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

许多生物在空间上以离散的亚种群的形式分布，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总体种群动态、丰度或稳定性的了解很少。龙虾和螃蟹等底栖无脊椎动物种群分布在漫长的海岸线上。作为成虫，它们通常不会有太多活动，但有一个幼虫阶段，可以在洋流中活动数千公里。我们对幼虫移动了多远，如何随海洋条件变化，以及这些因素如何影响种群动态，知之甚少。沙蟹是一个很好的模式系统，因为成体和幼体数量丰富，无需复杂或昂贵的设备就可以很容易地进行采样。这种蟹分布在北美和南美洲的西海岸。在这个项目中，遗传标记和实地研究正在被用来更多地了解洋流如何将幼虫在从南加州到北加州海岸的一些成年种群中运输，以及随后种群动态如何受到影响。更好地了解通过幼虫扩散相互联系的海岸线上的种群动态，对于管理渔业、预测对污染的反应和预测气候变化的影响具有实用价值。在管理这种种群时，人们需要知道一个地点的繁殖如何影响另一个地点的人口，以及这如何影响人口动态。例如，这项研究将提供对一些近海种群不断增加的美国龙虾产量如何影响近岸渔业未来的理解。它还将告诉我们，俄勒冈州的石油泄漏将如何影响加利福尼亚州和华盛顿州的螃蟹渔业。

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.