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

[902218]许多生物在空间上以离散的亚种群分布，只有当它们之间的某些生命阶段移动时才相互作用。然而，我们对这些元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甚少。像龙虾和螃蟹这样的底栖无脊椎动物种群分布在长长的海岸线上。它们成年后通常不怎么移动，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，海洋条件的变化，以及这些如何影响种群动态都知之甚少。沙蟹（Emerita analoga）是一个很好的模型系统，因为它的成虫和幼虫数量丰富，而且可以很容易地取样，而不需要复杂或昂贵的工具。这种螃蟹分布在北美和南美的西海岸。在这个项目中，正在利用遗传标记和实地研究来更多地了解洋流如何将幼虫沿着海岸从南加州运送到北加州，以及随后如何影响种群动态。更好地了解沿海种群的动态，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，人们需要知道一个地方的繁殖如何影响另一个地方的种群，以及这如何影响种群动态。例如，这项研究将有助于了解美国近海龙虾产量的增加如何影响近岸渔业的未来。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.