RAPID: COLLABORATIVE RESEARCH: Ecological & genetic recovery from a massive invertebrate die-off along the central coast of California

幼虫扩散在决定海洋无脊椎动物的基因流、分布和种群结构中可能发挥的重要作用仍然不清楚，尽管对远洋持续时间和种群遗传结构进行了数百次描述性比较。这种不明确性表明，许多因素可能会影响种群遗传结构，它们之间的相互作用可能是复杂的。研究这些因素的困难包括(在正常情况下)区分本地和外源招募，从而区分扩散距离的真实分布。例如，与许多海洋类群可能分散的距离相比，通常可以进行的探索这个问题的实验规模非常小。2011年8月，在加利福尼亚州中部海岸100公里处启动了一项大规模的自然迁移实验。PIS建议利用这个难得的机会来澄清扩散和物种相互作用对海洋种群遗传变异和群落结构的影响。他们建议研究三种死亡率非常高的物种：一种生态系统工程师(Strongyloctrotus PurPuratus，死亡率~100%)，一种关键物种(Pisaster ochraceus，死亡率~10%-70%)，以及它的竞争对手之一(Leptasterias sp.，死亡率~100%)。在自然大规模灭绝后的第一年，他们的目标是[1]量化目标物种在受影响范围内的物种丰度和分布，[2]开发和使用遗传标记来确定受影响范围内重新定居的赭鱼、纤毛虫和紫线对虾新成员的来源和扩散距离，以及[3]描述这三个物种及其猎物和竞争对手在整个受影响范围内的丰度变化。

The potentially important role that larval dispersal may play in determining gene flow, distributions, and population structure of marine invertebrates remains unclear despite many hundreds of descriptive comparisons of pelagic duration and population genetic structure. This lack of clarity suggests many factors may influence population genetic structure and their interactions may be complex. Difficulties studying these factors include (under normal circumstances) distinguishing local from exogenous recruitment and therefore the true distribution of dispersal distances. For example, experiments that normally could be undertaken to explore this issue are very small scale relative to the distances that many marine taxa may disperse.In August 2011, a large-scale natural removal experiment was initiated along a 100 km stretch of the central California coast. The PIs propose to use this rare opportunity to clarify the effects of dispersal and species interactions on marine population genetic variation and community structure. They propose to study three species that suffered very high rates of mortality: an ecosystem engineer (Strongylocentrotus purpuratus, ~100% mortality), a keystone species (Pisaster ochraceus, ~10-70% mortality), and one of its competitors (Leptasterias sp., ~100% mortality). Their objectives during this first year following the natural large-scale die-off are to [1] quantify the abundance and distribution of the target species at sites across the impacted range and reference sites to the south and north, [2] develop and use genetic markers to identify the sources and dispersal distances of new recruits of P. ochraceus, Leptasterias sp., and S. purpuratus that recolonize the impacted range, and [3] describe changes in abundance of these three species and their prey and competitors at sites throughout the impacted range.