ABSTRACT: Sea otters Enhydra lutris have been absent from Oregon, USA, following their extirpation over a century ago. Stakeholder groups and native tribes are advocating for reintroduction to restore historic populations. We investigated the potential for successful reintroduction by: (1) estimating expected equilibrium sea otter densities as a function of habitat variables to assess sea otter habitat in Oregon; and (2) spatially relating areas of high expected densities to human activities (e.g. fisheries, recreation, vessel activity, protected areas) to anticipate potential disturbance or fishery resource competition. We estimated that 4538 (1742-8976; 95% CI) sea otters could exist in Oregon, with higher expected abundance (N = 1551) and densities (x̄ = 2.45 km^-2) within the southern region. Most core habitat areas (97%), representing clusters of high expected densities, overlapped with some form of human activity. While commercial shipping and tow lanes overlapped little (1%) with core habitat areas, recreational activities (58%) and fisheries (76%) had a higher degree of overlap, posing higher disturbance risk. We anticipate higher resource competition potential with the commercial red sea urchin fishery (67% of harvest areas) than the commercial Dungeness crab fishery (9% of high-catch crabbing grounds). Our study presents the first published carrying capacity estimate for sea otters in Oregon and can provide population recovery targets, focus attention on ecological and socioeconomic considerations, and help to inform a recovery plan for a resident sea otter population. Our findings suggest current available habitat may be sufficient to support a sea otter population, but resource managers may need to further investigate and consider whether current human activities might conflict with reestablishment in Oregon, if plans for a reintroduction continue.

中文翻译：

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通过栖息地和人类互动评估为重新引入水獭提供信息

摘要：海獭的Enhydra lutris一直缺席美国俄勒冈州，跟随他们摘除了一个多世纪以前。利益相关者团体和当地部落提倡重新引入以恢复历史人口。我们通过以下方法研究了成功再引入的潜力：（1）估算预期的平衡水獭密度与栖息地变量的函数，以评估俄勒冈州的水獭栖息地；（2）在空间上将高预期密度的区域与人类活动（例如渔业，娱乐，船只活动，保护区）相关联，以预测潜在的干扰或渔业资源竞争。我们估计俄勒冈州可能存在4538（1742-8976; 95％CI）海獭，其预期丰度（N = 1551）和密度（x̄ = 2.45 km ^-2）在南部地区。大多数核心栖息地区域（97％）代表着高预期密度的集群，与某种形式的人类活动重叠。商业运输和拖行道与核心栖息地几乎没有重叠（1％），而娱乐活动（58％）和渔业（76％）的重叠程度更高，带来更高的干扰风险。我们预计商业红海胆渔业（占收获面积的67％）比商业大吉蟹捕捞（高捕捞蟹场的9％）具有更高的资源竞争潜力。我们的研究提出了俄勒冈州首次发布的水獭承载力估计，可以提供人口恢复目标，将注意力集中在生态和社会经济因素上，并有助于为常住水獭人口制定恢复计划。