Cascading effects of predator diversity in a marine food web

知识价值：海洋生物多样性的一般意义已被广泛接受。例如，有几个令人信服的例子说明遗传、物种和功能群体多样性在调节海底海洋生境的群落生产力、可入侵性和稳定性方面的重要性。这种经验研究和基本生态理论支持这样的主张，即保护生物多样性应是保护的首要任务。然而，由于对捕食者多样性影响的实验研究很少，我们无法预测，甚至可能无法认识到捕食者排斥的级联效应。由于过度捕捞和栖息地丧失，几乎所有水生和陆生群落中的脊椎动物捕食者的多样性都已下降，有时甚至急剧下降。这种现象在一些海洋生态系统中尤其有据可查，过度捕捞使顶级捕食者的生物量减少了85%，物种丰富度减少了10- 50%。为了了解海洋捕食者组成和多样性的这些变化的后果，我们显然需要开始在海洋生态系统中进行相关的实验。本研究将通过操纵北卡罗来纳州的底栖河口食物网结构来确定捕食者组成和多样性对较低营养级的级联效应。使用一个多样化的和经过充分研究的大型藻类，大型无脊椎动物食草动物，甲壳类和脊椎动物捕食者的社区，调查人员将在现场和户外围隔生态系统中进行实验，以回答三个基本问题：问题1：捕食者的身份和丰富度如何直接影响食草动物社区？ 问题2：捕食者身份和丰富度如何间接影响植物群落和初级生产力？问题3：猎物移民介导捕食者多样性效应吗？ 更广泛的影响：该项目将扩大弗吉尼亚海洋科学研究所（VIMS）和弗吉尼亚海洋科学研究所（IMS）的研究人员之间正在进行的合作，研究海洋植物和草食动物生物多样性与生态系统功能之间的关系。这项研究将是任何生态系统中的第一项此类研究，并符合NSF生物海洋学计划重点的海洋系统生物多样性特别主题。研究结果将帮助科学家和政策制定者了解捕食者多样性下降的后果，通过帮助保护类似的系统，可能造福社会。其他更广泛的影响将来自几个外联活动，包括：初中和高中学生的辅导，与莫尔黑德天文馆和科学中心组织的夏季海洋生态儿童营，以及与国家渔业管理人员和当地渔民的密切合作。

Intellectual merit: The general significance of marine biodiversity is widely accepted. For example, there are several compelling examples of the importance of genetic, species, and functional group diversity in regulating community productivity, invasibility, and stability in benthic marine habitats. Such empirical research and basic ecological theory support the assertion that preserving biodiversity should be a top conservation priority. Yet because there have been few experimental investigations of the effects of predator diversity, we cannot predict and may not even recognize the cascading effects of predator extinctions. The diversity of vertebrate predators has declined, sometimes precipitously, in nearly all aquatic and terrestrial communities as a result of over harvesting and habitat loss. This phenomenon is especially well documented in some marine ecosystems where over fishing has reduced top predator biomass by 85% and species richness by 10-50%. To understand the consequences of these changes in marine predator composition and diversity we clearly need to begin to perform relevant experiments in marine ecosystems. This study will determine the cascading effects of predator composition and diversity on lower trophic levels by manipulating the structure of a benthic estuarine food web in North Carolina. Using a diverse and well-studied community of macroalgae, macroinvertebrate herbivores, and crustacean and vertebrate predators, the investigators will perform experiments in the field and in outdoor mesocosms to answer three basic questions: Question 1: How does predator identity and richness directly affect herbivore communities? Question 2: How does predator identity and richness indirectly affect plant communities and primary production? Question 3: Does prey immigration mediate predator diversity effects? Broader impacts: This project will expand ongoing collaboration between researchers at the Virginia Institute of Marine Science (VIMS) and the UNC's Institute of Marine Science (IMS) on the relationships between marine plant and herbivore biodiversity and ecosystem functioning. This research will be the first of its kind in any ecosystem and fits within the Biological Diversity in Marine Systems special theme of emphasis of the NSF Biological Oceanography Program. The results will help scientists and policy makers understand the consequences of declining predator diversity, potentially benefiting society by helping to conserve similar systems. Additional broader impacts will result from several outreach activities including: the mentoring of middle and high school students, summertime marine ecology children's camps organized with the Morehead Planetarium and Science Center, and a close collaboration with state fisheries managers and local fishers.