Species recovery and recolonization of past habitats: lessons for science and conservation from sea otters in estuaries
Species recovery and recolonization of past habitats: lessons for science and conservation from sea otters in estuaries
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过去栖息地的物种恢复和重新殖民：河口海獭的科学和保护教训
作者：
Brent B. Hughes;K. Wasson;M. Tinker;Susan L. Williams;Lilian P. Carswell;K. Boyer;M. Beck;R. Eby;R. Scoles;M. Staedler;Sarah Espinosa;M. Hessing‐Lewis;Erin U Foster;Kathryn M. Beheshti;Tracy M Grimes;B. H. Becker;L. Needles;Joseph A. Tomoleoni;Jane Rudebusch;Ellen M. Hines;B. Silliman
恢复中的物种通常被限制在比它们历史上占据的区域小得多的区域。对正在恢复的物种的保护规划通常基于这个有限的范围，这可能只是幸存种群持续存在的地方的人工制品。南方海獭(Enhya Lutris Nereis)被猎杀到几乎灭绝，但在加利福尼亚州外海岸偏远地带的一小部分残存种群中恢复了过来，它们的大部分恢复都发生在那里。然而，对最近重新定居的河口的研究表明，河口可以为南部海獭提供高质量的栖息地，具有浅水、高产和充足的食物、有限的捕食者和受保护的捕捞机会。此外，海獭可以对河口生态系统产生强烈影响，通过捕食无脊椎动物猎物来培养海草的适应能力。利用文献综述、种群模型和猎物调查相结合的方法，我们探索了当前南部海獭范围外的以前的河口栖息地，以确定这些河口栖息地是否能够支持健康的海獭种群。我们发现，大多数研究和保护工作都集中在暴露的、多岩石的沿海栖息地的种群。然而，历史证据表明，海獭以前也无处不在地出现在河口。我们为加州最大的河口-旧金山湾-建立的特定栖息地的种群增长模型确定，仅旧金山湾就可以养活大约6600只海獭，是2018年加州种群数量的两倍多。对目前有(Elkhorn Slough和Morro Bay)和没有(San Francisco Bay和Drakes Estero)海獭的河口进行的猎物调查表明，猎物的可获得性，特别是螃蟹，足以支持健康的海獭种群。结合历史证据和我们的结果，我们表明，保护从业者可以考虑将以前的河口栖息地作为海獭和生态系统恢复的目标。这项研究揭示了了解恢复物种如何与它们历史上占据的所有生态系统相互作用的重要性，这对于改善恢复物种的保护和成功恢复生态系统功能和过程都具有重要意义。
Recovering species are often limited to much smaller areas than they historically occupied. Conservation planning for the recovering species is often based on this limited range, which may simply be an artifact of where the surviving population persisted. Southern sea otters (Enhydra lutris nereis) were hunted nearly to extinction but recovered from a small remnant population on a remote stretch of the California outer coast, where most of their recovery has occurred. However, studies of recently-recolonized estuaries have revealed that estuaries can provide southern sea otters with high quality habitats featuring shallow waters, high production and ample food, limited predators, and protected haul-out opportunities. Moreover, sea otters can have strong effects on estuarine ecosystems, fostering seagrass resilience through their consumption of invertebrate prey. Using a combination of literature reviews, population modeling, and prey surveys we explored the former estuarine habitats outside the current southern sea otter range to determine if these estuarine habitats can support healthy sea otter populations. We found the majority of studies and conservation efforts have focused on populations in exposed, rocky coastal habitats. Yet historical evidence indicates that sea otters were also formerly ubiquitous in estuaries. Our habitat-specific population growth model for California’s largest estuary—San Francisco Bay—determined that it alone can support about 6,600 sea otters, more than double the 2018 California population. Prey surveys in estuaries currently with (Elkhorn Slough and Morro Bay) and without (San Francisco Bay and Drakes Estero) sea otters indicated that the availability of prey, especially crabs, is sufficient to support healthy sea otter populations. Combining historical evidence with our results, we show that conservation practitioners could consider former estuarine habitats as targets for sea otter and ecosystem restoration. This study reveals the importance of understanding how recovering species interact with all the ecosystems they historically occupied, both for improved conservation of the recovering species and for successful restoration of ecosystem functions and processes.
影响因子：
5.9
作者：
K. Wasson;R. Jeppesen;C. Endris;Danielle C. Perry;A. Woolfolk;Kathryn M. Beheshti;M. Rodríguez;R. Eby;E. Watson;F. Rahman;J. Haskins;Brent B. Hughes
通讯作者：
K. Wasson;R. Jeppesen;C. Endris;Danielle C. Perry;A. Woolfolk;Kathryn M. Beheshti;M. Rodríguez;R. Eby;E. Watson;F. Rahman;J. Haskins;Brent B. Hughes