Posdaljian Natalie, Soderstjerna Caroline, Jones Joshua M, Solsona-Berga Alba, Hildebrand John A, Westdal Kristin, Ootoowak Alex, Baumann-Pickering Simone
University of California San Diego, Scripps Institution of Oceanography, La Jolla, California, USA.
Oceans North, Winnipeg, Manitoba, Canada.
Glob Chang Biol. 2022 Jun;28(12):3860-3870. doi: 10.1111/gcb.16166. Epub 2022 Apr 7.
Sperm whales (Physeter macrocephalus) are a cosmopolitan species but are only found in ice-free regions of the ocean. It is unknown how their distribution might change in regions undergoing rapid loss of sea ice and ocean warming like Baffin Bay in the eastern Canadian Arctic. In 2014 and 2018, sperm whales were sighted near Eclipse Sound, Baffin Bay: the first recorded uses of this region by sperm whales. In this study, we investigate the spatiotemporal distribution of sperm whales near Eclipse Sound using visual and acoustic data. We combine several published open-source, data sets to create a map of historical sperm whale presence in the region. We use passive acoustic data from two recording sites between 2015 and 2019 to investigate more recent presence in the region. We also analyze regional trends in sea ice concentration (SIC) dating back to 1901 and relate acoustic presence of sperm whales to the mean SIC near the recording sites. We found no records of sperm whale sightings near Eclipse Sound outside of the 2014/2018 observations. Our acoustic data told a different story, with sperm whales recorded yearly from 2015 to 2019 with presence in the late summer and fall months. Sperm whale acoustic presence increased over the 5-year study duration and was closely related to the minimum SIC each year. Sperm whales, like other cetaceans, are ecosystem sentinels, or indicators of ecosystem change. Increasing number of days with sperm whale presence in the Eclipse Sound region could indicate range expansion of sperm whales as a result of changes in sea ice. Monitoring climate change-induced range expansion in this region is important to understand how increasing presence of a top-predator might impact the Arctic food web.
抹香鲸（Physeter macrocephalus）是一种分布于世界各地的物种，但仅在无冰的海洋区域被发现。目前尚不清楚在像加拿大北极地区东部的巴芬湾这样正经历海冰快速消融和海洋变暖的区域，它们的分布会如何变化。2014年和2018年，在巴芬湾的日食海峡附近发现了抹香鲸：这是该区域首次有抹香鲸出现的记录。在本研究中，我们利用视觉和声学数据调查了日食海峡附近抹香鲸的时空分布。我们整合了多个已发表的开源数据集，以绘制该区域抹香鲸历史出现情况的地图。我们使用2015年至2019年两个记录地点的被动声学数据，来研究该区域近期抹香鲸的出现情况。我们还分析了可追溯至1901年的海冰浓度（SIC）的区域趋势，并将抹香鲸的声学出现情况与记录地点附近的平均SIC联系起来。我们在2014/2018年观测之外，未发现日食海峡附近有抹香鲸目击记录。我们的声学数据却呈现出不同的情况，2015年至2019年每年都记录到了抹香鲸，它们在夏末和秋季出现。在为期5年的研究期间，抹香鲸的声学出现次数有所增加，并且与每年的最低SIC密切相关。抹香鲸与其他鲸类一样，是生态系统的哨兵，即生态系统变化的指标。日食海峡区域抹香鲸出现天数的增加，可能表明由于海冰变化，抹香鲸的活动范围在扩大。监测该区域气候变化导致的活动范围扩大，对于理解顶级捕食者数量增加如何影响北极食物网至关重要。
