アマモ場の生物多様性·生態系モニタリング

摘要

Seagrass bed is one of the most important components in coastal ecosystem, but is declining rapidly due to various human-induced threats. Long-term, broad-scale monitoring of seagrass beds is necessary to promote conservation and wise management of seagrass beds. This article reviews and dis-cusses some important issues toward establishing effective and sustainable monitoring programs on biodiversity and ecosystem functions of seagrass beds. Biodiversity and ecology of seagrass beds vary gratly, especially between tropical and temperate regions, and along depth gradient. The patterns of varia-tion affect monitoring designs of each program. The methods of monitoring differ greatly among major monitoring programs conducted at global scales. The major differences in methods include whether census is repeated at fixed point or randomly, whether it is based on destructive samplings or non-destructive census, and whether census is restricted to seagrass or it includes seagrass-associated animal assem-blages. An integrated approach combining field monitoring data and remote sensing data by GIS enables one to evaluate spatial variation in major ecosystem functions of seagrass beds, such as photosynthesis ability and biomass, which would be utilized for various projects on conservation and management of coastal ecosystems.