Rapid Population Collapse of a Key Marine Predator in the Northern Antarctic Peninsula - Antarctic Fur Seal Population Dynamics

Description

Antarctic fur seals (AFS) are an ecologically important predator and a focal indicator species for ecosystem-based Antarctic fisheries management. This species suffered intensive anthropogenic exploitation until the early 1900s, but recolonized most of its former distribution, including the southern-most colony at Cape Shirreff, South Shetland Islands (SSI). The IUCN describes a single, global AFS population of least concern; however, extensive genetic analyses clearly identify four distinct breeding stocks, including one in the SSI. To update the population status of SSI AFS, we analyzed 20 years of field-based data including population counts, body size and condition, natality, recruitment, foraging behaviors, return rates, and pup mortality at the largest SSI colony. Our findings show a precipitous decline in AFS abundance (86% decrease since 2007), likely driven by leopard seal predation (increasing since 2001, p << 0.001) and potentially worsening summer foraging conditions. We estimated that leopard seals consumed an average of 69.3% (range: 50.3–80.9%) of all AFS pups born each year since 2010. AFS foraging-trip durations, an index of their foraging habitat quality, were consistent with decreasing krill and fish availability. Significant improvement in the age-specific over-winter body condition of AFS indicates that observed population declines are driven by processes local to the northern Antarctic Peninsula. The loss of SSI AFS would substantially reduce the genetic diversity of the species, and decrease its resilience to climate change. There is an urgent need to reevaluate the conservation status of Antarctic fur seals, particularly for the rapidly declining SSI population.

Resources

Name Format Description Link
0 https://www.frontiersin.org/articles/10.3389/fmars.2021.796488/full#supplementary-material
0 NOAA, NMFS, SWFSC, Antarctic Ecosystem Research Division https://www.fisheries.noaa.gov/about/antarctic-ecosystem-research-division-southwest-fisheries-science-center
33 NOAA Data Management Plan for this record on InPort. https://www.fisheries.noaa.gov/inportserve/waf/noaa/nmfs/swfsc/dmp/pdf/66326.pdf
0 View the complete metadata record on InPort for more information about this dataset. https://www.fisheries.noaa.gov/inport/item/66326
0 The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. https://www.earthdata.nasa.gov/learn/find-data/idn/gcmd-keywords

Tags

  • antarctic fur seal
  • conservation status
  • south shetland islands
  • cape shirreff
  • edge population
  • continent
  • antarctica
  • arctocephalus gazella
  • doc/noaa/nmfs/swfsc
  • antarctic peninsula
  • national marine fisheries service
  • livingston island
  • noaa. u.s. department of commerce
  • top-down and bottom-up control
  • southwest fisheries science center
  • san telmo islets
  • amlr predator data
  • population dynamics (ecology)

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