Elucidation of production process of fishery resource and evaluation of ecosystem function in coastal area

Coastal zones composed of a variety of ecosystems such as seagrass and macroalgal beds, tidal flats, coral reefs and estuaries have high biodiversity and biological productivity. These ecosystems provide high ecosystems services, the economic value of which is estimated to be the highest among all the ecosystems on the planet, including terrestrial ecosystems. On the other hand, degradation of coastal ecosystems is progressing throughout the world. The development and disappearance of coastal ecosystems affect fishery production because coastal ecosystems are important as a habitat for many fishery resources. However, to date, there has been limited information on quantitative evaluation of the impact of each ecosystem on fishery resources. Clarification of the process of biological production in each ecosystem is essential for appropriate conservation of the ecosystems and efficient management and restoration of the fishery resources living there. Recently, it has been recognized that many species of fishery resources inhabit single multiple ecosystems throughout their lifetime. Coastal zones are exactly aggregates of heterogeneous ecosystems. Therefore, it will be increasingly important to evaluate the connectivity of different ecosystems and contribution of each ecosystem to fishery production. Perspectives based on large-spatial and comprehensive viewpoints that clarify the real status of migration of substances and organisms among different ecosystems, in addition to quantitative evaluation of biological production process in each ecosystem, are indispensable. To attain sustainable use of the ecosystem services, including fishery resources, social practices according to characteristics of the various functions of ecosystems, environmental and local social conditions are indispensable. This paper summarizes a couple of results from research made by the author on evaluation of fish production, spatial variability of fish community structures, and ecosystem services and their annual fluctuations in coastal ecosystems.