ABSTRACT: Marine reserves are often designed to increase density, biomass, size structure, and biodiversity by prohibiting extractive activities. However, the recovery of predators following the establishment of marine reserves and the consequent cessation of fishing may have indirect negative effects on prey populations by increasing prey mortality. We coupled field surveys with empirical predation assays (i.e. tethering experiments) inside and outside of 3 no-take marine reserves in kelp forests along the central California coast to quantify the strength of interactions between predatory fishes and their crustacean prey. Results indicated elevated densities and biomass of invertebrate predators inside marine reserves compared to nearby fished sites, but no significant differences in prey densities. The increased abundance of predators inside marine reserves translated to a significant increase in mortality of 2 species of decapod crustaceans, the dock shrimp Pandalus danae and the cryptic kelp crab Pugettia richii, in tethering experiments. Shrimp mortality rates were 4.6 times greater, while crab mortality rates were 7 times greater inside reserves. For both prey species, the time to 50% mortality was negatively associated with the density and biomass of invertebrate predators (i.e. higher mortality rates where predators were more abundant). Video analyses indicated that macro-invertivore fishes arrived 2 times faster to tethering arrays at sites inside marine reserves and began attacking tethered prey more rapidly. The results indicate that marine reserves can have direct and indirect effects on predators and their prey, respectively, and highlight the importance of considering species interactions in making management decisions.

中文翻译：

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海洋保护区对加州中部海带森林中捕食者与猎物相互作用的影响

摘要：海洋保护区通常旨在通过禁止采掘活动来增加密度，生物量，大小结构和生物多样性。但是，建立海洋保护区后捕食者的恢复以及随之而来的捕捞活动可能通过增加猎物死亡率而对猎物种群产生间接的负面影响。我们将野外调查与加利福尼亚中部沿海海带森林的3个禁捕性海洋保护区内外的经验性捕食测定法（即拴系实验）结合起来，以量化掠食性鱼类与其甲壳类猎物之间相互作用的强度。结果表明与附近的捕鱼地点相比，海洋保护区内无脊椎动物掠食者的密度和生物量均增加，但猎物密度没有显着差异。系绳实验中的Pandalus danae和隐秘的海带蟹Pugettia richii。虾的死亡率高4.6倍，而蟹的死亡率高7倍。对于这两种猎物，死亡率达到50％的时间与无脊椎动物捕食者的密度和生物量呈负相关（即，在捕食者更丰富的地方死亡率更高）。录像分析表明，大型无食性鱼类到达海洋保护区内的拴系物阵列的速度快了两倍，并开始更快地攻击拴系的猎物。结果表明，海洋保护区可能分别对捕食者及其猎物产生直接和间接影响，并突出了在制定管理决策时考虑物种相互作用的重要性。