Bahlburg Dominik, Menze Sebastian, Krafft Bjørn A, Lowther Andy D, Meyer Bettina
Polar Biological Oceanography, Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven 27570, Germany.
Helmholtz Institute for Functional Marine Biodiversity, Oldenburg 26129, Germany.
Proc Natl Acad Sci U S A. 2025 Jun 24;122(25):e2417203122. doi: 10.1073/pnas.2417203122. Epub 2025 Jun 16.
Antarctic krill is a keystone species in the Antarctic marine ecosystem and the target of a growing fishery. Given the ecological importance of krill, concerns have been raised about potential negative impacts of fishing on the Southern Ocean ecosystem. Resource-efficient approaches to fisheries monitoring are particularly valuable in this context due to the high costs associated with data collection in Antarctica. In this study, we trained a segmentation model (U-Net) to extract dives of air-breathing krill predators from more than 30,000 h of active acoustic data collected by three krill fishing vessels over six years. We were able to characterize the temporal and spatial dynamics of predator-vessel co-occurrences, which aligned well with the findings from more costly tracking studies. For example, we found that encounters with whales consistently peaked in autumn around the Antarctic Peninsula, when whales are building up fat reserves for their migration to breeding grounds. We also demonstrated that protection measures, introduced to protect breeding penguins at the Antarctic Peninsula, have simply shifted penguin-vessel encounters to the South Orkney Islands, where the affected colonies are not currently monitored. Our approach, results, and application example demonstrate how acoustic data from fishing vessels can provide important information to support fisheries management. As a by-product of fishing operations, these data are cost-effective, offering unique temporal and spatial coverage and providing a useful basis for rapid, low-level assessments of the fishery's interaction with the wider ecosystem. This is particularly important given the unpredictable dynamics of krill fishery management decision-making.
南极磷虾是南极海洋生态系统中的关键物种，也是日益增长的渔业捕捞目标。鉴于磷虾的生态重要性，人们对捕捞活动可能对南大洋生态系统产生的负面影响表示担忧。在这种情况下，由于在南极洲收集数据成本高昂，资源高效的渔业监测方法尤为重要。在本研究中，我们训练了一个分割模型（U-Net），从三艘磷虾捕捞船在六年内收集的超过30000小时的有源声学数据中提取呼吸空气的磷虾捕食者的潜水情况。我们能够描述捕食者与船只同时出现的时间和空间动态，这与成本更高的跟踪研究结果高度吻合。例如，我们发现，在南极半岛附近，与鲸鱼的相遇在秋季始终达到峰值，此时鲸鱼正在为迁徙到繁殖地储备脂肪。我们还证明，为保护南极半岛繁殖企鹅而采取的保护措施，只是将企鹅与船只的相遇转移到了南奥克尼群岛，而目前并未对受影响的企鹅群落进行监测。我们的方法、结果和应用实例表明，捕捞船的声学数据如何能够提供重要信息以支持渔业管理。作为捕捞作业的副产品，这些数据具有成本效益，提供了独特的时间和空间覆盖范围，并为快速、低层次评估渔业与更广泛生态系统的相互作用提供了有用的基础。鉴于磷虾渔业管理决策的不可预测动态，这一点尤为重要。
