Dissertation Research: Demographic and Genetic Analysis of Metapopulation Dynamics: Emerita analoga as a Model Organism

9902218 Botsford，Diehl Grosberg许多生物体作为离散的亚群分布在太空中，只有当某些生命阶段在它们之间移动时才会相互作用。然而，我们对这些集合种群的迁移率和空间结构如何影响整体种群动态、丰度或稳定性的了解甚少。底栖无脊椎动物如龙虾和螃蟹的种群分布在沿着漫长的海岸线。它们通常不像成年人那样移动，但有一个幼虫阶段，可以在洋流中移动数千公里。我们对幼虫移动的距离，如何随海洋条件变化以及这些如何影响种群动态知之甚少。沙蟹，Emerita analoga，是一个很好的模式系统，因为成年人和幼虫是丰富的，可以很容易地采样，没有复杂或昂贵的齿轮。这种蟹分布于沿着南北美洲的西海岸。在这个项目中，遗传标记和实地研究被用来更多地了解洋流如何在从南加州到北方加州海岸的一些成年种群中运输幼虫，以及随后如何影响种群动态。更好地了解沿着种群的动态，通过分散幼虫相互联系，在管理渔业、预测对污染的反应和预测气候变化的影响方面具有实际价值。在管理这类种群时，需要了解一个地点的繁殖如何影响另一个地点的种群，以及这如何影响种群动态。例如，这项研究将提供如何增加美国龙虾从一些近海种群的收获影响近岸渔业的未来的理解。它还将告诉我们，俄勒冈州的石油泄漏将如何影响加州和华盛顿的螃蟹渔业。

9902218Botsford, Diehl & Grosberg Many organisms are distributed as discrete subpopulations over space, interacting only when certain life stages move between them. However, we have a poor understanding of how migration rates and spatial structure of these metapopulations affect overall population dynamics, abundance, or stability. Populations of benthic invertebrates like lobsters and crabs are distributed along long stretches of coastline. They commonly do not move much as adults, but have a larval stage that can move about in ocean currents for thousands of kilometers. We have a poor idea of how far larvae move, how that varies with ocean conditions, and how these influence population dynamics. The sand crab, Emerita analoga, is a good model system because the adults and larvae are abundant and can easily be sampled without complicated or expensive gear. This crab is distributed along the west coast of North and South America. In this project genetic markers and field studies are being used to learn more about how ocean currents transport larvae among a number of adult populations along the coast from southern California to northern California, and how population dynamics are subsequently affected. Gaining a better understanding of the dynamics of populations along coastlines, interconnected by dispersing larvae has practical value in managing fisheries, predicting responses to pollution, and anticipating the effects of climate change. When managing such populations, one needs to know how reproduction at one location contributes to populations at another location, and how this affects population dynamics. For example, this study will provide understanding of how increasing harvests of American lobsters from some offshore populations affects the future of nearshore fisheries. It will also tell us how an oil spill in Oregon would affect the crab fisheries in California and Washington.