SGER: Examining the Impact of Land-Use on Offshore Sediment Transport and Reef Degradation during a Category Five Hurricane on a Mountainous Caribbean Island: Roatan, Honduras

尽管人们普遍认为，发展可能对近岸珊瑚礁生态系统产生各种负面影响，但研究人员很难将具体的土地利用做法直接与自然环境的变化联系起来，并最终与珊瑚礁退化联系起来。该项目将利用以前收集的物理和生物数据，结合米奇飓风（本世纪该地区最大的风暴）后收集的新数据，研究各种土地利用做法如何影响加勒比海沿岸发展中的多山海岸线的沿海风暴过程。罗阿坦岛是海湾群岛中最大的岛屿，这是一个距离洪都拉斯北海岸约60公里的岛屿链。海湾群岛是伯利兹珊瑚礁系统的一部分，这是世界上第二长的珊瑚礁地带。为了应对日益增长的发展，1998年夏天启动了一项长期监测计划。该项目包括沉积物积累、沉积物空间分布、陆源沉积物输入、活珊瑚百分比、水质和粪便大肠菌群细菌的监测。罗阿坦岛是一个多山的岛屿，可以分为不同的流域，有不同的近岸生态系统，沿着海岸几乎没有明显的沉积物交换或其他物理特征。这为研究特定土地使用做法对近海物理参数的影响，并最终对珊瑚礁的影响提供了一个自然环境。监测站的设置是为了监测近海流域的情况，这些流域有不同类型的土地利用、不同的排水方式和不同的人类影响。例如，在一个陡峭的分水岭附近有一个地方几乎没有开发，但它已经被清理出来放牧。在一个类似的流域附近有一个地点正在被细分和开发，在一个类似的流域附近有一个控制点，那里完全没有人为影响。我们希望能够直接将特定的土地使用实践与风暴引起的离岸物理参数变化联系起来，然后评估对珊瑚死亡率的任何影响。由于基线数据是在飓风到来之前很快收集的，而且在地点放置和风暴通过之间没有其他事件，因此应该有一个关于风暴造成的破坏的良好记录。这项研究将第一次很好地估计不同的土地利用对珊瑚死亡率的相对影响，这是对大型热带系统通过的反应。所收集的数据将具有重要的科学和管理意义。

Young OCE 9903922Although there has been a general understanding that development may have a variety of negative impacts on nearshore reef ecosystems, researchers have had difficulty tying specific land use practices directly to changes in the physical environment, and ultimately to reef degradation. This project will use previously collected physical and biological data, combined with new data collected after Hurricane Mitch (the largest storm in the region this century) to examine how various land use practices impact coastal storm processes along a developing, mountainous Caribbean shoreline. The island of Roatan is the largest of the Bay Islands, a chain of islands roughly 60 km off the north coast of Honduras. The Bay Islands are a part of the Belize Reef System, the second longest coral reef tract on the globe. In response to the certainty of increased development, a long-term monitoring program was initiated in the summer of 1998. This program involves the monitoring of sediment accumulation, sediment spatial distribution, terrigenous sediment input, percent live coral, water quality, and fecal coliform bacteria. Roatan is a mountainous island that can be divided into distinct watersheds with distinct nearshore ecosystems that have little apparent exchange along shore of sediment or other physical characteristics. This provides a natural setting to study the impacts of particular land-use practices on offshore physical parameters, and ultimately on the reef. Monitoring stations were placed to monitor conditions immediately offshore of watersheds with varying types of land use, varying drainage, and varying human impact. For example, there is a site offshore of a steep watershed that has little development, but it has been cleared for grazing cattle. There is a site offshore of a similar watershed that is being subdivided and developed and a control site offshore of a similar drainage where there has been no human impact at all. We hope to be able to directly tie particular land-use practices to storm-induced changes in offshore physical parameters, and then assess any impact to coral mortality. Because baseline data were collected so soon before the hurricane, and there were no other events between site placement and the storm's passage, there should be an excellent record of storm-caused damage. This study will provide the first good approximation of the relative impact of varying land use on coral mortality in response to the passage of a large tropical system. The data gathered will be of important scientific and management interest.