Regional Comparison of the Ecosystem Services from Seagrass Beds in Asia

Abstract

Coastal ecosystems offer valuable services to human society. However, these ecosystems are facing multiple impacts of human-induced stress, including overexploitation, eutrophication, land construction, and global climate change. The prediction of long-term changes in coastal ecosystems under multiple impacts is difficult because nonlinear and cumulative effects operate simultaneously. This difficulty is especially true for Asian regions, where coastal biodiversity is the world’s highest but the least studied. In this chapter, we compare ecosystem services of coastal areas of Asia based on the expert knowledge of practioners who study coastal ecosystems at each locality. We especially focused on seagrass beds, which provide important services to humans including provision of seafood and regulation of water conditions. We selected the six most important ecosystem services at each of 13 seagrass beds ranging from Japan to India and evaluated the direction of changes over the past two decades. We also evaluated public awareness and data certainty for each service. Food provisioning, water purification and waste treatment, erosion regulation, recreation and ecotourism, and educational values were selected as major ecosystem services of seagrass beds. Degradation during the over past 10–20 years was reported for most provisioning and regulating services, whereas improving trend was found for cultural services in most sites. Public awareness and certainty of information were generally high for provisioning services, but low for most regulating services. Regional variation along latitude, and differences between temperate and tropical seagrass beds, were not detected for the examined variables. Regional comparisons of ecosystem services shed light on general and specific aspects of the status of seagrass beds, which will provide baseline data for planning effective conservation and management strategies under multiple human impacts.