Cartwright R, Venema A, Hernandez V, Wyels C, Cesere J, Cesere D
The Keiki Kohola Project, Kihei, HI 96753, USA.
Department of Environmental Science and Resource Management, California State University Channel Islands, One University Drive, Camarillo, CA 93012, USA.
R Soc Open Sci. 2019 Mar 20;6(3):181463. doi: 10.1098/rsos.181463. eCollection 2019 Mar.
Alongside changing ocean temperatures and ocean chemistry, anthropogenic climate change is now impacting the fundamental processes that support marine systems. However, where natural climate aberrations mask or amplify the impacts of anthropogenic climate change, identifying key detrimental changes is challenging. In these situations, long-term, systematic field studies allow the consequences of anthropogenically driven climate change to be distinguished from the expected fluctuations in natural resources. In this study, we describe fluctuations in encounter rates for humpback whales, , between 2008 and 2018. Encounter rates were assessed during transect surveys of the Au'Au Channel, Maui, Hawaii. Initially, rates increased, tracking projected growth rates for this population segment. Rates reached a peak in 2013, then declined through 2018. Specifically, between 2013 and 2018, mother-calf encounter rates dropped by 76.5%, suggesting a rapid reduction in the reproductive rate of the newly designated Hawaii Distinct Population Segment of humpback whales during this time. As this decline coincided with changes in the Pacific decadal oscillation, the development of the NE Pacific marine heat wave and the evolution of the 2016 El Niño, this may be another example of the impact of this potent trifecta of climatic events within the North Pacific.
除了海洋温度和海洋化学性质的变化外，人为气候变化现在正在影响支持海洋系统的基本过程。然而，在自然气候异常掩盖或放大人为气候变化影响的情况下，识别关键的有害变化具有挑战性。在这些情况下，长期、系统的实地研究可以将人为驱动的气候变化的后果与自然资源的预期波动区分开来。在本研究中，我们描述了2008年至2018年间座头鲸相遇率的波动情况。相遇率是在夏威夷毛伊岛奥奥海峡的断面调查中评估的。最初，相遇率上升，追踪该种群的预计增长率。2013年达到峰值，然后在2018年之前下降。具体而言，2013年至2018年间，母鲸与幼鲸的相遇率下降了76.5%，这表明在此期间新划定的夏威夷座头鲸独特种群的繁殖率迅速下降。由于这种下降与太平洋年代际振荡的变化、东北太平洋海洋热浪的发展以及2016年厄尔尼诺现象的演变同时发生，这可能是北太平洋这一强大的三重气候事件影响的又一个例子。
