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

RUI：有害藻华对高级海洋捕食者分布和生态的影响

• 批准号: 9726263
• 负责人: Rikk Kvitek
• 金额: $ 27.57万
• 依托单位: University Corporation at Monterey Bay
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2001-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9726263&HistoricalAwards=false
• 关键词: RUI; Influence; Harmful; Algal; Blooms

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.

一般的假设，觅食行为和分布的高层次的海洋捕食者（海獭和滨鸟）在自然条件下介导的底栖猎物毒性，由于有害藻华（HAB的）将在两个地理区域（加州和阿拉斯加）进行测试。由于底栖生物群落结构往往是通过捕食自上而下控制的，如果主要捕食者避免整个地区或猎物种群经常暴露于有毒水华，这些生境中的植物毒素的影响将进一步放大。在阿拉斯加东南部，海獭觅食是由麻痹性贝类毒素（PSPT）分布调节的一般假设将通过确定进行测试：1）不断扩大的阿拉斯加东南部海獭种群是否已经占据了黄油蛤蜊丰富但全年含有生物学显著水平的PSPT的内部通道地点，以及2）如果是这样，海獭是否已经将它们的饮食从主要的黄油蛤蜊猎物转移到替代的无毒物种，或者继续吃黄油蛤蜊，但可能会丢弃最有毒的身体部位。第二个研究部分将集中在三个常见的北方加州海岸鸟类（Godwits，Dowitchers，Oystercatcher）的两个主要的潮间带无脊椎动物猎物（鼹鼠蟹和贻贝）的PSPT含量的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介导PSPT的一般假设将进行测试，通过监测和相关的季节性变化，无脊椎动物的猎物毒性水平的变化，觅食行为和分布的鸟类在几个广泛分离的网站沿着加州海岸。