Collaborative Research: Kelp forest interaction webs in the Aleutian Archipelago: patterns and mechanism of change following the collapse of an apex predator.

合作研究：阿留申群岛的海带森林相互作用网：顶级捕食者崩溃后的变化模式和机制。

• 批准号: 0647844
• 负责人: Matthew Edwards
• 金额: $ 10.88万
• 依托单位: San Diego State University Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0647844&HistoricalAwards=false
• 关键词: Collaborative; Research; Kelp; forest; interaction

Research on sea otters and kelp forest ecosystems conducted over the past 35 years provides one of the better known examples of top-down forcing by a large vertebrate predator. These studies have shown that 1) sea otters indirectly maintain kelp forests by limiting herbivorous sea urchins, and 2) this trophic cascade has strong indirect effects on a number of other species and ecosystem processes. These insights were obtained largely through the comparison of islands in the Aleutian archipelago with and without sea otters, an opportunity created by the spatially asynchronous population recovery of sea otters following their decimation by the Pacific maritime fur trade. In the course of more than 35 years of studies, these researchers have obtained an extensive amount of data on sea otter populations, kelp forest communities, and an array of associated marine wildlife from numerous Aleutian Islands with and without sea otters. Sea otter populations have since collapsed and the species is now ecologically extinct across the entire region. In this study, Drs. Konar, Edwards and Estes will combine the multi-decadal database with this extinction event to chronicle the patterns and mechanisms of spatial and temporal change in distributions and abundances of sea urchins and fleshy macroalgae (kelps and other species). They will do this by revisiting 20 islands for which they have long-term data and re-censusing the historical kelp forest monitoring sites for the abundance and population structure of sea urchins, and for the abundance and species composition of kelps and other fleshy macroalgae. In combination, these data will provide an account of the degree to which the otter-urchin kelp trophic cascade has changed with the collapse of sea otters across the Aleutian archipelago.The available information indicates that kelp forests collapsed very rapidly following the sea otter decline, and that this rapid shift was facilitated by the upward migration of sea urchins from deep water as opposed to in situ recruitment and growth. This group of marine scientists will test this idea by measuring various temperature- and nutrient sensitive isotopic patterns along the growth increment of sea urchin spines of animals collected from shallow and deep water. Similar to a depth refuge for urchins, studies from other areas have suggested that macroalgae may have a spatial refuge from urchin grazing in shallow waters or amongst very dense algal stands. They will explore macroalgal spatial refuges by using data collected during the re-censusing of the kelp forest monitoring sites and by extending our surveys to shallower waters and isolated kelp beds.This research is an opportunity to rigorously explore and document the influences of a large vertebrate predator on the interaction web dynamics of its associated ecosystem. The intellectual merit of this project emphasizes the special character of oceanic islands and the Arctic for the study of near-shore ecosystem structure and processes.Broader impacts of this project include benefits to society, teaching, and training. The project will be very newsworthy because it will describe the current status of a rapidly declining marine mammal and will document changes that have occurred due to fluctuations in the abundance of this species over the last 20+ years. Training and educational opportunities will be offered to graduate students from three different universities. The project will involve the University of Alaska Fairbanks, University of California Santa Cruz, and San Diego State University.

过去35年中对海水獭和海带森林生态系统进行的研究为大型脊椎动物捕食者强迫自上而下的例子之一提供了研究。这些研究表明，1）海獭通过限制草食海胆间接地维护海带森林，而2）这种营养的级联对许多其他物种和生态系统过程都有强大的间接影响。这些见解主要是通过与有或没有海獭的阿留申群岛岛上的岛屿进行比较，这是由太平洋海洋毛皮贸易驱逐后的空间异步人口恢复所产生的。在超过35年的研究过程中，这些研究人员获得了有关海獭种群，海带森林群落以及来自众多阿留申岛群岛的一系列相关海洋野生动植物的大量数据。此后，海獭种群崩溃了，该物种现在在整个地区的生态灭绝。在这项研究中，博士。 Konar，Edwards和Estes将将多年数据库与此灭绝事件相结合，以记录分布分布的空间和时间变化的模式和机制，以及海胆和肉质宏观藻类（Kelps和其他物种）。 他们将通过重新审视具有长期数据的20个岛屿，并重新审查历史海关森林监测地点，以实现海胆的丰度和种群结构，以及海湾和其他肉质大宏观的丰度和物种组成。结合结合在一起，这些数据将说明水獭营养的级联反应随着阿留申群岛的海獭的崩溃而发生了变化。可用信息表明，海湾森林在海洋水獭的下降后迅速迅速崩溃，这种迅速转移的速度迅速迁移，并逐渐迁移到了向反对的狂热的迁移和反对的迁移，并逐渐偏向于水。这组海洋科学家将通过测量从浅水和深水收集的动物的海胆刺增长的生长增量来测量各种温度和营养敏感的同位素模式来测试这一想法。类似于顽童的深度避难所，来自其他地区的研究表明，大型藻类可能在浅水区或非常密集的藻类架中放牧的海胆避难所可能具有空间避难所。他们将使用在海带森林监测站点重新审查期间收集的数据，并将我们的调查扩展到较浅的水域和隔离的海带床，从而探索大藻类的空间避难所。这项研究是一种严格探索和记录大型脊椎动物捕食者对其相关的EcosStems的互动网络动力学的影响的机会。 该项目的智力优点强调了海洋岛屿的特殊特征以及北岸生态系统结构和过程研究的北极。该项目的影响包括对社会，教学和培训的好处。该项目将是非常新闻的，因为它将描述迅速下降的海洋哺乳动物的当前状态，并记录由于过去20多年中该物种的丰富性而发生的变化。将为来自三所不同大学的研究生提供培训和教育机会。该项目将涉及阿拉斯加大学Fairbanks，加利福尼亚大学圣克鲁斯分校和圣地亚哥州立大学。