South Shetland Antarctic fur seal pup census

Sampling event Observation
Latest version published by SCAR - AntOBIS on May 27, 2025 SCAR - AntOBIS
Publication date:
27 May 2025
Published by:
SCAR - AntOBIS
License:
CC0 1.0

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Description

The South Shetland Antarctic fur seal pup census dataset is part of long-term monitoring efforts in the South Shetland Islands archipelago (SSI), based at Cape Shirreff, Livingston Island. These efforts, which include conducting annual synoptic census counts of South Shetland Antarctic fur seals (SSAFS) throughout the region, have been primarily carried out by the Chilean Antarctic Institute (INACH) and the National Oceanic and Atmospheric Administration (NOAA) United States Antarctic Marine Living Resources Program (U.S. AMLR). These census data will continue to be collected by the U.S. AMLR program, and updated yearly.Recent studies have demonstrated Antarctic fur seals (Arctocephalus gazella) are composed of at least four distinct subpopulations (Bonin et al. 2013, Paijmans et al. 2020), including one breeding throughout the SSI. These SSAFS are the highest latitude population of otariids in the world. As such, this subpopulation faces a unique array of environmental and ecological challenges, harbors a disproportionately large reservoir of genetic diversity for the species, and has experienced catastrophic population decline between 2008 and 2023 (Krause et al. 2023 and references therein). Therefore, ensuring access to accurate and updated population data for SSAFS is particularly important for managers and decision makers. Due to regular absences by foraging females throughout the breeding season, and the irregular haul out patterns of males and subadults, the most informative measure of fur seal population size is to annually count pups (Payne, 1979; Bengtson et al., 1990). This dataset consists of all known total synoptic Antarctic fur seal pup counts (i.e., live and dead pups) from the SSI during the austral summers since 1959. Counts from the subset breeding colonies at Cape Shirreff (CS, reported with standard deviation (±SD) where available) and the San Telmo Islets (STI) are also included. Data were collected by the U.S. AMLR Program, unless otherwise indicated.Most of these annual census counts were conducted during the optimal biological window (late December and early January) when the vast majority of pups are born, but have not yet been subject to substantial mortality (Krause et al. 2022). The authors are confident that all counts included in this dataset are comparable and representative of South Shetland Antarctic fur seal population trends. However, census dates, or at least best estimates of the census date, are included for all records for any parties wishing to apply correction factors.The data are published as a standardized Darwin Core Archive, which contains count data for SSAFS pups from the specified locations during the specified seasons. This dataset is published under the license CC0. Please follow the guidelines from the SCAR Data Policy (SCAR, 2023) when using the data. If you have any questions regarding this dataset, please contact us via the contact information provided in the metadata or via data-biodiversity-aq@naturalsciences.be. Issues with the dataset can be reported at https://github.com/us-amlr/ssafs-pup-census.This dataset is maintained by the U.S. Antarctic Marine Living Resources Program, funded by NOAA.

Data Records

The data in this sampling event resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 60 records.

1 extension data tables also exist. An extension record supplies extra information about a core record. The number of records in each extension data table is illustrated below.

Event (core)
60
Occurrence 
60

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.

Versions

The table below shows only published versions of the resource that are publicly accessible.

How to cite

Researchers should cite this work as follows:

Krause D J, Woodman S M, Goebel M E (2025). South Shetland Antarctic fur seal pup census. Version 1.2. SCAR - AntOBIS. Samplingevent dataset. https://ipt-obis.gbif.us/resource?r=usamlr-ssafs-pup-census&v=1.2

Rights

Researchers should respect the following rights statement:

The publisher and rights holder of this work is SCAR - AntOBIS. To the extent possible under law, the publisher has waived all rights to these data and has dedicated them to the Public Domain (CC0 1.0). Users may copy, modify, distribute and use the work, including for commercial purposes, without restriction.

GBIF Registration

This resource has been registered with GBIF, and assigned the following GBIF UUID: a02013f1-2eb2-4ecd-8f56-a455cbedce17.  SCAR - AntOBIS publishes this resource, and is itself registered in GBIF as a data publisher endorsed by Ocean Biodiversity Information System.

Keywords

Samplingevent; Observation; OCEAN; SOUTHERN OCEAN; ANTARCTICA; MARINE MAMMALS; PINNIPED; BIOGEOGRAPHY; census count data

Contacts

Douglas J. Krause
  • Originator ●
  • Point Of Contact
U.S. Antarctic Marine Living Resources Program, Ecosystem Science Division, Southwest Fisheries Science Center, NOAA Fisheries
US
Samuel M. Woodman
  • Metadata Provider ●
  • Originator
U.S. Antarctic Marine Living Resources Program, Ecosystem Science Division, Southwest Fisheries Science Center, NOAA Fisheries
US
Michael E. Goebel
  • Originator
Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, NOAA Fisheries; Department of Ecology and Evolutionary Biology, The University of California at Santa Cruz
US
Yi-Ming Gan
  • Point Of Contact
Royal Belgian Institute of Natural Sciences
BE

Geographic Coverage

South Shetland Island archipelago; Cape Shirreff, Livingston Island; San Telmo Islets

Bounding Coordinates South West [-62.47, -60.83], North East [-62, -58]

Taxonomic Coverage

All pinnipeds were identified to species level.

Species Arctocephalus gazella (Antarctic fur seal)

Temporal Coverage

Start Date / End Date 1959-01-01 / 2024-12-27

Project Data

This project contains all known total synoptic pup counts of South Shetland Antarctic fur seals in the South Shetland Islands archipelago, including specific counts from Cape Shirreff and the San Telmo Islets.

Title U.S. Antarctic Marine Living Resources Program: South Shetland Antarctic fur seal pup census
Identifier gov.noaa.nmfs.inport:72281
Funding Maintenance and continuation of this data set is funded by the NOAA Fisheries U.S. AMLR Program. Any funding information for non-AMLR counts can be found in the associated count references.

The personnel involved in the project:

Samuel M. Woodman
  • Content Provider
Douglas J. Krause
  • Principal Investigator

Sampling Methods

This dataset consists of all known, synoptic counts of South Shetland Antarctic fur seal (SSAFS) pups. Pup counts were performed by a variety of groups, and thus users should refer to the ‘samplingProtocol’ field for the sampling protocol for each count. Since 2008, all Cape Shirreff censuses have been performed by the U.S. AMLR Program, following methods described in Krause et al. (2022).

Study Extent This dataset describes all known, synoptic counts of South Shetland Antarctic fur seal (SSAFS) pups born in the South Shetland Islands archipelago, including from Cape Shirreff (62.47° S, 60.77° W) and San Telmo Islets.
Quality Control All count records were screened for unreasonable values or duplicate entries via R code, either programmatically or visually through plots of the data. Duplicates were removed, and other data flagged by automated checks were validated using paper datasheets or scans of a technician’s field notebooks. All scientific names were checked for typo and matched to the species information backbone of Worlds Register of Marine Species (http://marinespecies.org/) and LSID were assigned to each taxa as scientificNameID. Event date and time were verified to be compliant with ISO 8601 standard.

Method step description:

  1. The U.S. AMLR Program has conducted a synoptic census of SSAFS pups born at Cape Shirreff each year from 2008 to present. Annual pup censuses were done in late December (except 2021/22 which was completed in mid-December) when over 99% of pups were born, before pups explore widely beyond their birth beach, and before seasonal rates of pup predation increased. In each season at least three field biologists surveyed every breeding beach independently using hand-held binoculars. Counts of pups (live and dead) were independently reviewed, and recounts were conducted as necessary to ensure that all beach-specific counts were within 5% across all observers. Further method details may be found in Krause et al. (2022).
  2. During the 2018/19 season, the U.S. AMLR Program began conducting SSAFS censuses for the San Telmo Islets (STI) via drone, as described in Krause and Hinke (2021). Unless otherwise indicated, all subsequent STI counts were conducted in the same fashion. All previous STI counts include references describing relevant methods.
  3. The South Shetland Island archipelago-wide counts of SSAFS for 1991/92, 1995/96, 2001/02, 2007/08, and 2024/25 were conducted by the U.S. AMLR Program. References for all SSI-wide counts are included in the respective count records.
  4. All other SSAFS pup census counts were gathered via a literature review. References for these counts are included in the individual count records.

Bibliographic Citations

  1. Bengtson, J.L., Ferm, L.M., Härkönen, T.J., and Stewart,B.S. (1990). Abundance of Antarctic Fur Seals in the South Shetland Islands, Antarctica, During the 1986/87 Austral Summer. In Antarctic Ecosystems, edited by Kerry K.R. and Hempel G., 265-270. Berlin, Heidelberg: Springer.
  2. Bonin, C.A., Goebel, M.E., Forcada, J., Burton, R.S. and Hoffman, J.I. (2013). Unexpected genetic differentiation between recently recolonized populations of a long-lived and highly vagile marine mammal. Ecology and Evolution 3 (11): 3701-3712. https://doi.org/https://doi.org/10.1002/ece3.732
  3. Krause, D.J., Brownell, R.L., Jr, Bonin, C.A., Woodman, S.M., Shaftel, D. and Watters, G.M. (2024), Evaluating threats to South Shetland Antarctic fur seals amidst population collapse. Mam Rev, 54: 30-46. https://doi.org/10.1111/mam.12327
  4. Krause, D.J., Bonin, C.A., Goebel, M.E., Reiss, C.S., & Watters, G.M. (2022) The Rapid Population Collapse of a Key Marine Predator in the Northern Antarctic Peninsula Endangers Genetic Diversity and Resilience to Climate Change. Front. Mar. Sci. 8:796488. https://doi.org/10.3389/fmars.2021.796488
  5. Krause, D. J., and Hinke, J. T. (2021). Finally within reach: a drone census of an important, but practically inaccessible, Antarctic fur seal colony. Aquatic Mammals, 47(4), 349-354. https://doi.org/10.1578/AM.47.4.2021.349
  6. Paijmans, A. J., Stoffel, M.A., Bester, M.N., Cleary, A.C, De Bruyn, P.J.N., Forcada, J., Goebel, M.E., Goldsworthy, S.D., Guinet, C., Lydersen, C., Kovacs, K.M., Lowther, A., and Hoffman, J.I. (2020). The genetic legacy of extreme exploitation in a polar vertebrate. Scientific Reports 10 (1): 5089. https://doi.org/10.1038/s41598-020-61560-8
  7. Payne, MR. (1979). Growth in the Antarctic fur seal Arctocephalus gazella. Journal of Zoology 187 (1): 1-20.
  8. Thomas A. Jefferson, Marc A. Webber and Robert L. Pitman. Marine Mammals of the World: a comprehensive guide to their identification, 2nd Edition (Elsevier, 2015). https://doi.org/10.1016/C2012-0-06919-0
  9. https://www.fisheries.noaa.gov/inport/item/72281 (GUID: gov.noaa.nmfs.inport:72281)
  10. The Scientific Committee on Antarctic Research. (2023). SCAR Report 42 - September 2022 - SCAR Data Policy (2022). Zenodo. https://doi.org/10.5281/zenodo.7825314

Additional Metadata

Alternative Identifiers a02013f1-2eb2-4ecd-8f56-a455cbedce17
https://ipt-obis.gbif.us/resource?r=usamlr-ssafs-pup-census