2017] [Indexed: 02/02/2023] Open
Abstract
Climate change is a threat to marine ecosystems and the services they provide, and reducing fishing pressure is one option for mitigating the overall consequences for marine biota. We used a minimally realistic ecosystem model to examine how projected effects of ocean warming on the growth of Antarctic krill, Euphausia superba, might affect populations of krill and dependent predators (whales, penguins, seals, and fish) in the Scotia Sea. We also investigated the potential to mitigate depletion risk for predators by curtailing krill fishing at different points in the 21st century. The projected effects of ocean warming on krill biomass were strongest in the northern Scotia Sea, with a ≥40% decline in the mass of individual krill. Projections also suggest a 25% chance that krill biomass will fall below an established depletion threshold (75% of its unimpacted level), with consequent risks for some predator populations, especially penguins. Average penguin abundance declined by up to 30% of its unimpacted level, with up to a 50% chance of falling below the depletion threshold. Simulated krill fishing at currently permitted harvest rates further increased risks for depletion, and stopping fishing offset the increased risks associated with ocean warming in our model to some extent. These results varied by location and species group. Risk reductions at smaller spatial scales also differed from those at the regional level, which suggests that some predator populations may be more vulnerable than others to future changes in krill biomass. However, impacts on predators did not always map directly to those for krill. Our findings indicate the importance of identifying vulnerable marine populations and targeting protection measures at appropriate spatial scales, and the potential for spatially-structured management to avoid aggravating risks associated with rising ocean temperatures. This may help balance tradeoffs among marine ecosystem services in an uncertain future.
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Tarling GA, Ward P, Thorpe SE. Spatial distributions of Southern Ocean mesozooplankton communities have been resilient to long-term surface warming. GLOBAL CHANGE BIOLOGY 2018; 24:132-142. [PMID: 28850764 DOI: 10.1111/gcb.13834] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 06/23/2017] [Indexed: 06/07/2023]
Abstract
The biogeographic response of oceanic planktonic communities to climatic change has a large influence on the future stability of marine food webs and the functioning of global biogeochemical cycles. Temperature plays a pivotal role in determining the distribution of these communities and ocean warming has the potential to cause major distributional shifts, particularly in polar regions where the thermal envelope is narrow. We considered the impact of long-term ocean warming on the spatial distribution of Southern Ocean mesozooplankton communities through examining plankton abundance in relation to sea surface temperature between two distinct periods, separated by around 60 years. Analyses considered 16 dominant mesozooplankton taxa (in terms of biomass and abundance) in the southwest Atlantic sector of the Southern Ocean, from net samples and in situ temperature records collected during the Discovery Investigations (1926-1938) and contemporary campaigns (1996-2013). Sea surface temperature was found to have increased significantly by 0.74°C between the two eras. The corresponding sea surface temperature at which community abundance peaked was also significantly higher in contemporary times, by 0.98°C. Spatial projections indicated that the geographical location of community peak abundance had remained the same between the two eras despite the poleward advance of sea surface isotherms. If the community had remained within the same thermal envelope as in the 1920s-1930s, community peak abundance would be 500 km further south in the contemporary era. Studies in the northern hemisphere have found that dominant taxa, such as calanoid copepods, have conserved their thermal niches and tracked surface isotherms polewards. The fact that this has not occurred in the Southern Ocean suggests that other selective pressures, particularly food availability and the properties of underlying water masses, place greater constraints on spatial distributions in this region. It further demonstrates that this community is thermally resilient to present levels of sea surface warming.
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Affiliation(s)
- Geraint A Tarling
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Peter Ward
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Sally E Thorpe
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
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20
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Hinke JT, Cossio AM, Goebel ME, Reiss CS, Trivelpiece WZ, Watters GM. Identifying Risk: Concurrent Overlap of the Antarctic Krill Fishery with Krill-Dependent Predators in the Scotia Sea. PLoS One 2017; 12:e0170132. [PMID: 28085943 PMCID: PMC5234819 DOI: 10.1371/journal.pone.0170132] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 12/29/2016] [Indexed: 01/30/2023] Open
Abstract
Mitigating direct and indirect interactions between marine predators and fisheries is a motivating factor for ecosystem-based fisheries management (EBFM), especially where predators and fisheries compete for a shared resource. One difficulty in advancing EBFM is parameterizing clear functional responses of predators to indices of prey availability. Alternative characterizations of fishery-predator interactions may therefore benefit the implementation of EBFM. Telemetry data identify foraging areas used by predators and, therefore, represent critical information to mitigate potential competition between predators and fisheries. We analyzed six years (2009-2014) of telemetry data collected at Cape Shirreff, Livingston Island and Admiralty Bay, King George Island, Antarctica, on three species of Pygoscelid penguins and female Antarctic fur seals. In this region, all four species are primarily dependent on Antarctic krill. The tracking data demonstrate local movements near breeding colonies during the austral summer and dispersal from breeding colonies during the winter. We then assessed overlap between predators and the Antarctic krill fishery on a suite of spatiotemporal scales to examine how different data aggregations affect the extent and location of overlap. Concurrent overlap was observed on all spatiotemporal scales considered throughout the Antarctic Peninsula and South Orkney Islands region, including near tagging locations and in distant areas where recent fishing activity has concentrated. Overlap occurred at depths where mean krill densities were relatively high. Our results demonstrate that direct overlap of krill-dependent predators with the krill fishery on small spatiotemporal scales is relatively common throughout the Antarctic Peninsula region. As the krill fishery continues to develop and efforts to implement ecosystem-based management mature, indices of overlap may provide a useful metric for indicating where the risks of fishing are highest. A precautionary approach to allocating krill catches in space would be to avoid large increases in catch where overlap on small spatiotemporal scales is common.
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Affiliation(s)
- Jefferson T. Hinke
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
- * E-mail:
| | - Anthony M. Cossio
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
| | - Michael E. Goebel
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
| | - Christian S. Reiss
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
| | - Wayne Z. Trivelpiece
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
| | - George M. Watters
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
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Hinke JT, Trivelpiece SG, Trivelpiece WZ. Variable vital rates and the risk of population declines in Adélie penguins from the Antarctic Peninsula region. Ecosphere 2017. [DOI: 10.1002/ecs2.1666] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Jefferson T. Hinke
- Antarctic Ecosystem Research Division Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California 92037 USA
| | - Susan G. Trivelpiece
- Antarctic Ecosystem Research Division Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California 92037 USA
| | - Wayne Z. Trivelpiece
- Antarctic Ecosystem Research Division Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California 92037 USA
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22
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Ecosystem Oceanography of Seabird Hotspots: Environmental Determinants and Relationship with Antarctic Krill Within an Important Fishing Ground. Ecosystems 2016. [DOI: 10.1007/s10021-016-0078-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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23
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Ratcliffe N, Hill SL, Staniland IJ, Brown R, Adlard S, Horswill C, Trathan PN. Do krill fisheries compete with macaroni penguins? Spatial overlap in prey consumption and catches during winter. DIVERS DISTRIB 2015. [DOI: 10.1111/ddi.12366] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
- Norman Ratcliffe
- British Antarctic Survey; High Cross, Madingley Road Cambridge CB3 0ET UK
| | - Simeon L. Hill
- British Antarctic Survey; High Cross, Madingley Road Cambridge CB3 0ET UK
| | - Iain J. Staniland
- British Antarctic Survey; High Cross, Madingley Road Cambridge CB3 0ET UK
| | - Ruth Brown
- British Antarctic Survey; High Cross, Madingley Road Cambridge CB3 0ET UK
| | - Stacey Adlard
- British Antarctic Survey; High Cross, Madingley Road Cambridge CB3 0ET UK
| | - Catharine Horswill
- British Antarctic Survey; High Cross, Madingley Road Cambridge CB3 0ET UK
| | - Philip N. Trathan
- British Antarctic Survey; High Cross, Madingley Road Cambridge CB3 0ET UK
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Xavier JC, Hill SL, Belchier M, Bracegirdle TJ, Murphy EJ, Dias JL. From Ice to Penguins: The Role of Mathematics in Antarctic Research. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/978-3-319-16121-1_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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