Trait mediated interactions in sedimentary shorelines

尽管海洋沉积底部占据了海洋领域的绝大部分，但我们对形成其生物多样性的过程的理解仍然是零碎的。大多数理论预测，在非结构化的海洋沉积物中，捕食在调节群落结构方面起着至关重要的作用。事实上，许多开创性的研究已经证明，在局部尺度上，捕食者有能力调节猎物种群和群落的动态。然而，捕食者的作用不仅仅是捕食者消耗猎物的结果。非消耗效应，即捕食者改变了中等水平捕食者的特征，也可能在不改变捕食者密度的情况下影响猎物的数量和群落。来自岩石海岸和其他已知栖息地的越来越多的证据表明，这些间接影响，通常被称为“性状介导的间接相互作用”，可能至少与消费效应一样重要。不幸的是，在沉积底部等栖息地，性状介导的相互作用没有得到与消耗效应相同的重视。中级消费者特征的改变，例如其行为模式或摄食率，可能会对较低营养水平产生连锁反应，因此应该仔细检查。我建议通过利用大西洋地区存在的一系列物种和栖息地来评估沉积底部特征介导的间接相互作用。本项目旨在测试与三个平行研究场景相关的一系列假设：评估海洋沉积物中性状与密度介导的相互作用，性状介导的相互作用在多种捕食者共存中的作用，以及研究掠食性入侵者中性状介导的相互作用。在与海洋沉积物相关的分散生物栖息地（牡蛎、贻贝和鳗草床）中已经进行了大量的勘探工作，为本提案中提出的研究问题提供了基础。考虑到它们的范围，该计划的结果有望为沿海沉积物和其他海洋栖息地中物种相互作用的理论做出贡献。

Although marine sedimentary bottoms encompass a vast majority of the marine realm, our understanding of the processes that shape their biodiversity remains fragmentary. Most theory predicts that in unstructured marine sediments predation plays a paramount role regulating community structure. Indeed, numerous seminal studies have demonstrated that at the local scale, predators have the ability to regulate the dynamics of prey populations and communities. The role of predation, however, is not only the result of predator consumption of prey. Non-consumptive effects, where a predator modifies a trait of a mid-level consumer may also affect prey populations and communities without modifying the consumer’s density. Mounting evidence from rocky shores and other well-known habitats suggests that these indirect effects, generically known as “trait mediated indirect interactions” may be at least as important as consumptive effects. Unfortunately, in habitats such as sedimentary bottoms, trait mediated interactions have not been given the same attention than consumptive effects. The alteration of a mid-level consumer’s trait, for instance its behavioral patterns or feeding rates, may have consequences that cascade down to lower trophic levels and, therefore, should be carefully examined. I propose to assess trait mediated indirect interaction in sedimentary bottoms by taking advantage of a series of species and habitats present in the Atlantic region. This program aims to test a series of hypotheses that relate to three parallel research scenarios: the assessment of trait versus density mediated interactions in marine sediments, the role of trait mediated interactions in the co-existence of multiple predators, and the study of trait mediated interactions in predatory invaders. Considerable exploratory work already conducted in sediments associated to scattered biogenic habitats (oyster, mussel and eelgrass beds) embedded with marine sediments provides the basis for the research questions raised in this proposal. Considering their scope, the results of this program are expected to contribute to the theory behind species interactions in coastal sediments and other marine habitats.