Fishing Indirectly Structures Macroalgal Assemblages by Altering Herbivore Behavior
Fishing Indirectly Structures Macroalgal Assemblages by Altering Herbivore Behavior
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DOI：
10.1086/657039
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发表时间：
2010-12-01
影响因子：
2.9
通讯作者：
Warner, Robert R.
中科院分区：
文献类型：
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作者：
Madin, Elizabeth M. P.;Gaines, Steven D.;Warner, Robert R.
捕鱼对被捕捞的物种有明显的直接影响，但其级联的间接影响却不太清楚。捕鱼不成比例地将大型掠食性鱼类从海洋食物网中剔除。大多数研究的间接影响集中在密度介导的相互作用，捕食者的去除交替驱动增加和减少的丰度依次较低的营养级物种。虽然猎物的数量可能会随着捕食者的减少而增加，但它们也可能会改变自己的行为。当这种行为反应影响猎物物种的食物资源时，行为介导的营养级联可以显著地塑造景观。目前尚不清楚这种变化途径是否通常由海洋捕捞引发。通过将一个简单的觅食模型与珊瑚礁的经验观察相结合，我们提供了一个机械的基础来理解和预测捕食者的收获如何改变食草动物的风险景观，从而推动初级生产者分布的巨大变化。这些结果扩大了渔业的营养级联预测，包括行为变化。他们还提供了一个框架，用于检测行为介导的级联反应的存在和规模。这方面的知识将有助于调和预期的和观察到的捕鱼引起的海洋级联模式之间的差异。
Fishing has clear direct effects on harvested species, but its cascading, indirect effects are less well understood. Fishing disproportionately removes larger, predatory fishes from marine food webs. Most studies of the consequent indirect effects focus on density-mediated interactions where predator removal alternately drives increases and decreases in abundances of successively lower trophic-level species. While prey may increase in number with fewer predators, they may also alter their behavior. When such behavioral responses impact the food resources of prey species, behaviorally mediated trophic cascades can dramatically shape landscapes. It remains unclear whether this pathway of change is typically triggered by ocean fishing. By coupling a simple foraging model with empirical observations from coral reefs, we provide a mechanistic basis for understanding and predicting how predator harvest can alter the landscape of risk for herbivores and consequently drive dramatic changes in primary producer distributions. These results broaden trophic cascade predictions for fisheries to include behavioral changes. They also provide a framework for detecting the presence and magnitude of behaviorally mediated cascades. This knowledge will help to reconcile the disparity between expected and observed patterns of fishing-induced cascades in the sea.