마이크로네시아연방 축주 연안 잘피지역넷 저서동물의 군집의 공간 구조

Abstract

Reef-associated sea-grass beds are characterized by benthic community as well as coral-reef fishes as nursery. Sea-grasses are important in their interactions within coral reefs. These systems exert a stabilizing effect on the environment, resulting in important physical and biological support for the other communities. Seagrass providing food and shelter for diverse variety of organisms lagoon for many of reef species similar to mangrove forests in Chuuk. According to vertical scale from land to open sea by transect method using quadret, benthic community structure have been influenced by several types of habitats based on sea-grass beds such as density and species composition. The seagrass bed is dense and mostly sandy on the area close from coastline to middle of area of the end of reefs sheltered. Coverage by three of species, Cymodocea rotundata, Enhalus acoroides and Syringodium isoetifolium dominated over 70% at this area. But it showed the changes by spatially. A total of 14 species of macro-invertebrate were associated with all seagrass beds. Holothuroideans, Synaptula sp., Bohadschia mamorata, and Holothuria hilla were commonly distributed, and echinoideans Echinothrix sp., Mespilia globules and Tripneustes gratilla also observed neighboring of middle area which sea-grass showed sparse density. As results by multivariate analysis, based on the number of density of each species, spatial distribution of benthic community showed clear separation along the transect. Sea-grass density influenced to the sedimentary characteristics as well as reef formations. It also may affected to the benthic community in reef area .