South Shetland Antarctic fur seal pup census

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 [e-mail]. 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.

南设得兰群岛南极海狗幼崽普查数据集是设于利文斯顿岛谢里夫角的南设得兰群岛（SSI）长期监测工作的组成部分。该项工作包含对该区域内南设得兰群岛南极海狗（SSAFS）开展年度同步全面普查计数，主要由智利南极研究所（INACH）与美国国家海洋和大气管理局（NOAA）下属的美国南极海洋生物资源保护项目（U.S. AMLR）执行。该普查数据将由U.S. AMLR项目持续采集并按年度更新。

近期研究显示，南极海狗（学名：Arctocephalus gazella）至少包含4个独立亚种群（Bonin等，2013；Paijmans等，2020），其中一个亚种群在南设得兰群岛全域繁殖。该南设得兰群岛南极海狗种群是全球纬度最高的海狮科（otariids）动物种群，因此面临独特的环境与生态挑战，拥有该物种中占比极高的遗传多样性储备，并在2008至2023年间经历了种群灾难性衰退（Krause等，2023及相关参考文献）。因此，获取准确且及时更新的南设得兰群岛南极海狗种群数据，对管理者与决策者而言尤为关键。

由于繁殖季期间觅食的雌性海狗会定期离群，且雄性与亚成体的上岸模式无规律，评估海狗种群规模的最优指标为年度幼崽计数（Payne, 1979；Bengtson等，1990）。本数据集收录了1959年以来南半球夏季期间，南设得兰群岛区域内所有已知的南极海狗幼崽同步全面普查计数结果（即存活与死亡幼崽总数）。同时收录了谢里夫角（CS，若有提供则标注标准差（±SD））与圣特尔莫群岛（STI）两处核心繁殖群的计数数据。除特别标注外，所有数据均由U.S. AMLR项目采集。

多数年度普查计数均在最佳生物学窗口（12月下旬至1月上旬）开展，此时绝大多数幼崽已诞生但尚未出现大规模死亡（Krause等，2022）。项目团队确信，本数据集收录的所有计数结果具有可比性，且能够准确反映南设得兰群岛南极海狗的种群变化趋势。不过，所有记录均提供了普查日期或其最优估算值，以供有需要的研究者应用校正因子。

本数据集以标准化达尔文核心档案（Darwin Core Archive）形式发布，包含指定区域与季节内的南设得兰群岛南极海狗幼崽计数数据。本数据集采用CC0协议发布。使用本数据时，请遵循南极研究科学委员会数据政策（SCAR, 2023）的相关指南。若对本数据集存在疑问，请通过元数据中提供的联系方式或发送邮件至[e-mail]与我们取得联系。数据集相关问题可上报至https://github.com/us-amlr/ssafs-pup-census。

本数据集由美国南极海洋生物资源保护项目维护，由NOAA资助。