Biology Department, Dalhousie University, Halifax, Nova Scotia, Canada.
School of Biological Sciences, University of Western Australia, Perth, Australia.
PLoS One. 2020 May 14;15(5):e0232628. doi: 10.1371/journal.pone.0232628. eCollection 2020.
Leatherback sea turtles (Dermochelys coriacea) migrate to temperate Canadian Atlantic waters to feed on gelatinous zooplankton ('jellyfish') every summer. However, the spatio-temporal connection between predator foraging and prey-field dynamics has not been studied at the large scales over which these migratory animals occur. We use 8903 tows of groundfish survey jellyfish bycatch data between 2006-2017 to reveal spatial jellyfish hot spots, and matched these data to satellite-telemetry leatherback data over time and space. We found highly significant overlap of jellyfish and leatherback distribution on the Scotian Shelf (r = 0.89), moderately strong correlations of jellyfish and leatherback spatial hot spots in the Gulf of St. Lawrence (r = 0.59), and strong correlations in the Bay of Fundy (r = 0.74), which supports much lower jellyfish density. Over time, jellyfish bycatch data revealed a slight northward range shift in the Gulf of St. Lawrence, consistent with gradual warming of these waters. Two-stage generalized linear modelling corroborated that sea surface temperature, year, and region were significant predictors of jellyfish biomass, suggesting a climate signal on jellyfish distribution, which may shift leatherback critical feeding habitat over time. These findings are useful in predicting dynamic habitat use for endangered leatherback turtles, and can help to anticipate large-scale changes in their distribution in response to climate-related changes in prey availability.
棱皮龟（Dermochelys coriacea）每年夏天都会迁徙到加拿大大西洋的温带水域，以摄食凝胶状浮游动物（“水母”）。然而，在这些迁徙动物活动的大范围内，捕食者觅食和猎物场动态之间的时空联系尚未得到研究。我们使用 2006-2017 年间进行的 8903 次底层鱼类调查中的水母兼捕数据，揭示了空间上的水母热点，并将这些数据与随时间和空间匹配的卫星遥测棱皮龟数据进行匹配。我们发现，在斯科舍浅滩（r = 0.89）上，水母和棱皮龟的分布高度重叠；在圣劳伦斯湾（r = 0.59），水母和棱皮龟的空间热点之间存在中度强相关性；在芬迪湾（r = 0.74），相关性很强，而那里的水母密度则较低。随着时间的推移，水母兼捕数据显示，圣劳伦斯湾的范围略有向北移动，这与这些水域的逐渐变暖相一致。两阶段广义线性模型证实，海表温度、年份和区域是水母生物量的重要预测因子，这表明了气候对水母分布的影响，这可能会随着时间的推移改变棱皮龟关键的觅食栖息地。这些发现有助于预测濒危棱皮龟的动态栖息地利用，并有助于预测它们的分布在未来因猎物可用性与气候相关变化而发生的大规模变化。
