Sea otters, Enhydra lutris, were once abundant along the nearshore areas of the North Pacific. The international maritime fur trade that ended in 1911 left 13 small remnant populations with low genetic diversity. Subsequent translocations into previously occupied habitat resulted in several reintroduced populations along the coast of North America. We sampled sea otters between 2008 and 2011 throughout much of their current range and used 19 nuclear microsatellite markers to evaluate genetic diversity, population structure, and connectivity between remnant and reintroduced populations. Average genetic diversity within populations was similar: observed heterozygosity 0.55 and 0.53, expected heterozygosity 0.56 and 0.52, unbiased expected heterozygosity 0.57 and 0.52, for reintroduced and remnant populations, respectively. Sea otter population structure was greatest between the Northern and Southern sea otters with further structuring in Northern sea otters into Western, Central, and Southeast populations (including the reintroduced populations). Migrant analyses suggest the successful reintroductions and growth of remnant groups have enhanced connectivity and gene flow between populations throughout many of the sampled Northern populations. We recommend that future management actions for the Southern sea otter focus on future reintroductions to fill the gap between the California and Washington populations ultimately restoring gene flow to the isolated California population.

中文翻译：

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易位保持遗传多样性并增加海獭的连通性，Enhydra lutris

海獭，Enhydra lutris，曾经在北太平洋的近岸地区丰富。1911 年结束的国际海上毛皮贸易留下了 13 个遗传多样性低的小型残余种群。随后易位到以前居住的栖息地导致沿北美海岸重新引入了几个种群。我们在 2008 年至 2011 年期间对海獭目前的大部分范围进行了采样，并使用 19 个核微卫星标记来评估遗传多样性、种群结构以及残余种群和重新引入种群之间的连通性。种群内的平均遗传多样性相似：观察到的杂合度分别为 0.55 和 0.53，预期杂合度为 0.56 和 0.52，无偏预期杂合度分别为 0.57 和 0.52，分别用于重新引入和剩余种群。海獭种群结构在北部和南部海獭之间最大，北部海獭进一步结构化为西部、中部和东南部种群（包括重新引入的种群）。移民分析表明，残余群体的成功重新引入和增长增强了许多北方采样种群的种群之间的连通性和基因流动。我们建议未来南方海獭的管理行动将重点放在未来的重新引入上，以填补加利福尼亚和华盛顿种群之间的差距，最终恢复向孤立的加利福尼亚种群的基因流动。移民分析表明，残余群体的成功重新引入和增长增强了许多北方采样种群的种群之间的连通性和基因流动。我们建议未来南方海獭的管理行动将重点放在未来的重新引入上，以填补加利福尼亚和华盛顿种群之间的差距，最终恢复向孤立的加利福尼亚种群的基因流动。移民分析表明，残余群体的成功重新引入和增长增强了许多北方采样种群的种群之间的连通性和基因流动。我们建议未来南方海獭的管理行动将重点放在未来的重新引入上，以填补加利福尼亚和华盛顿种群之间的差距，最终恢复向孤立的加利福尼亚种群的基因流动。