Cryptic density dependence: the effects of spatial, ontogenetic, and individual variation in reef fish

长期以来，生态学家一直对驱动人口密度和结构时空变异的因素感兴趣。在海洋珊瑚礁系统中，注意力集中在沉降的作用-浮游幼虫向底栖阶段的过渡-以及影响最近定居的幼鱼的密度依赖过程。最近的数据表明，协方差在结算和随后的密度依赖生存可以掩盖密度依赖的模式，在较大的规模，一种现象称为神秘的密度依赖。本研究将探讨沉降和场地质量的空间协方差的机制--这一过程在标准范式中很少受到关注。这些神秘的密度依赖机制的研究，将促进鱼类种群动态，包括幼虫生态，栖息地质量，密度依赖，生活史，以及这些因素之间的空间协方差的模式和影响的新框架的发展。更一般地说，这项工作提供了一个具体的经验背景，和一个一般的理论处理，神秘的异质性（隐藏的人口统计率的个体差异）。 本项目的培训将涉及定量和实验海洋生态学的本科生和研究生。 此外，本科生将通过监督研究课程参与。 学生将接受现场和实验室技术培训;他们还将有机会与来自澳大利亚和新西兰的合作者合作。该项目对海洋渔业的管理具有更广泛的影响，包括捕捞的食用渔业（很少能进行实验研究，因此可能表现出神秘的密度依赖性）和海洋生物（为水族馆贸易捕捞的鱼类和无脊椎动物），可以很好地进行研究，但科学与管理和政策之间存在重大分歧。

Ecologists have long been interested in the factors that drive spatial and temporal variability in population density and structure. In marine reef systems, attention has focused on the role of settlement-the transition of pelagic larvae to a benthic stage-and on density-dependent processes affecting recently settled juveniles. Recent data suggest that co-variance in settlement and subsequent density-dependent survival can obscure the patterns of density dependence at larger scales, a phenomenon called cryptic density dependence. This research will explore the mechanisms that underlie the spatial covariance of settlement and site quality - a process that has received little attention in the standard paradigm. These mechanistic studies of cryptic density dependence will facilitate the development of new frameworks for fish population dynamics that incorporate larval ecology, habitat quality, density dependence, life history, and the patterns and implications of spatial covariance among these factors. More generally, the work provides a specific empirical context, and a general theoretical treatment, of cryptic heterogeneity (hidden individual variation in demographic rates). Training in this project will involve undergraduate and graduate students in quantitative and experimental marine ecology. Additionally, undergraduates will be involved through supervised research courses. Students will be trained in field and lab techniques; they will also have the opportunity to work with collaborators from Australia and New Zealand. This project has broader implications for the management of marine fisheries, including harvested food fisheries (which can seldom be studied experimentally and thus probably exhibit cryptic density dependence) and marine ornamentals (fish and invertebrates harvested for the aquarium trade) which can be studied well but for which there is a significant divide between science and management and policy.