Carroll Gemma, Everett Jason D, Harcourt Robert, Slip David, Jonsen Ian
Department of Biological Sciences, Faculty of Science and Engineering, Macquarie University, Sydney NSW 2109, Australia.
Evolution &Ecology Research Centre, School of Biological Earth and Environmental Sciences, University of New South Wales, Sydney NSW 2052, Australia.
Sci Rep. 2016 Feb 29;6:22236. doi: 10.1038/srep22236.
The world's oceans are undergoing rapid, regionally specific warming. Strengthening western boundary currents play a role in this phenomenon, with sea surface temperatures (SST) in their paths rising faster than the global average. To understand how dynamic oceanography influences food availability in these ocean warming "hotspots", we use a novel prey capture signature derived from accelerometry to understand how the warm East Australian Current shapes foraging success by a meso-predator, the little penguin. This seabird feeds on low trophic level species that are sensitive to environmental change. We found that in 2012, prey capture success by penguins was high when SST was low relative to the long-term mean. In 2013 prey capture success was low, coincident with an unusually strong penetration of warm water. Overall there was an optimal temperature range for prey capture around 19-21 °C, with lower success at both lower and higher temperatures, mirroring published relationships between commercial sardine catch and SST. Spatially, higher SSTs corresponded to a lower probability of penguins using an area, and lower prey capture success. These links between high SST and reduced prey capture success by penguins suggest negative implications for future resource availability in a system dominated by a strengthening western boundary current.
全球海洋正在经历快速的、区域特定的变暖。增强的西边界流在这一现象中发挥了作用，其路径上的海面温度（SST）上升速度快于全球平均水平。为了了解动态海洋学如何影响这些海洋变暖“热点”地区的食物供应，我们使用一种源自加速度测量的新颖猎物捕获特征，来了解温暖的东澳大利亚洋流如何塑造中捕食者小企鹅的觅食成功率。这种海鸟以对环境变化敏感的低营养级物种为食。我们发现，2012年，当海面温度相对于长期平均值较低时，企鹅的猎物捕获成功率较高。2013年，猎物捕获成功率较低，同时暖水出现异常强烈的渗透。总体而言，猎物捕获的最佳温度范围在19 - 21°C左右，在较低和较高温度下成功率均较低，这与已发表的商业沙丁鱼捕捞量与海面温度之间的关系相符。在空间上，较高的海面温度对应着企鹅使用某一区域的概率较低，以及猎物捕获成功率较低。高海面温度与企鹅猎物捕获成功率降低之间的这些联系，表明在一个以西边界流增强为主导的系统中，未来资源可用性将受到负面影响。
