Center for Ecosystem Sentinels, Department of Biology, University of Washington, Seattle, Washington, USA.
Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, USA.
Glob Chang Biol. 2024 Sep;30(9):e17490. doi: 10.1111/gcb.17490.
Understanding how the environment mediates an organism's ability to meet basic survival requirements is a fundamental goal of ecology. Vessel noise is a global threat to marine ecosystems and is increasing in intensity and spatiotemporal extent due to growth in shipping coupled with physical changes to ocean soundscapes from ocean warming and acidification. Odontocetes rely on biosonar to forage, yet determining the consequences of vessel noise on foraging has been limited by the challenges of observing underwater foraging outcomes and measuring noise levels received by individuals. To address these challenges, we leveraged a unique acoustic and movement dataset from 25 animal-borne biologging tags temporarily attached to individuals from two populations of fish-eating killer whales (Orcinus orca) in highly transited coastal waters to (1) test for the effects of vessel noise on foraging behaviors-searching (slow-click echolocation), pursuit (buzzes), and capture and (2) investigate the mechanism of interference. For every 1 dB increase in maximum noise level, there was a 4% increase in the odds of searching for prey by both sexes, a 58% decrease in the odds of pursuit by females and a 12.5% decrease in the odds of prey capture by both sexes. Moreover, all but one deep (≥75 m) foraging attempt with noise ≥110 dB re 1 μPa (15-45 kHz band; n = 6 dives by n = 4 whales) resulted in failed prey capture. These responses are consistent with an auditory masking mechanism. Our findings demonstrate the effects of vessel noise across multiple phases of odontocete foraging, underscoring the importance of managing anthropogenic inputs into soundscapes to achieve conservation objectives for acoustically sensitive species. While the timescales for recovering depleted prey species may span decades, these findings suggest that complementary actions to reduce ocean noise in the short term offer a critical pathway for recovering odontocete foraging opportunities.
了解环境如何调节生物体满足基本生存需求的能力是生态学的一个基本目标。船只噪音是对海洋生态系统的全球性威胁，由于航运的增长以及海洋变暖酸化导致海洋声音景观的物理变化，其强度和时空范围都在增加。齿鲸依靠生物声纳觅食，但由于观察水下觅食结果和测量个体接收到的噪声水平的挑战，船只噪声对觅食的影响一直受到限制。为了解决这些挑战，我们利用了来自两个吃鱼的虎鲸（虎鲸）种群的 25 个动物携带生物标志的独特声学和运动数据集，这些标志暂时附着在高度过境沿海水域的个体上，以（1）测试船只噪声对觅食行为（搜索：慢点击回声定位）、追逐（嗡嗡声）和捕获的影响，以及（2）研究干扰的机制。最大噪声水平每增加 1dB，雌雄两性搜索猎物的几率就会增加 4%，雌性追逐猎物的几率就会降低 58%，雌雄两性捕获猎物的几率就会降低 12.5%。此外，在噪声≥110dB re 1μPa（15-45kHz 频段；n=6 次潜水，n=4 头鲸鱼）的情况下，所有但一次深度（≥75m）觅食尝试都以失败告终。这些反应与听觉掩蔽机制一致。我们的研究结果表明，船只噪声对齿鲸觅食的多个阶段都有影响，这突显了管理人为输入到声音景观中的重要性，以实现对声音敏感物种的保护目标。虽然恢复消耗殆尽的猎物物种的时间可能需要几十年，但这些发现表明，在短期内采取补充行动减少海洋噪声为恢复齿鲸觅食机会提供了一条关键途径。
