Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California, United States of America.
PLoS One. 2012;7(3):e32390. doi: 10.1371/journal.pone.0032390. Epub 2012 Mar 5.
Efforts to restore top predators in human-altered systems raise the question of whether rebounds in predator populations are sufficient to restore pristine foodweb dynamics. Ocean ecosystems provide an ideal system to test this question. Removal of fishing in marine reserves often reverses declines in predator densities and size. However, whether this leads to restoration of key functional characteristics of foodwebs, especially prey foraging behavior, is unclear. The question of whether restored and pristine foodwebs function similarly is nonetheless critically important for management and restoration efforts. We explored this question in light of one important determinant of ecosystem function and structure--herbivorous prey foraging behavior. We compared these responses for two functionally distinct herbivorous prey fishes (the damselfish Plectroglyphidodon dickii and the parrotfish Chlorurus sordidus) within pairs of coral reefs in pristine and restored ecosystems in two regions of these species' biogeographic ranges, allowing us to quantify the magnitude and temporal scale of this key ecosystem variable's recovery. We demonstrate that restoration of top predator abundances also restored prey foraging excursion behaviors to a condition closely resembling those of a pristine ecosystem. Increased understanding of behavioral aspects of ecosystem change will greatly improve our ability to predict the cascading consequences of conservation tools aimed at ecological restoration, such as marine reserves.
努力恢复人类改变的系统中的顶级捕食者提出了这样一个问题，即捕食者种群的反弹是否足以恢复原始的食物网动态。海洋生态系统为检验这一问题提供了一个理想的系统。海洋保护区内捕鱼的减少通常会扭转捕食者密度和体型的下降。然而，这是否会导致食物网的关键功能特征得到恢复，特别是猎物的觅食行为，尚不清楚。恢复的和原始的食物网是否具有相似的功能，这对于管理和恢复工作来说是至关重要的。鉴于生态系统功能和结构的一个重要决定因素——草食性猎物的觅食行为，我们探讨了这个问题。我们比较了这两个功能上不同的草食性猎物鱼类（雀鲷属的 Plectroglyphidodon dickii 和鹦嘴鱼属的 Chlorurus sordidus）在两个物种生物地理范围的两个区域的原始和恢复生态系统中的珊瑚礁对的响应，从而可以量化这个关键生态变量恢复的幅度和时间尺度。我们证明，顶级捕食者数量的恢复也使猎物觅食游移行为恢复到与原始生态系统非常相似的状态。对生态系统变化的行为方面的理解的提高，将极大地提高我们预测旨在进行生态恢复的保护工具（如海洋保护区）的级联后果的能力。
