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Link to original content: https://pubmed.ncbi.nlm.nih.gov/34559555
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. 2021 Sep 24;7(39):eabh3674.
doi: 10.1126/sciadv.abh3674. Epub 2021 Sep 24.

Insights from the first global population estimate of Weddell seals in Antarctica

Michelle LaRue  1   2 , Leo Salas  3 , Nadav Nur  3 , David Ainley  4 , Sharon Stammerjohn  5 , Jean Pennycook  4 , Melissa Dozier  6 , Jon Saints  7 , Kostas Stamatiou  7 , Luke Barrington  8 , Jay Rotella  9
Affiliations

Insights from the first global population estimate of Weddell seals in Antarctica

Michelle LaRue et al. Sci Adv. .

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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Figures

Fig. 1.
Fig. 1.. A map of WESE populations around Antarctica during November 2011.
Map of WESE abundance (females only) on fast ice around Antarctica during November 2011 (excluding the northern portion of the western Antarctic Peninsula, where fast ice has disappeared or is decreasing), estimated through a combination of VHR images and crowd-sourcing counts of seals. Numbers of animals across tagging campaigns are referenced in Table 1, including the estimated stable age distribution, based on ground validation from Erebus Bay, Antarctica [e.g., (20)]. The Underlying image is the Reference Elevation Model of Antarctica provided by the Polar Geospatial Center in collaboration with Ohio State University, the National Geospatial Intelligence Agency, and the National Science Foundation.
Fig. 2.
Fig. 2.. A two-dimensional partial dependence plot showing the effect of the size of the nearest EMPE colony on the probability of WESE presence on Antarctic fast ice.
Two-dimensional partial dependence plot showing the combined effect of EMPE abundance (logEMPEabund) and distance to the nearest EMPE colony (logEMPEdist) on the probability of presence of WESEs around the fast ice of Antarctica during November 2011. WESEs are more likely to be found close to smaller (<100 breeding pairs) EMPE colonies.
Fig. 3.
Fig. 3.. A partial dependence plot showing the effect of ADPEs on the probability of WESE presence on Antarctic fast ice.
Partial dependence plot showing the effect of ADPE distance on the probability of WESE presence around Antarctic fast ice during November 2011 for each of the four oceanographic regions defined in this paper. Regions (n = 4) are defined in Fig. 4.
Fig. 4.
Fig. 4.. Regional boundaries for modeling WESE presence in Antarctica.
Four regions around Antarctica outlined in red for habitat modeling of WESEs around the continent, with exception of the northern part of the western Antarctic Peninsula. We defined regions irrespective of animal presence and considered regions exclusively based on oceanographic features such as currents, gyres, bathymetry, and general pack ice dynamics.
See this image and copyright information in PMC

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References

    1. Estes J. A., Terborgh J., Brashares J. S., Power M. E., Berger J., Bond W. J., Carpenter S. R., Essington T. E., Holt R. D., Jackson J. B. C., Marquis R. J., Oksanen L., Oksanen T., Paine R. T., Pikitch E. K., Ripple W. J., Sandin S. A., Scheffer M., Schoener T. W., Shurin J. B., Sinclair A. R. E., Soulé M. E., Virtanen R., Wardle D. A., Trophic downgrading of planet Earth. Science 333, 301–306 (2011). - PubMed
    1. Paleczny M., Hammill E., Karpouzi V., Pauly D., Population trend of the world’s monitored seabirds, 1950-2010. PLOS ONE 10, e0129342 (2015). - PMC - PubMed
    1. Koch P. L., Zachos J. C., Gingerich P. D., Correlation between isotope records in marine and continental carbon reservoirs near the Palaeocene/Eocene boundary. Nature 358, 319–322 (1992).
    1. Hofman R. J., Stopping overexploitation of living resources on the high seas. Mar. Policy 103, 91–100 (2019).
    1. Trathan P. N., Wienecke B., Barbraud C., Jenouvrier S., Kooyman G., Le Bohec C., Ainley D. G., Ancel A., Zitterbart D. P., Chown S. L., LaRue M., Cristofari R., Younger J., Clucas G., Bost C. A., Brown J. A., Gillett H. J., Fretwell P. T., The emperor penguin - Vulnerable to projected rates of warming and sea ice loss. Biol. Conserv. 241, 108216 (2020).