Department of Applied Math and Statistics, Center for Stock Assessment Research, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA, 95060, USA.
Farallon Institute, 101H Street, Suite Q, Petaluma, CA, 94952, USA.
Sci Rep. 2018 May 15;8(1):7579. doi: 10.1038/s41598-018-25742-9.
Submarine canyon systems are ubiquitous features of marine ecosystems, known to support high levels of biodiversity. Canyons may be important to benthic-pelagic ecosystem coupling, but their role in concentrating plankton and structuring pelagic communities is not well known. We hypothesize that at the scale of a large marine ecosystem, canyons provide a critical habitat network, which maintain energy flow and trophic interactions. We evaluate canyon characteristics relative to the distribution and abundance of krill, critically important prey in the California Current Ecosystem. Using a geological database, we conducted a census of canyon locations, evaluated their dimensions, and quantified functional relationships with krill hotspots (i.e., sites of persistently elevated abundance) derived from hydro-acoustic surveys. We found that 76% of krill hotspots occurred within and adjacent to canyons. Most krill hotspots were associated with large shelf-incising canyons. Krill hotspots and canyon dimensions displayed similar coherence as a function of latitude and indicate a potential regional habitat network. The latitudinal migration of many fish, seabirds and mammals may be enhanced by using this canyon-krill network to maintain foraging opportunities. Biogeographic assessments and predictions of krill and krill-predator distributions under climate change may be improved by accounting for canyons in habitat models.
海底峡谷系统是海洋生态系统中普遍存在的特征，已知它们支持着高度的生物多样性。峡谷可能对底栖-浮游生态系统的耦合很重要，但它们在聚集浮游生物和构建浮游生物群落方面的作用还不是很清楚。我们假设，在大型海洋生态系统的范围内，峡谷提供了一个关键的栖息地网络，维持着能量流动和营养相互作用。我们评估了峡谷的特征与磷虾的分布和丰度的关系，磷虾是加利福尼亚海流生态系统中至关重要的猎物。我们利用地质数据库对峡谷的位置进行了普查，评估了它们的尺寸，并从水声学调查中确定了与磷虾热点（即持续高丰度的地点）的功能关系。我们发现，76%的磷虾热点发生在峡谷内和峡谷附近。大多数磷虾热点都与大型陆架切入峡谷有关。磷虾热点和峡谷的尺寸与纬度呈相似的相关性，表明存在一个潜在的区域栖息地网络。许多鱼类、海鸟和哺乳动物的纬度迁移可能会通过利用这个峡谷-磷虾网络来维持觅食机会而得到增强。在生物地理评估和预测磷虾和磷虾捕食者在气候变化下的分布时，考虑到栖息地模型中的峡谷，可能会提高预测的准确性。
