CRB: Collaborative Research: The Direct and Indirect Effects of Biological Invasions on Biodiversity in New England Kelp Beds

9700331 Coyer人类将物种引入其自然范围之外，正在迅速破坏地球的生物群，并对陆地，水生和海洋栖息地的生物多样性构成重大威胁。虽然几十年来人们已经认识到生物入侵对生物多样性的潜在影响，但直到最近，大多数研究都集中在陆地或淡水而不是海洋栖息地。人类引入的海洋物种数量众多，对一些当地人产生了巨大的影响。虽然在过去15年里对引进物种有了很多了解，但对海洋系统的概括却很难。这项研究将解决引进物种对西北大西洋海带床群落的影响。具体而言，本研究将探讨草食动物和竞争的相互作用对引进的松藻脆弱和本地海带社区的西北大西洋，苔藓虫对海带在这些社区的间接影响，以及增加松藻和减少海带生物量的鱼类和十足类，使用海藻床作为苗圃栖息地的人口的影响。 新英格兰的海带床群落在两种交替状态之间转换：一种是以海带为主的物种丰富的群落，另一种是以海胆和甲壳珊瑚藻为主的物种贫乏的群落。最近，一个新的社区，包括引进的绿色植物，松藻脆弱tomentosoides的单一栽培，现在在该地区流行。此外，苔藓虫的引入似乎也严重影响了海带床群落。通过一系列的多因素实验和描述性研究，本研究将阐明这种变化的原因，从而解释戏剧性的，人类引起的损失，在这些海带群落的生物多样性的机制。

9700331 Coyer Human introductions of species outside their natural range are rapidly homogenizing the earth's biota, and are a major threat to biodiversity in terrestrial, aquatic and marine habitats. Although the potential impact of biological invasions on biodiversity has been recognized for decades, until recently, most research has focused on terrestrial or freshwater rather than marine habitats. Anthropogenic introductions of marine species are numerous and have had a dramatic impact in some locals. While much has been learned about introduced species over the last 15 years, generalizations relative to marine systems are elusive. This study will address the effects of introduced species on kelp bed communities in the northwest Atlantic Ocean. Specifically, this research will examine the interactive effects of herbivory and competition on the introduced alga Codium fragile and the native kelp community of the northwest Atlantic, the indirect effects of a bryozoan on kelps in these communities, and the impact of increasing Codium and decreasing kelp biomass on the demography of fishes and decapods that use seaweed beds as nursery habitats. The kelp bed communities of New England shift between two alternate states: a species-rich community dominated by laminarian kelps, and a species-poor community dominated by sea urchins and crustose coralline algae. Recently, a new community consisting of a monoculture of the introduced green alga, Codium fragile tomentosoides, is now prevalent in the region. In addition the introduction of a bryozoan also appears to have severely impacted kelp bed communities. Using a series of multi-factor experiments and descriptive studies, this research will elucidate the causes of this shift in community structure, and therefore explain the mechanisms underlying the dramatic, human-induced loss of biodiversity in these kelp communities.