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LaRue M, Iles D, Labrousse S, Fretwell P, Ortega D, Devane E, Horstmann I, Viollat L, Foster-Dyer R, Le Bohec C, Zitterbart D, Houstin A, Richter S, Winterl A, Wienecke B, Salas L, Nixon M, Barbraud C, Kooyman G, Ponganis P, Ainley D, Trathan P, Jenouvrier S. Advances in remote sensing of emperor penguins: first multi-year time series documenting trends in the global population. Proc Biol Sci 2024; 291:20232067. [PMID: 38471550 PMCID: PMC10932703 DOI: 10.1098/rspb.2023.2067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 02/15/2024] [Indexed: 03/14/2024] Open
Abstract
Like many polar animals, emperor penguin populations are challenging to monitor because of the species' life history and remoteness. Consequently, it has been difficult to establish its global status, a subject important to resolve as polar environments change. To advance our understanding of emperor penguins, we combined remote sensing, validation surveys and using Bayesian modelling, we estimated a comprehensive population trajectory over a recent 10-year period, encompassing the entirety of the species' range. Reported as indices of abundance, our study indicates with 81% probability that there were fewer adult emperor penguins in 2018 than in 2009, with a posterior median decrease of 9.6% (95% credible interval (CI) -26.4% to +9.4%). The global population trend was -1.3% per year over this period (95% CI = -3.3% to +1.0%) and declines probably occurred in four of eight fast ice regions, irrespective of habitat conditions. Thus far, explanations have yet to be identified regarding trends, especially as we observed an apparent population uptick toward the end of time series. Our work potentially establishes a framework for monitoring other Antarctic coastal species detectable by satellite, while promoting a need for research to better understand factors driving biotic changes in the Southern Ocean ecosystem.
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Affiliation(s)
- Michelle LaRue
- Department of Earth and Environmental Science, University of Minnesota, Minneapolis, MN, USA
- School of Earth and Environment, University of Canterbury, Christchurch, New Zealand
| | - David Iles
- Canadian Wildlife Service, Environment and Climate Change Canada, Ottawa, Canada
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Sara Labrousse
- Department of Earth and Environmental Science, University of Minnesota, Minneapolis, MN, USA
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
- Sorbonne Université, LOCEAN-IPSL, UMR 7159, 75005, Paris, France
| | | | - David Ortega
- Department of Earth and Environmental Science, University of Minnesota, Minneapolis, MN, USA
| | - Eileen Devane
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | | | - Lise Viollat
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Rose Foster-Dyer
- School of Earth and Environment, University of Canterbury, Christchurch, New Zealand
| | - Céline Le Bohec
- Centre National de la Recherche Scientifique, Université de Strasbourg, IPHC UMR 7178, Strasbourg, France
- Département de Biologie Polaire, Centre Scientifique de Monaco, Monaco City, Monaco
| | - Daniel Zitterbart
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
- Department of Physics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Aymeric Houstin
- Centre National de la Recherche Scientifique, Université de Strasbourg, IPHC UMR 7178, Strasbourg, France
- Département de Biologie Polaire, Centre Scientifique de Monaco, Monaco City, Monaco
- Department of Physics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Sebastian Richter
- Department of Physics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Alexander Winterl
- Department of Physics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Barbara Wienecke
- Department of Climate Change, Energy, the Environment and Water, Australian Antarctic Division, Hobart, Australia
| | - Leo Salas
- Point Blue Conservation Science, Petaluma, CA, USA
| | - Monique Nixon
- School of Earth and Environment, University of Canterbury, Christchurch, New Zealand
| | - Christophe Barbraud
- Centre d'Etudes Biologiques de Chizé, UMR7372 Centre National de la Recherche Scientifique – La Rochelle Université, 79360 Villiers en Bois, France
| | | | - Paul Ponganis
- Scripps Institution of Oceanography, La Jolla, CA, USA
| | | | - Philip Trathan
- British Antarctic Survey, Cambridge, UK
- Ocean and Earth Science, National Oceanography Centre, University of Southampton, University Road, Southampton SO17 1BJ, UK
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2
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Varliero G, Lebre PH, Adams B, Chown SL, Convey P, Dennis PG, Fan D, Ferrari B, Frey B, Hogg ID, Hopkins DW, Kong W, Makhalanyane T, Matcher G, Newsham KK, Stevens MI, Weigh KV, Cowan DA. Biogeographic survey of soil bacterial communities across Antarctica. MICROBIOME 2024; 12:9. [PMID: 38212738 PMCID: PMC10785390 DOI: 10.1186/s40168-023-01719-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 11/11/2023] [Indexed: 01/13/2024]
Abstract
BACKGROUND Antarctica and its unique biodiversity are increasingly at risk from the effects of global climate change and other human influences. A significant recent element underpinning strategies for Antarctic conservation has been the development of a system of Antarctic Conservation Biogeographic Regions (ACBRs). The datasets supporting this classification are, however, dominated by eukaryotic taxa, with contributions from the bacterial domain restricted to Actinomycetota and Cyanobacteriota. Nevertheless, the ice-free areas of the Antarctic continent and the sub-Antarctic islands are dominated in terms of diversity by bacteria. Our study aims to generate a comprehensive phylogenetic dataset of Antarctic bacteria with wide geographical coverage on the continent and sub-Antarctic islands, to investigate whether bacterial diversity and distribution is reflected in the current ACBRs. RESULTS Soil bacterial diversity and community composition did not fully conform with the ACBR classification. Although 19% of the variability was explained by this classification, the largest differences in bacterial community composition were between the broader continental and maritime Antarctic regions, where a degree of structural overlapping within continental and maritime bacterial communities was apparent, not fully reflecting the division into separate ACBRs. Strong divergence in soil bacterial community composition was also apparent between the Antarctic/sub-Antarctic islands and the Antarctic mainland. Bacterial communities were partially shaped by bioclimatic conditions, with 28% of dominant genera showing habitat preferences connected to at least one of the bioclimatic variables included in our analyses. These genera were also reported as indicator taxa for the ACBRs. CONCLUSIONS Overall, our data indicate that the current ACBR subdivision of the Antarctic continent does not fully reflect bacterial distribution and diversity in Antarctica. We observed considerable overlap in the structure of soil bacterial communities within the maritime Antarctic region and within the continental Antarctic region. Our results also suggest that bacterial communities might be impacted by regional climatic and other environmental changes. The dataset developed in this study provides a comprehensive baseline that will provide a valuable tool for biodiversity conservation efforts on the continent. Further studies are clearly required, and we emphasize the need for more extensive campaigns to systematically sample and characterize Antarctic and sub-Antarctic soil microbial communities. Video Abstract.
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Affiliation(s)
- Gilda Varliero
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, 0002, South Africa
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, 8903, Birmensdorf, Switzerland
| | - Pedro H Lebre
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, 0002, South Africa
| | - Byron Adams
- Department of Biology, Brigham Young University, Provo, UT, 84602, USA
- Monte L. Bean Life Science Museum, Brigham Young University, Provo, UT, 84602, USA
| | - Steven L Chown
- Securing Antarctica's Environmental Future, School of Biological Sciences, Monash University, Clayton, VA, 3800, Australia
| | - Peter Convey
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
- Department of Zoology, University of Johannesburg, PO Box 524, Auckland Park, 2006, South Africa
- Biodiversity of Antarctic and Sub-Antarctic Ecosystems (BASE), Santiago, Chile
| | - Paul G Dennis
- School of the Environment, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Dandan Fan
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Belinda Ferrari
- School of Biotechnology and Biomolecular Sciences, University of NSW, Sydney, NSW, 2052, Australia
| | - Beat Frey
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, 8903, Birmensdorf, Switzerland
| | - Ian D Hogg
- School of Science, University of Waikato, Hamilton, New Zealand
- Canadian High Arctic Research Station, Polar Knowledge Canada, Cambridge Bay, NU, Canada
| | - David W Hopkins
- SRUC - Scotland's Rural College, West Mains Road, Edinburgh, EH9 3JG, Scotland, UK
| | - Weidong Kong
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Thulani Makhalanyane
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, 0002, South Africa
| | - Gwynneth Matcher
- Department of Biochemistry and Microbiology, Rhodes University, Makhanda, South Africa
| | - Kevin K Newsham
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - Mark I Stevens
- Securing Antarctica's Environmental Future, Earth and Biological Sciences, South Australian Museum, Adelaide, SA, 5000, Australia
- School of Biological Sciences, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Katherine V Weigh
- School of the Environment, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Don A Cowan
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, 0002, South Africa.
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3
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Forcada J, Hoffman JI, Gimenez O, Staniland IJ, Bucktrout P, Wood AG. Ninety years of change, from commercial extinction to recovery, range expansion and decline for Antarctic fur seals at South Georgia. GLOBAL CHANGE BIOLOGY 2023; 29:6867-6887. [PMID: 37839801 DOI: 10.1111/gcb.16947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 10/17/2023]
Abstract
With environmental change, understanding how species recover from overharvesting and maintain viable populations is central to ecosystem restoration. Here, we reconstruct 90 years of recovery trajectory of the Antarctic fur seal at South Georgia (S.W. Atlantic), a key indicator species in the krill-based food webs of the Southern Ocean. After being harvested to commercial extinction by 1907, this population rebounded and now constitutes the most abundant otariid in the World. However, its status remains uncertain due to insufficient and conflicting data, and anthropogenic pressures affecting Antarctic krill, an essential staple for millions of fur seals and other predators. Using integrated population models, we estimated simultaneously the long-term abundance for Bird Island, northwest South Georgia, epicentre of recovery of the species after sealing, and population adjustments for survey counts with spatiotemporal applicability. Applied to the latest comprehensive survey data, we estimated the population at South Georgia in 2007-2009 as 3,510,283 fur seals [95% CI: 3,140,548-3,919,604] (ca. 98% of global population), after 40 years of maximum growth and range expansion owing to an abundant krill supply. At Bird Island, after 50 years of exponential growth followed by 25 years of slow stable growth, the population collapsed in 2009 and has thereafter declined by -7.2% [-5.2, -9.1] per annum, to levels of the 1970s. For the instrumental record, this trajectory correlates with a time-varying relationship between coupled climate and sea surface temperature cycles associated with low regional krill availability, although the effects of increasing krill extraction by commercial fishing and natural competitors remain uncertain. Since 2015, fur seal longevity and recruitment have dropped, sexual maturation has retarded, and population growth is expected to remain mostly negative and highly variable. Our analysis documents the rise and fall of a key Southern Ocean predator over a century of profound environmental and ecosystem change.
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Affiliation(s)
- Jaume Forcada
- British Antarctic Survey, Natural Environment Research Council, UKRI, Cambridge, UK
| | - Joseph I Hoffman
- British Antarctic Survey, Natural Environment Research Council, UKRI, Cambridge, UK
- Department of Animal Behavior, University of Bielefeld, Bielefeld, Germany
| | - Olivier Gimenez
- CEFE, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France
| | | | - Pete Bucktrout
- British Antarctic Survey, Natural Environment Research Council, UKRI, Cambridge, UK
| | - Andrew G Wood
- British Antarctic Survey, Natural Environment Research Council, UKRI, Cambridge, UK
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4
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Labrousse S, Nerini D, Fraser AD, Salas L, Sumner M, Le Manach F, Jenouvrier S, Iles D, LaRue M. Where to live? Landfast sea ice shapes emperor penguin habitat around Antarctica. SCIENCE ADVANCES 2023; 9:eadg8340. [PMID: 37756400 PMCID: PMC10530227 DOI: 10.1126/sciadv.adg8340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023]
Abstract
Predicting species survival in the face of climate change requires understanding the drivers that influence their distribution. Emperor penguins (Aptenodytes forsteri) incubate and rear chicks on landfast sea ice, whose extent, dynamics, and quality are expected to vary substantially due to climate change. Until recently, this species' continent-wide observations were scarce, and knowledge on their distribution and habitat limited. Advances in satellite imagery now allow their observation and characterization of habitats across Antarctica at high resolution. Using circumpolar high-resolution satellite images, unique fast ice metrics, and geographic and biological factors, we identified diverse penguin habitats across the continent, with no significant difference between areas with penguins or not. There is a clear geographic partitioning of colonies with respect to their defining habitat characteristics, indicating possible behavioral plasticity among different metapopulations. This coincides with geographic structures found in previous genetic studies. Given projections of quasi-extinction for this species in 2100, this study provides essential information for conservation measures.
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Affiliation(s)
- Sara Labrousse
- Laboratoire d’Océanographie et du Climat: Expérimentations et approches numériques (LOCEAN), UMR 7159 Sorbonne-Université, CNRS, MNHN, IRD, IPSL, 75005 Paris, France
| | - David Nerini
- Mediterranean Institute of Oceanography, MIO, Aix-Marseille University, Marseille, France
| | - Alexander D. Fraser
- Australian Antarctic Program Partnership, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania
| | | | - Michael Sumner
- Integrated Digital East Antarctica, Australian Antarctic Division, Channel Highway, Kingston, Tasmania 7050, Australia
| | | | - Stephanie Jenouvrier
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - David Iles
- Canadian Wildlife Service, Environment and Climate Change Canada, Ottawa, Canada
| | - Michelle LaRue
- Department of Earth and Environmental Science, University of Minnesota, Minneapolis, MN, USA
- School of Earth and Environment, University of Canterbury, Christchurch, New Zealand
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5
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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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6
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Wu Z, Zhang C, Gu X, Duporge I, Hughey LF, Stabach JA, Skidmore AK, Hopcraft JGC, Lee SJ, Atkinson PM, McCauley DJ, Lamprey R, Ngene S, Wang T. Deep learning enables satellite-based monitoring of large populations of terrestrial mammals across heterogeneous landscape. Nat Commun 2023; 14:3072. [PMID: 37244940 DOI: 10.1038/s41467-023-38901-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 05/19/2023] [Indexed: 05/29/2023] Open
Abstract
New satellite remote sensing and machine learning techniques offer untapped possibilities to monitor global biodiversity with unprecedented speed and precision. These efficiencies promise to reveal novel ecological insights at spatial scales which are germane to the management of populations and entire ecosystems. Here, we present a robust transferable deep learning pipeline to automatically locate and count large herds of migratory ungulates (wildebeest and zebra) in the Serengeti-Mara ecosystem using fine-resolution (38-50 cm) satellite imagery. The results achieve accurate detection of nearly 500,000 individuals across thousands of square kilometers and multiple habitat types, with an overall F1-score of 84.75% (Precision: 87.85%, Recall: 81.86%). This research demonstrates the capability of satellite remote sensing and machine learning techniques to automatically and accurately count very large populations of terrestrial mammals across a highly heterogeneous landscape. We also discuss the potential for satellite-derived species detections to advance basic understanding of animal behavior and ecology.
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Affiliation(s)
- Zijing Wu
- Department of Natural Resources, Faculty of Geo-Information Science and Earth Observation, University of Twente, Enschede, The Netherlands
| | - Ce Zhang
- Lancaster Environment Center, Lancaster University, Lancaster, UK
- UK Centre for Ecology & Hydrology, Lancaster, UK
| | - Xiaowei Gu
- School of Computing, University of Kent, Canterbury, UK
| | - Isla Duporge
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- U.S. Army Research Laboratory, Army Research Office, Durham, NC, USA
- The National Academies of Sciences, Washington, D.C., USA
| | - Lacey F Hughey
- Conservation Ecology Center, Smithsonian National Zoo and Conservation Biology Institute, Front Royal, VA, USA
| | - Jared A Stabach
- Conservation Ecology Center, Smithsonian National Zoo and Conservation Biology Institute, Front Royal, VA, USA
| | - Andrew K Skidmore
- Department of Natural Resources, Faculty of Geo-Information Science and Earth Observation, University of Twente, Enschede, The Netherlands
- School of Natural Sciences, Macquarie University, Sydney, NSW, Australia
| | - J Grant C Hopcraft
- Institute of Biodiversity, Animal Health, and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Stephen J Lee
- U.S. Army Research Laboratory, Army Research Office, Durham, NC, USA
| | - Peter M Atkinson
- Lancaster Environment Center, Lancaster University, Lancaster, UK
- Geography and Environmental Science, University of Southampton, Southampton, UK
| | - Douglas J McCauley
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, USA
| | - Richard Lamprey
- Department of Natural Resources, Faculty of Geo-Information Science and Earth Observation, University of Twente, Enschede, The Netherlands
| | - Shadrack Ngene
- Wildlife Research and Training Institute, Naivasha, Kenya
| | - Tiejun Wang
- Department of Natural Resources, Faculty of Geo-Information Science and Earth Observation, University of Twente, Enschede, The Netherlands.
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7
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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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8
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Goetz KT, Dinniman MS, Hückstädt LA, Robinson PW, Shero MR, Burns JM, Hofmann EE, Stammerjohn SE, Hazen EL, Ainley DG, Costa DP. Seasonal habitat preference and foraging behaviour of post-moult Weddell seals in the western Ross Sea. ROYAL SOCIETY OPEN SCIENCE 2023; 10:220500. [PMID: 36704255 PMCID: PMC9874274 DOI: 10.1098/rsos.220500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 01/05/2023] [Indexed: 06/18/2023]
Abstract
Weddell seals (Leptonychotes weddellii) are important predators in the Southern Ocean and are among the best-studied pinnipeds on Earth, yet much still needs to be learned about their year-round movements and foraging behaviour. Using biologgers, we tagged 62 post-moult Weddell seals in McMurdo Sound and vicinity between 2010 and 2012. Generalized additive mixed models were used to (i) explain and predict the probability of seal presence and foraging behaviour from eight environmental variables, and (ii) examine foraging behaviour in relation to dive metrics. Foraging probability was highest in winter and lowest in summer, and foraging occurred mostly in the water column or just above the bottom; across all seasons, seals preferentially exploited the shallow banks and deeper troughs of the Ross Sea, the latter providing a pathway for Circumpolar Deep Water to flow onto the shelf. In addition, the probability of Weddell seal occurrence and foraging increased with increasing bathymetric slope and where water depth was typically less than 600 m. Although the probability of occurrence was higher closer to the shelf break, foraging was higher in areas closer to shore and over banks. This study highlights the importance of overwinter foraging for recouping body mass lost during the previous summer.
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Affiliation(s)
- Kimberly T. Goetz
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, WA 98115, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 100 Shaffer Road, Santa Cruz, CA 95060, USA
| | - Michael S. Dinniman
- Center for Coastal Physical Oceanography, Old Dominion University, 4111 Monarch Way, 3 floor, Norfolk, VA 23508 USA
| | - Luis A. Hückstädt
- Center for Ecology and Conservation, University of Exeter, Penryn TR10 9FE, UK
| | - Patrick W. Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 100 Shaffer Road, Santa Cruz, CA 95060, USA
| | - Michelle R. Shero
- Biology Department, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543 USA
| | - Jennifer M. Burns
- Department of Biological Sciences, Texas Tech University, Box 43131, Lubbock, TX 79409, USA
| | - Eileen E. Hofmann
- Center for Coastal Physical Oceanography, Old Dominion University, 4111 Monarch Way, 3 floor, Norfolk, VA 23508 USA
| | - Sharon E. Stammerjohn
- Institute of Arctic and Alpine Research, University of Colorado, Campus Box 450, Boulder, CO 80309-0450, USA
| | - Elliott L. Hazen
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 100 Shaffer Road, Santa Cruz, CA 95060, USA
- Environmental Research Division, Southwest Fisheries Science Center, National Oceanographic and Atmospheric Administration, 99 Pacific Street, Suite 255A, Monterey, CA 93940, USA
| | - David G. Ainley
- H.T. Harvey and Associates Ecological Consultants, 983 University Avenue, Building D, Los Gatos, CA 95032, USA
| | - Daniel P. Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 100 Shaffer Road, Santa Cruz, CA 95060, USA
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9
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Koerich G, Fraser CI, Lee CK, Morgan FJ, Tonkin JD. Forecasting the future of life in Antarctica. Trends Ecol Evol 2023; 38:24-34. [PMID: 35934551 DOI: 10.1016/j.tree.2022.07.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/12/2022] [Accepted: 07/15/2022] [Indexed: 12/24/2022]
Abstract
Antarctic ecosystems are under increasing anthropogenic pressure, but efforts to predict the responses of Antarctic biodiversity to environmental change are hindered by considerable data challenges. Here, we illustrate how novel data capture technologies provide exciting opportunities to sample Antarctic biodiversity at wider spatiotemporal scales. Data integration frameworks, such as point process and hierarchical models, can mitigate weaknesses in individual data sets, improving confidence in their predictions. Increasing process knowledge in models is imperative to achieving improved forecasts of Antarctic biodiversity, which can be attained for data-limited species using hybrid modelling frameworks. Leveraging these state-of-the-art tools will help to overcome many of the data scarcity challenges presented by the remoteness of Antarctica, enabling more robust forecasts both near- and long-term.
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Affiliation(s)
- Gabrielle Koerich
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
| | - Ceridwen I Fraser
- Department of Marine Science, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Charles K Lee
- International Centre for Terrestrial Antarctic Research, School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand
| | - Fraser J Morgan
- Manaaki Whenua - Landcare Research, Auckland 1072, New Zealand; Te Pūnaha Matatini, Centre of Research Excellence in Complex Systems, Auckland, New Zealand
| | - Jonathan D Tonkin
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand; Te Pūnaha Matatini, Centre of Research Excellence in Complex Systems, Auckland, New Zealand; Bioprotection Aotearoa, Centre of Research Excellence, Canterbury, New Zealand.
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10
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Whoriskey S, Pearson LE, Harris HS, Whitmer ER, Liwanag HEM, Brodie E, Johnson S. Using a combination of midazolam and butorphanol is a safe and effective reversible field sedation protocol for Weddell seal (Leptonychotes weddellii) pups. Vet Rec 2022; 191:e2238. [PMID: 36251215 DOI: 10.1002/vetr.2238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 07/31/2022] [Accepted: 09/02/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND Weddell seals (Leptonychotes weddellii) are a well-studied species of phocid with an apparent sensitivity to immobilising agents. Mortality as high as 31% has been reported during field immobilisation. This study investigated the use of a benzodiazepine in combination with an opioid agonist/antagonist for sedation in Weddell seal pups as part of a physiological study. METHODS During the 2017 and 2019 Antarctic pupping seasons, 18 Weddell seal pups were sedated by intramuscular administration of a combination of midazolam and butorphanol or intravenous midazolam alone. Individuals were sedated at 1, 3, 5 and 7 weeks of age. Naltrexone and flumazenil were used to reverse sedation. The combination was 100% effective in providing appropriate sedation for the intended procedures. RESULTS Analyses were performed to investigate relationships between dose administered, age, individual reactions, adverse effects and changes in dive physiology. Transient apnoea (10-60 seconds) was the most frequently observed adverse effect. No sedation-associated morbidity or mortality occurred. LIMITATIONS The sample size is small and there is no pharmacokinetic information for either sedative or reversal in phocid species. CONCLUSIONS The combination of midazolam (0.2-0.3 mg/kg) and butorphanol (0.1-0.2 mg/kg) provided safe and effective sedation, with reversible effects, in Weddell seal pups.
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Affiliation(s)
| | - Linnea E Pearson
- California Polytechnic State University, San Luis Obispo, California, USA
| | - Heather S Harris
- The Marine Mammal Center, Sausalito, California, USA.,California Polytechnic State University, San Luis Obispo, California, USA
| | | | | | - Erin Brodie
- The Marine Mammal Center, Sausalito, California, USA
| | - Shawn Johnson
- The Marine Mammal Center, Sausalito, California, USA.,Sea Change Health, Sunnyvale, California, USA
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11
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Rodofili EN, Lecours V, LaRue M. Remote sensing techniques for automated marine mammals detection: a review of methods and current challenges. PeerJ 2022; 10:e13540. [PMID: 35757165 PMCID: PMC9220915 DOI: 10.7717/peerj.13540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/13/2022] [Indexed: 01/17/2023] Open
Abstract
Marine mammals are under pressure from multiple threats, such as global climate change, bycatch, and vessel collisions. In this context, more frequent and spatially extensive surveys for abundance and distribution studies are necessary to inform conservation efforts. Marine mammal surveys have been performed visually from land, ships, and aircraft. These methods can be costly, logistically challenging in remote locations, dangerous to researchers, and disturbing to the animals. The growing use of imagery from satellite and unoccupied aerial systems (UAS) can help address some of these challenges, complementing crewed surveys and allowing for more frequent and evenly distributed surveys, especially for remote locations. However, manual counts in satellite and UAS imagery remain time and labor intensive, but the automation of image analyses offers promising solutions. Here, we reviewed the literature for automated methods applied to detect marine mammals in satellite and UAS imagery. The performance of studies is quantitatively compared with metrics that evaluate false positives and false negatives from automated detection against manual counts of animals, which allows for a better assessment of the impact of miscounts in conservation contexts. In general, methods that relied solely on statistical differences in the spectral responses of animals and their surroundings performed worse than studies that used convolutional neural networks (CNN). Despite mixed results, CNN showed promise, and its use and evaluation should continue. Overall, while automation can reduce time and labor, more research is needed to improve the accuracy of automated counts. With the current state of knowledge, it is best to use semi-automated approaches that involve user revision of the output. These approaches currently enable the best tradeoff between time effort and detection accuracy. Based on our analysis, we identified thermal infrared UAS imagery as a future research avenue for marine mammal detection and also recommend the further exploration of object-based image analysis (OBIA). Our analysis also showed that past studies have focused on the automated detection of baleen whales and pinnipeds and that there is a gap in studies looking at toothed whales, polar bears, sirenians, and mustelids.
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Affiliation(s)
- Esteban N. Rodofili
- School of Natural Resources and Environment, University of Florida, Gainesville, FL, United States of America
| | - Vincent Lecours
- School of Natural Resources and Environment, University of Florida, Gainesville, FL, United States of America,School of Forest, Fisheries, and Geomatics Sciences, University of Florida, Gainesville, FL, United States of America
| | - Michelle LaRue
- School of Earth and Environment, University of Canterbury, Christchurch, New Zealand,Department of Earth and Environmental Science, University of Minnesota, Minneapolis, MN, United States of America
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12
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Patterson QM, Kraberger S, Martin DP, Shero MR, Beltran RS, Kirkham AL, Aleamotu'a M, Ainley DG, Kim S, Burns JM, Varsani A. Circoviruses and cycloviruses identified in Weddell seal fecal samples from McMurdo Sound, Antarctica. INFECTION GENETICS AND EVOLUTION 2021; 95:105070. [PMID: 34481994 DOI: 10.1016/j.meegid.2021.105070] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/28/2021] [Accepted: 09/01/2021] [Indexed: 11/19/2022]
Abstract
Circoviridae is a family of circular single-stranded DNA viruses whose members infect a wide variety of hosts. While well characterized in avian and mammalian hosts, little is known about circoviruses associated with Antarctic animals. From 48 Weddell seal (Leptonychotes weddellii) fecal samples collected on the sea ice in McMurdo between Nov 2014 and Dec 2014, we identified and determined the genomes of novel viruses that fall within two genera of the family Circoviridae, i.e. Circovirus (n = 7) and Cyclovirus (n = 45). We named these viruses as werosea circovirus (WerCV) and werosea cyclovirus (WerCyV). The genomes of WerCV and WerCyV share ~63-64% genome-wide pairwise identity with classified circoviruses and cycloviruses, respectively. Based on the species demarcation threshold of 80% for members of the Circoviridae, the genomes of WerCV and WerCyV represent new species in their respective genera. Evidence indicated recombination in five of the 45 WerCyV genomes identified in this study. These are the first circoviruses found associated with Antarctic pinnipeds, adding to those recently identified associated with Adélie (Pygoscelis adeliae) and chinstrap penguins (P. antarcticus).
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Affiliation(s)
- Quinn M Patterson
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Simona Kraberger
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Darren P Martin
- Computational Biology Division, Department of Integrative Biomedical Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Observatory, 7925, South Africa
| | - Michelle R Shero
- Biology Department, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, MA 02543, USA
| | - Roxanne S Beltran
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 130 McAllister Way, Santa Cruz, CA 95060, USA
| | - Amy L Kirkham
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 17101 Point Lena Loop Road, Juneau, AK 99801, USA
| | - Maketalena Aleamotu'a
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
| | | | - Stacy Kim
- Moss Landing Marine Laboratories, Moss Landing, CA 95039, USA
| | - Jennifer M Burns
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA.
| | - Arvind Varsani
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA; Structural Biology Research Unit, Department of Integrative Biomedical Sciences, University of Cape Town, 7925 Cape Town, South Africa.
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