Marine and Environmental Sciences Centre (MARE), Institute of Marine Research (IMAR) and Okeanos R&D Centre, University of the Azores, Rua Frederico Machado 4, 9901-862, Horta, Portugal.
Hawaiian Islands Humpback Whale National Marine Sanctuary, National Oceanic and Atmospheric Administration (NOAA), Kihei, HI, 96753, USA.
Sci Rep. 2020 Feb 27;10(1):3610. doi: 10.1038/s41598-020-60441-4.
Several seamounts have been identified as hotspots of marine life in the Azores, acting as feeding stations for top predators, including cetaceans. Passive acoustic monitoring is an efficient tool to study temporal variations in the occurrence and behaviour of vocalizing cetacean species. We deployed bottom-moored Ecological Acoustic Recorders (EARs) to investigate the temporal patterns in acoustic presence and foraging activity of oceanic dolphins at two seamounts (Condor and Gigante) in the Azores. Data were collected in March-May 2008 and April 2010-February 2011. Dolphins were present year round and nearly every day at both seamounts. Foraging signals (buzzes and bray calls) were recorded in >87% of the days dolphin were present. There was a strong diel pattern in dolphin acoustic occurrence and behaviour, with higher detections of foraging and echolocation vocalizations during the night and of social signals during daylight hours. Acoustic data demonstrate that small dolphins consistently use Condor and Gigante seamounts to forage at night. These results suggest that these seamounts likely are important feeding areas for dolphins. This study contributes to a better understanding of the feeding ecology of oceanic dolphins and provides new insights into the role of seamount habitats for top predators.
已经确定了阿留申群岛的几座海山是海洋生物的热点地区，这些海山充当了包括鲸鱼在内的顶级捕食者的觅食站。被动声学监测是研究发声鲸鱼物种出现和行为时间变化的有效工具。我们部署了海底固定的生态声学记录仪 (EAR)，以调查阿留申群岛两座海山（Condor 和 Gigante）上海洋海豚的声学存在和觅食活动的时间模式。数据于 2008 年 3 月至 5 月和 2010 年 4 月至 2011 年 2 月期间收集。海豚全年几乎每天都在这两个海山上出现。在海豚出现的日子里，超过 87%的日子里都记录到了觅食信号（嗡嗡声和嘶嘶声）。海豚的声学出现和行为具有强烈的昼夜节律模式，夜间觅食和回声定位叫声的检测率较高，白天则是社交信号的检测率较高。声学数据表明，小海豚经常在 Condor 和 Gigante 海山夜间觅食。这些结果表明，这些海山可能是海豚的重要觅食区。这项研究有助于更好地了解海洋海豚的觅食生态学，并为深海山栖息地对顶级捕食者的作用提供了新的见解。
