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.

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.

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.

This dataset contains in a zipfile the shapefiles for the seabird breeding colonies at Stinker Point (Elephant Island, Maritime Antarctic Peninsula), the elevation of Stinker Point and the Elephant Island contour. All shapefiles are projected in WGS 1984 World Mercator projected coordinate system.

Since 1995 research on pinnipeds were focused on four main lines: 1. Bioenergetics In collaboration with the Mammals group from the Alfred Wegener Institute, field work is carried out on a project which aims to: (i) compare energy passed by different mothers during lactation in relation to their mass and body condition, and by the same females during different breeding seasons; (ii) assess energy gained by females during the post-breeding and post-moulting period at sea..(iii) assess energy spent by pups during fasting .

1. Population dynamics
2. Annual censuses are carried out during the breeding and moulting period in the study area.

3. A long term study of branded pups is being carried out to asses the role of year, and condition at weaning on survival.

4. Immunology Studies of serum and milk Immunoglobulin levels are carried out in cooperation with the Biochemistry Program directed by M.E.I. Marquez. The main aims of these studies are:

5. To investigate the passive transfer of immunity from mother to pup throughout the lactation period.

6. To investigate the development of active immunity in newborns of Southern elephant seals .

7. Diet The diet of different antarctic pinnipeds is investigated through stomach lavage and scat collection to assess their localities and interannual variations. Diet studies of different species of pinnipeds are conducted in collaboration with Ricardo Casaux from the Instituto Antartico Argentino and Gustavo Daneri from the Museo Argentino de Ciencias Naturales "Bernardino Rivadavia".

These data are georeferenced TIF files from an orthomosaic constructed using aerial stills imagery collected by a DJI Phantom 4 Pro. The orthomosaic is of Harmony Point on Nelson Island in the South Shetland Islands, Antarctic Peninusla, and was created using Agisoft Metashape Professional v1.6.3.

Six species of penguins breed on the Antarctic continent, the Antarctic Peninsula, the South Shetland and South Orkney Islands. Their breeding populations within the Antarctic Peninsula, and the South Orkney and South Shetland Is., and estimates of global populations are given. Typical breeding seasons are also presented, but it must be noted that these will vary inter-annually and intra-annually under the influence of factors such as sea-ice extent and ENSO (interannual) and the location of each breeding colony (southerly localities will be later than northerly localities, as their breeding season is "compressed" within the shorter summer). Their foraging strategies (categorized as near-shore or offshore) and typical durations of foraging trips are also tabulated. As with breeding season events, foraging behaviour will vary intra-seasonally and inter-seasonally (in terms of dive duration, dive depth, foraging location, etc). The distribution of known penguin breeding colonies is circum-continental, with Emperor and Adelie penguins predominant on approximately 75 % of the coast, with two major concentrations in the Ross Sea and in Prydz Bay. The third concentration is in the Antarctic Peninsula region, where some of the largest penguin colonies are present. All six species breed within the area (predominantly Chinstrap Penguins), and the Peninsula region has a greater diversity than the remainder ofthe Antarctic with respect to penguins. The distribution at sea of nonbreeding penguins is less cIear. Non-breeding individuals of all six species move throughout the Southern Ocean, and in many cases, to areas well north of the winter pack-ice zone. However, it is not possible to estimate densities of penguins at sea as there are no estimates of non-breeding penguin populations the extent of their travels.