Mesopredator release following top predator loss may reduce biodiversity and harm foundation species. We investigated the potential for moderate environmental changes to trigger mesopredator release by disrupting the foraging ability of top predators without affecting their abundance by performing an in situ experiment designed to isolate the magnitude of mesopredator effects on oyster reefs (Crassostrea virginica). In estuaries, fishes occupy upper trophic levels. Most are visual foragers and become less effective predators in high turbidity. Communities were 10% more diverse, fish predation was 20% higher, and oyster recruitment four times higher in low turbidity. Crab mesopredators were 10% larger and 260% more abundant in high turbidity. Caging treatments to exclude mesopredators significantly affected communities in high but not low turbidity. Oysters had 150% stronger shells in turbid areas, a known response to crabs that was indicative of higher crab abundance. These findings indicated that increased turbidity attenuated fish foraging ability without disrupting the foraging ability of mesopredators (e.g., crabs) that forage by chemoreception. Larger and more numerous crab mesopredators significantly affected oyster reef community structure as well as the survival and growth of oysters in turbid environments. In environments where apex predators and mesopredators utilize different sensory mechanisms, sensory‐mediated mesopredator release may occur when conditions affect the foraging ability of higher order predators but not their prey.

中文翻译：

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多云，有中子释放的可能性：浑浊通过感觉破坏减轻中捕食者的自上而下控制

捕食者流失最多后，中度繁殖者释放可能会减少生物多样性并危害基础物种。我们通过进行原位实验来分离中等介壳虫对牡蛎礁的影响（Crassostrea virginica），从而通过破坏顶级捕食者的觅食能力而不影响其丰富度，研究了适度环境变化触发介壳虫释放的潜力）。在河口，鱼类占据较高的营养级。多数是视觉觅食者，在高浊度时掠食性降低。在低浊度中，社区的多样性提高了10％，鱼类的捕食性提高了20％，牡蛎的吸收提高了4倍。高浊度的螃蟹中指比大10％，比大260％。笼罩治疗排除中指，对高浊度社区影响很大，但并非低浊度。牡蛎在浑浊区域的壳质增强了150％，这是对螃蟹的一种已知反应，表明螃蟹的丰度更高。这些发现表明，浊度的增加减弱了鱼类的觅食能力，而不会破坏通过化学感受力觅食的中粒繁殖者（例如，螃蟹）的觅食能力。更大，数量更多的蟹类中指明显影响牡蛎礁的群落结构，以及在混浊环境中牡蛎的生存和生长。在顶点食肉动物和中食动物利用不同的感觉机制的环境中，当条件影响高阶食肉动物的觅食能力而不影响它们的猎物的觅食能力时，可能会发生由感官介导的中食动物释放。