Machine learning identifies a strong association between warming and reduced primary productivity in an oligotrophic ocean gyre
Machine learning identifies a strong association between warming and reduced primary productivity in an oligotrophic ocean gyre
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DOI：
10.1038/s41598-020-59989-y
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发表时间：
2020-02-25
影响因子：
4.6
通讯作者：
Lomas, Michael W.
中科院分区：
文献类型：
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作者：
D'Alelio, Domenico;Rampone, Salvatore;Lomas, Michael W.
浮游植物通过调节全球海洋地球化学循环和海洋食物网的生产在海洋中发挥关键作用。全球变暖被认为通过影响浮游植物的光合代谢直接影响浮游植物的生产，并通过改变它们生长的物理环境间接影响浮游植物的生产。在这方面，在马尾藻海（北大西洋环流）进行的百慕大大西洋时间序列研究提供了一个独特的机会，可以探讨变暖对广大贫营养海洋区域浮游植物生产的影响，因为这是为数不多的几十年净初级生产力测量记录之一。我们使用机器学习技术（ML）分析了BATS站点浮游植物初级生产力的时间序列，结果表明，在27年的时间内（1990-2016年），水温升高，以及随之而来的上层海洋垂直混合的减弱，通过减少必要资源，氮和光的可用性，引起了浮游植物生产力的负反馈。随着气候变暖，这些资源的供应不平衡，再加上社区一级的生态变化，预计将加剧远离陆地营养源的公海区域的贫营养状态。
Phytoplankton play key roles in the oceans by regulating global biogeochemical cycles and production in marine food webs. Global warming is thought to affect phytoplankton production both directly, by impacting their photosynthetic metabolism, and indirectly by modifying the physical environment in which they grow. In this respect, the Bermuda Atlantic Time-series Study (BATS) in the Sargasso Sea (North Atlantic gyre) provides a unique opportunity to explore effects of warming on phytoplankton production across the vast oligotrophic ocean regions because it is one of the few multidecadal records of measured net primary productivity (NPP). We analysed the time series of phytoplankton primary productivity at BATS site using machine learning techniques (ML) to show that increased water temperature over a 27-year period (1990-2016), and the consequent weakening of vertical mixing in the upper ocean, induced a negative feedback on phytoplankton productivity by reducing the availability of essential resources, nitrogen and light. The unbalanced availability of these resources with warming, coupled with ecological changes at the community level, is expected to intensify the oligotrophic state of open-ocean regions that are far from land-based nutrient sources.