RUI: Influence of Harmful Algal Blooms on the Distribution and Ecology of High Level Marine Predators

在加利福尼亚和阿拉斯加这两个地理区域，将对自然条件下高级海洋捕食者（海獭和滨鸟）的觅食行为和分布的一般假设进行测试，该假设是由有害藻华（HAB’s）引起的底栖猎物毒性介导的。由于底栖生物群落结构通常由上而下通过捕食来控制，如果主要捕食者避开整个地区或经常暴露于有毒水华的猎物种群，植物毒素对这些栖息地的影响将进一步扩大。在阿拉斯加东南部，海獭觅食受麻痹性贝类中毒毒素（PSPT）分布调节的一般假设将通过确定：1)是否扩大东南阿拉斯加海獭数量已经占据内航道地点奶油蛤丰富但包含生物重要PSPT水平,和2)如果是这样,是否海獭要么改变他们的饮食远离他们的主要奶油蛤猎物替代非有毒物种,还是继续吃奶油蛤蜊,但也许而丢弃最有毒的身体部位。第二个研究部分将集中于三种常见的北加州滨鸟（Godwits, Dowitchers, oystercatch）对两种主要潮间带无脊椎动物猎物（鼹鼠蟹和贻贝）PSPT含量可预测的季节性增加的反应。这些鸟类捕食者的觅食策略也由PSPT介导的一般假设将通过监测和将无脊椎动物猎物毒性水平的季节性变化与鸟类觅食行为和分布的变化相关联来验证。

The general hypothesis that the foraging behavior and distribution of high level marine predators (sea otters and shorebirds) under natural conditions are mediated by benthic prey toxicity due to harmful algal blooms (HAB's) will be tested in two geographic regions regions (California and Alaska). Because benthic community structure is often controlled from the top down via predation, the influence of phytotoxins in these habitats will be further amplified if key predators avoid entire regions or prey populations regularly exposed to toxic blooms. In southeast Alaska, the general hypothesis that sea otter foraging is regulated by paralytic shellfish poisoning toxins (PSPT) distribution will be tested by determining: 1) whether or not the expanding southeast Alaskan sea otter population has occupied inside passage sites where butter clams are abundant but contain biologically significant levels of PSPT year round, and 2) if so, whether the sea otters have either shifted their diet away from their primary butter clam prey to alternate non toxic species, or are continuing to eat butter clams, but perhaps while discarding the most toxic body parts. The second research component will focus on the response of three common northern California shore birds (Godwits, Dowitchers, Oystercatchers) to the predictable seasonal increase in the PSPT content of two major intertidal invertebrate prey (mole crabs and mussels). The general hypothesis that the foraging strategies of these avian predators is also mediated by PSPT will be tested by monitoring and correlating seasonal changes in invertebrate prey toxicity levels with changes in the foraging behavior and distribution of the birds at several widely separated sites along the California coast.