Sharp decline in humpback whale (Megaptera novaeangliae) survival and reproductive success in southeastern Alaska during and after the 2014-2016 Northeast Pacific marine heatwave
Sharp decline in humpback whale (Megaptera novaeangliae) survival and reproductive success in southeastern Alaska during and after the 2014-2016 Northeast Pacific marine heatwave
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DOI：
10.1007/s42991-021-00187-2
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发表时间：
2022-03-10
影响因子：
1.6
通讯作者：
Danielson, Seth L.
中科院分区：
文献类型：
--
作者：
Gabriele, Christine M.;Amundson, Courtney L.;Danielson, Seth L.
随着海洋热浪变得越来越普遍和严重，了解海洋变暖对生态系统的影响变得越来越重要。在这里，我们利用冰川湾国家公园的长期监测数据(1985-2020年)来调查2014-2016年东北太平洋海洋热浪(PMH)爆发后座头鲸的繁殖成功率和存活率突然急剧下降。海洋数据证实了2015-2016年冰川湾持续的暖水异常，比北太平洋记录的PMH晚了几个月。我们使用鲸鱼和幼鲸计数和多状态封闭种群捕获-重新捕获模型评估了PMH前后人口参数的变化。2013至2018年间，非犊牛丰度下降了56%，随后在2019至2020年间有所增加。女性在人口中的预测比例在2015-2017年间下降(0.40-0.44)。在热浪期间和之后的5年(2015年至2019年)，犊牛产量远远低于历史水平(每头成年母牛0.041头，而PMH前为0.27头)。从2013年(0.396-0.032)出生的小牛开始，小牛存活率下降了10倍，从2014年开始，仲夏小牛的损失以前所未有的速度发生。非小牛存活率从PMH前的0.982下降到PMH后的0.899，低于报道的该物种的任何值。我们推测，在PMH期间和之后，记录在案的饲料鱼和浮游动物猎物基地的变化是座头鲸存活率和繁殖成功减少的主要驱动因素。假设恢复到有利的饲养条件，阿拉斯加东南部的座头鲸数量和生产力可能需要数年时间才能从PMH恢复。我们的工作突显了随着气候变暖到以前没有观察到的状态，这一群体持续的脆弱性。
Understanding the ecosystem effects of ocean warming is increasingly important as marine heatwaves become more common and increase in severity. Here, we used Glacier Bay National Park long-term monitoring data (1985-2020) to investigate a sudden, sharp decline in humpback whale reproductive success and survival following the onset of the 2014-2016 Northeast Pacific marine heatwave (PMH). Oceanographic data confirm a persistent warm-water anomaly in 2015-2016 in Glacier Bay, months later than the PMH was documented in the North Pacific. We assessed changes in demographic parameters pre- and post-PMH using whale and calf counts and multi-state closed population capture-recapture models. Non-calf abundance decreased by 56% between 2013 and 2018, followed by increases in 2019-2020. The predicted proportion of females in the population declined in 2015-2017 (0.40-0.44). For 5 years during and after the heatwave (2015-2019) calf production was far lower than historic levels (0.041 calves per adult female, in contrast to 0.27 pre-PMH). Calf survival dropped tenfold beginning with calves born in 2013 (0.396-0.032) and midsummer calf losses occurred at an unprecedented rate starting in 2014. Non-calf survival declined from 0.982 pre-PMH to 0.899 post-PMH, lower than any value reported for this species. We surmise that documented changes to the forage fish and zooplankton prey base during and after the PMH were the main driver of reduced humpback whale survival and reproductive success. Humpback whale abundance and productivity in southeastern Alaska will likely take years to recover from the PMH, assuming a return to favorable feeding conditions. Our work highlights this population's continued vulnerability as the climate warms into previously unobserved states.