Otaria flavescens has been one of the most heavily exploited pinnipeds during the last 200 years, with depletion of ~90% in some colonies. After the prohibition on sealing in South America, populations stabilized except for the Uruguayan population, which showed a constant decrease. The underlying causes of its decline are unknown. This study used genome-wide single nucleotide polymorphisms to assess the variability and connectivity of some of the most overexploited sea lion colonies in the Atlantic Ocean. Our results revealed low allelic richness, nucleotide diversity, and heterozygosity in the Uruguayan population and evidence of complete isolation from the Argentinean populations under study. In contrast, the Patagonian populations showed a high degree of connectivity, which could explain their recovery and high levels of diversity at present. Our study highlights the critical situation of the Uruguayan sea lion population, emphasizing the need for maintaining continuous conservation efforts in the region.

中文翻译：

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全基因组单核苷酸多态性揭示了收获后南美鳍足类种群的低遗传变异性和高隔离性

过去 200 年来，苦参一直是遭受最严重开发的鳍足类动物之一，在一些栖息地，其数量已减少约 90%。南美洲禁止海豹捕猎后，除乌拉圭种群数量持续减少外，其他种群数量趋于稳定。其衰落的根本原因尚不清楚。这项研究利用全基因组单核苷酸多态性来评估大西洋一些最过度开发的海狮群体的变异性和连通性。我们的结果揭示了乌拉圭人群的等位基因丰富度、核苷酸多样性和杂合性较低，以及与所研究的阿根廷人群完全分离的证据。相比之下，巴塔哥尼亚种群表现出高度的连通性，这可以解释它们目前的恢复和高水平的多样性。我们的研究强调了乌拉圭海狮种群的危急状况，强调了在该地区保持持续保护工作的必要性。