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Nissen C, Lovenduski NS, Brooks CM, Hoppema M, Timmermann R, Hauck J. Severe 21st-century ocean acidification in Antarctic Marine Protected Areas. Nat Commun 2024; 15:259. [PMID: 38177177 PMCID: PMC10766974 DOI: 10.1038/s41467-023-44438-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 12/13/2023] [Indexed: 01/06/2024] Open
Abstract
Antarctic coastal waters are home to several established or proposed Marine Protected Areas (MPAs) supporting exceptional biodiversity. Despite being threatened by anthropogenic climate change, uncertainties remain surrounding the future ocean acidification (OA) of these waters. Here we present 21st-century projections of OA in Antarctic MPAs under four emission scenarios using a high-resolution ocean-sea ice-biogeochemistry model with realistic ice-shelf geometry. By 2100, we project pH declines of up to 0.36 (total scale) for the top 200 m. Vigorous vertical mixing of anthropogenic carbon produces severe OA throughout the water column in coastal waters of proposed and existing MPAs. Consequently, end-of-century aragonite undersaturation is ubiquitous under the three highest emission scenarios. Given the cumulative threat to marine ecosystems by environmental change and activities such as fishing, our findings call for strong emission-mitigation efforts and further management strategies to reduce pressures on ecosystems, such as the continuation and expansion of Antarctic MPAs.
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Affiliation(s)
- Cara Nissen
- Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, USA.
- Alfred Wegener Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany.
| | - Nicole S Lovenduski
- Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, USA
| | - Cassandra M Brooks
- Department of Environmental Studies and Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, USA
| | - Mario Hoppema
- Alfred Wegener Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
| | - Ralph Timmermann
- Alfred Wegener Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
| | - Judith Hauck
- Alfred Wegener Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
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2
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Rotella JJ. Patterns, sources, and consequences of variation in age-specific vital rates: Insights from a long-term study of Weddell seals. J Anim Ecol 2023; 92:552-567. [PMID: 36495476 DOI: 10.1111/1365-2656.13870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022]
Abstract
Variations in the reproductive and survival abilities of individuals within a population are ubiquitous in nature, key to individual fitness, and affect population dynamics, which leads to strong interest in understanding causes and consequences of vital-rate variation. For long-lived species, long-term studies of large samples of known-age individuals are ideal for evaluating vital-rate variation. A population of Weddell seals in Erebus Bay, Antarctica, has been studied each Austral spring since the 1960s. Since 1982, all newborns have been tagged each year and multiple capture-mark-recapture (CMR) surveys have been conducted annually. Over the past 20 years, a series of analyses have built on results of earlier research by taking advantage of steady improvements in the project's long-term CMR data and available analytical methods. Here, I summarize progress made on four major topics related to variation in age-specific vital rates for females: early-life survival and age at first reproduction, costs of reproduction, demographic buffering, and demographic senescence. Multistate modelling found that age at first reproduction varies widely (4-14 years of age) and identified contrasting influences of maternal age on survival and recruitment rates of offspring. Subsequent analyses of data for females after recruitment revealed costs of reproduction to both survival and future reproduction and provided strong evidence of demographic buffering. Recent results indicated that important levels of among-individual variation exist in vital rates and revealed contrasting patterns for senescence in reproduction and survival. Sources of variation in vital rates include age, reproductive state, year, and individual. The combination of luck and individual quality results in strong variation in individual fitness outcomes: ~80% of females born in the population produce no offspring, and the remaining 20% vary strongly in lifetime reproductive output (range: 1-23 pups). Further research is needed to identify the specific environmental conditions that lead to annual variation in vital rates and to better understand the origins of individual heterogeneity. Work is also needed to better quantify the relative roles of luck, maternal effects, and environmental conditions on variation in vital rates and to learn the importance of such variation to demographic performance of offspring and on overall population dynamics.
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Affiliation(s)
- Jay J Rotella
- Ecology Department, Montana State University, Bozeman, Montana, USA
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3
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LaRue M, Brooks C, Wege M, Salas L, Gardiner N. High‐resolution satellite imagery meets the challenge of monitoring remote marine protected areas in the Antarctic and beyond. Conserv Lett 2022. [DOI: 10.1111/conl.12884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Michelle LaRue
- Gateway Antarctica, School of Earth and Environment University of Canterbury Christchurch New Zealand
- Department of Earth and Environmental Sciences University of Minnesota Minneapolis Minnesota USA
| | - Cassandra Brooks
- Department of Environmental Studies University of Colorado‐Boulder Boulder Colorado USA
| | - Mia Wege
- Gateway Antarctica, School of Earth and Environment University of Canterbury Christchurch New Zealand
- Department of Zoology and Entomology University of Pretoria Pretoria South Africa
| | | | - Natasha Gardiner
- Gateway Antarctica, School of Earth and Environment University of Canterbury Christchurch New Zealand
- Antarctica New Zealand Christchurch New Zealand
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4
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LaRue M, Salas L, Nur N, Ainley D, Stammerjohn S, Pennycook J, Dozier M, Saints J, Stamatiou K, Barrington L, Rotella J. Insights from the first global population estimate of Weddell seals in Antarctica. SCIENCE ADVANCES 2021; 7:eabh3674. [PMID: 34559555 PMCID: PMC8462891 DOI: 10.1126/sciadv.abh3674] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 08/04/2021] [Indexed: 06/01/2023]
Abstract
The Weddell seal is one of the best-studied marine mammals in the world, owing to a multidecadal demographic effort in the southernmost part of its range. Despite their occurrence around the Antarctic coastline, we know little about larger scale patterns in distribution, population size, or structure. We combined high-resolution satellite imagery from 2011, crowd-sourcing, and habitat modeling to report the first global population estimate for the species and environmental factors that influence its distribution. We estimated ~202,000 (95% confidence interval: 85,345 to 523,140) sub-adult and adult female seals, with proximate ocean depth and fast-ice variables as factors explaining spatial prevalence. Distances to penguin colonies were associated with seal presence, but only emperor penguin population size had a strong negative relationship. The small, estimated population size relative to previous estimates and the seals’ nexus with trophic competitors indicates that a community ecology approach is required in efforts to monitor the Southern Ocean ecosystem.
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Affiliation(s)
- Michelle LaRue
- Department of Earth and Environmental Sciences, University of Minnesota, 116 Church St. SE, Minneapolis, MN, 55455 USA
- School of Earth and Environment, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Leo Salas
- Point Blue Conservation Sciences, 3820 Cypress Drive #11, Petaluma CA 94954 USA
| | - Nadav Nur
- Point Blue Conservation Sciences, 3820 Cypress Drive #11, Petaluma CA 94954 USA
| | - David Ainley
- H. T. Harvey and Associates Ecological Consultants, 983 University Avenue, Building D, Los Gatos, CA 95032 USA
| | - Sharon Stammerjohn
- Institute of Arctic and Alpine Research, University of Colorado Boulder, 4001 Discovery Drive, Boulder, CO 80303 USA
| | - Jean Pennycook
- H. T. Harvey and Associates Ecological Consultants, 983 University Avenue, Building D, Los Gatos, CA 95032 USA
| | - Melissa Dozier
- Maxar Technologies, 1300 W 120th Avenue, Westminster, CO, 80234 USA
| | - Jon Saints
- BlueSky Resources, 2250 6th St, Boulder, CO 80302, USA
| | | | - Luke Barrington
- Google, 1600 Amphitheatre Parkway, Mountain View, CA 94043 USA
| | - Jay Rotella
- Department of Ecology, Montana State University, Bozeman, MT 59717, USA
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5
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Adachi T, Takahashi A, Costa DP, Robinson PW, Hückstädt LA, Peterson SH, Holser RR, Beltran RS, Keates TR, Naito Y. Forced into an ecological corner: Round-the-clock deep foraging on small prey by elephant seals. SCIENCE ADVANCES 2021; 7:7/20/eabg3628. [PMID: 33980496 PMCID: PMC8115928 DOI: 10.1126/sciadv.abg3628] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 03/22/2021] [Indexed: 06/01/2023]
Abstract
Small mesopelagic fishes dominate the world's total fish biomass, yet their ecological importance as prey for large marine animals is poorly understood. To reveal the little-known ecosystem dynamics, we identified prey, measured feeding events, and quantified the daily energy balance of 48 deep-diving elephant seals throughout their oceanic migrations by leveraging innovative technologies: animal-borne smart accelerometers and video cameras. Seals only attained positive energy balance after feeding 1000 to 2000 times per day on small fishes, which required continuous deep diving (80 to 100% of each day). Interspecies allometry suggests that female elephant seals have exceptional diving abilities relative to their body size, enabling them to exploit a unique foraging niche on small but abundant mesopelagic fish. This unique foraging niche requires extreme round-the-clock deep diving, limiting the behavioral plasticity of elephant seals to a changing mesopelagic ecosystem.
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Affiliation(s)
- Taiki Adachi
- National Institute of Polar Research, Tachikawa, Tokyo, Japan.
| | | | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Patrick W Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Luis A Hückstädt
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, USA
| | - Sarah H Peterson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Rachel R Holser
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Roxanne S Beltran
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Theresa R Keates
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Yasuhiko Naito
- National Institute of Polar Research, Tachikawa, Tokyo, Japan
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6
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The buoyancy-based biotope axis of the evolutionary radiation of Antarctic cryonotothenioid fishes. Polar Biol 2020. [DOI: 10.1007/s00300-020-02702-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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7
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Brusa JL, Rotella JJ, Garrott RA, Paterson JT, Link WA. Variation of annual apparent survival and detection rates with age, year and individual identity in male Weddell seals (
Leptonychotes weddellii
) from long‐term mark‐recapture data. POPUL ECOL 2019. [DOI: 10.1002/1438-390x.12036] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jamie L. Brusa
- Department of EcologyMontana State University Bozeman Montana
| | - Jay J. Rotella
- Department of EcologyMontana State University Bozeman Montana
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9
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Paterson JT, Rotella JJ, Link WA, Garrott R. Variation in the vital rates of an Antarctic marine predator: the role of individual heterogeneity. Ecology 2018; 99:2385-2396. [PMID: 30277558 DOI: 10.1002/ecy.2481] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 06/15/2018] [Accepted: 07/05/2018] [Indexed: 11/11/2022]
Abstract
Variation in life-history traits such as lifespan and lifetime reproductive output is thought to arise, in part, due to among-individual differences in the underlying probabilities of survival and reproduction. However, the stochastic nature of demographic processes can also generate considerable variation in fitness-related traits among otherwise-identical individuals. An improved understanding of life-history evolution and population dynamics therefore depends on evaluating the relative role of each of these processes. Here, we used a 33-yr data set with reproductive histories for 1,274 female Weddell seals from Erebus Bay, Antarctica, to assess the strength of evidence for among-individual heterogeneity in the probabilities of survival and reproduction, while accounting for multiple other sources of variation in vital rates. Our analysis used recent advances in Bayesian model selection techniques and diagnostics to directly compare model fit and predictive power between models that included individual effects on survival and reproduction to those that did not. We found strong evidence for costs of reproduction to both survival and future reproduction, with breeders having rates of survival and subsequent reproduction that were 3% and 6% lower than rates for non-breeders. We detected age-related changes in the rates of survival and reproduction, but the patterns differed for the two rates. Survival rates steadily declined from 0.92 at age 7 to 0.56 at the maximal age of 31 yr. In contrast, reproductive rates increased from 0.68 at age 7 to 0.79 at age 16 and then steadily declined to 0.37 for the oldest females. Models that included individual effects explained more variation in observed life histories and had better estimated predictive power than those that did not, indicating their importance in understanding sources of variation among individuals in life-history traits. We found that among-individual heterogeneity in survival was small relative to that for reproduction. Our study, which found patterns of variation in vital rates that are consistent with a series of predictions from life-history theory, is the first to provide a thorough assessment of variation in important vital rates for a long-lived, high-latitude marine mammal while taking full advantage of recent developments in model evaluation.
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Affiliation(s)
- J Terrill Paterson
- Ecology Department, Montana State University, Bozeman, Montana, 59717, USA
| | - Jay J Rotella
- Ecology Department, Montana State University, Bozeman, Montana, 59717, USA
| | - William A Link
- U.S. Geological Survey, Patuxent Wildlife Research Center, Laurel, Maryland, 20708, USA
| | - Robert Garrott
- Ecology Department, Montana State University, Bozeman, Montana, 59717, USA
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10
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Pitman RL, Fearnbach H, Durban JW. Abundance and population status of Ross Sea killer whales (Orcinus orca, type C) in McMurdo Sound, Antarctica: evidence for impact by commercial fishing? Polar Biol 2018. [DOI: 10.1007/s00300-017-2239-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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