Orca Behavior Institute, Friday Harbor, WA, United States of America.
PeerJ. 2023 Jul 12;11:e15635. doi: 10.7717/peerj.15635. eCollection 2023.
The fish-eating Southern Resident killer whales () of the northeastern Pacific are listed as Endangered in both the USA and Canada. The inland waters of Washington State and British Columbia, a region known as the Salish Sea, are designated as Southern Resident critical habitat by both countries. The whales have historically had regular monthly presence in the Salish Sea, with peak abundance occurring from May through September. In recent years, at least partially in response to shifting prey abundance, habitat usage by the Southern Residents has changed. As conservation measures aim to provide the best possible protection for the whales in their hopeful recovery, it is key that policies are based both on historic trends and current data. To this aim, our study shares 2018-2022 daily occurrence data to build upon and compare to previously published whale presence numbers and to demonstrate more recent habitat shifts. Based on reports from an extensive network of community scientists as well as online streaming hydrophones, every Southern Resident occurrence was confirmed either visually or acoustically. Documented here are the first-ever total absence of the Southern Residents in the Salish Sea in the months of May, June, and August, as well as their continued overall declining presence in the spring and summer, while fall and winter presence remains relatively high. It is key that management efforts consider these shifting presence patterns when setting both seasonal and regional protection measures aimed at supporting population recovery.
东北太平洋的食鱼型南方居留鲸()在美加两国均被列为濒危物种。华盛顿州和不列颠哥伦比亚省的内陆水域,即被称为萨利希海的地区,两国均将其指定为南方居留鲸的关键栖息地。这些鲸鱼历史上每月都会定期出现在萨利希海,其数量峰值出现在 5 月至 9 月。近年来,部分原因是由于猎物丰度的变化,南方居民的栖息地使用情况发生了变化。由于保护措施旨在为鲸鱼的恢复提供尽可能好的保护,因此政策的制定既要基于历史趋势,又要基于当前数据。为此,我们的研究分享了 2018-2022 年的每日出现数据,以建立并与之前发表的鲸鱼存在数量进行比较,并展示最近的栖息地变化。根据社区科学家广泛网络的报告以及在线流媒体水听器,每一次南方居民的出现都通过视觉或声学得到了确认。本文首次记录了南方居民在 5 月、6 月和 8 月完全没有出现在萨利希海,以及它们在春季和夏季的整体存在持续下降,而秋季和冬季的存在仍然相对较高。在制定旨在支持种群恢复的季节性和区域性保护措施时,管理工作必须考虑到这些存在模式的变化。