Shifts in seawater chemistry disrupt trophic links within a simple shoreline food web
Shifts in seawater chemistry disrupt trophic links within a simple shoreline food web
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DOI：
10.1007/s00442-019-04459-0
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发表时间：
2019-08-01
期刊：
影响因子：
2.7
通讯作者：
Gaylord, Brian
中科院分区：
文献类型：
--
作者：
Jellison, Brittany M.;Gaylord, Brian
长期以来，海洋潮间带系统一直是生态研究的重点环境，但由于人类产生的二氧化碳进入海水，导致“海洋酸化”（OA），这些环境正在发生变化。OA的一个组成部分是海水pH值的下降，这种变化已知会破坏生物体的捕食者-猎物相互作用行为。然而，迄今为止，研究OA的影响喂养关系主要考虑简单的直接相互作用之间的消费者和他们的食物来源。在这里，我们扩展了这些既定的方法来测试如何降低海水pH值可能会改变级联效应，跨越分层的联系在营养网络。我们采用了一个模型海岸线的食物网，将海星星捕食者（Leptasterias hexactis），草食性蜗牛猎物（Tegula funebralis），和一个共同的大型藻类资源的猎物（Mazzaella flaccida）。结果表明，直接的负面影响，低pH值的反捕食行为的蜗牛，但也削弱了间接的相互作用，驱动的大型藻类的蜗牛消费增加，即使海星吃更多的蜗牛。后一种结果的出现是因为低pH值诱导蜗牛的“鲁莽”行为，即它们的飞行反应被其他允许觅食的活动所取代。这些研究结果突出了潜在的人为引起的海水化学变化，扰乱猎物的行为和营养动力学伴随着社区一级的后果。
Marine intertidal systems have long served as focal environments for ecological research, yet these environments are changing due to the entry of human-produced carbon dioxide into seawater, which causes 'ocean acidification' (OA). One component of OA is a decline in seawater pH, an alteration known to disrupt organism behaviors underlying predator-prey interactions. To date, however, studies examining OA's effects on feeding relationships consider predominantly simple direct interactions between consumers and their food sources. Here, we extended these established approaches to test how decreased seawater pH might alter cascading effects that span tiered linkages in trophic networks. We employed a model shoreline food web incorporating a sea star predator (Leptasterias hexactis), an herbivorous snail prey (Tegula funebralis), and a common macroalgal resource for the prey (Mazzaella flaccida). Results demonstrate direct negative effects of low pH on anti-predator behavior of snails, but also weakened indirect interactions, driven by increased snail consumption of macroalgae even as sea stars ate more snails. This latter outcome arose because low pH induced 'foolhardy' behaviors in snails, whereby their flight responses were supplanted by other activities that allowed for foraging. These findings highlight the potential for human-induced changes in seawater chemistry to perturb prey behaviors and trophic dynamics with accompanying community-level consequences.