In order to evaluate how the marine ecosystems and social environments affect human well-being, feeling of satisfaction according to the five components of human well-being defined by the Millennium Ecosystem Assessment (Security, Basic material for good life, Health, Good social relations, and Freedom of choice and action) was examined by means of questionnaires. Structural Equation Modeling (SEM) analysis was applied to visualize the basic structure of human well-being and to compare among three Asian countries (Japan, Korea and Indonesia) which are highly dependent on fisheries. The SEM analysis showed that the three countries shared a common basic structure of the human well-being with the five components interacting with each other. However, the intensity of interaction between each component differed among the three countries. “Good social relationship” strongly influences “Freedom of choice and action” as the most important component in Japan and Korea, while “Health” does in Indonesia. Consideration of the differences in the structure of human well-being among the countries is suggested to be important for better conservation and management of marine ecosystems.

Japanese anchovy Engraulis japonicas is one of the main species for fisheries in Ise Bay. The factors that contribute to changes in the Japanese anchovy biomass in the bay have not been identified. The ratio of the catch per unit effort of Japanese anchovy inside the bay to that outside the bay (biomass index) was calculated between 1978 and 2003 to reveal its interannual changes. The entry of Japanese anchovy into the bay along with the bay-mouth water was observed from 1978 to 1994 when the Kuroshio Current was offshore and a large meander occurred frequently; such a coincidence was not observed in the bay after 1995 when the Kuroshio Current was onshore and a large meander hardly ever occurred. From 1999 to 2003, we estimated the Japanese anchovy biomass each month using a quantitative echo sounder in the north-eastern waters of the bay, and investigated the zooplankton density. From July to September (i.e. the main fishing season), a positive correlation was found between the Japanese anchovy biomass and zooplankton density. This showed that the bay serves as a feeding ground for Japanese anchovy. Consequently, the influence of offshore water and prey availability are important for determining Japanese anchovy biomass in Ise Bay.

In order to implement the rational stock management of Japanese eel Anguilla japonica, it is important to evaluate the fishing pressure (FP) on Japanese eel stocks by adult eel catch and glass eel catch equally. I accordingly developed a FP evaluation method that compares FP by adult eel catch with that by glass eel catch in the same dimension. I succeeded to clarify the historical changes of the relative relationship of both FPs by using it. According to this method, FP by 1 t of adult eel catch is equivalent to 16.4–120.0 kg of glass eel catch, and FP by adult eel catch continued to be stronger than that by glass eel catch until around the 1970s. However, FP by glass eel catch came to be dominant thereafter. In addition to the above, taking into account the estimation and comparison of both FPs, I considered the historical change of the stock level and the rational management measures for the current status of Japanese eel stocks.

The distribution and occurrence of cold water masses on the south side of the Kuroshio Current was examined in relation to the formation of fishing grounds for migrating skipjack. Fishing range of skipjack inshore pole fishery is formed in areas with sea surface temperatures lower than 19°C. To the south of the Kuroshio Current in spring, cold water mass with a sea surface temperature lower than 19°C sometimes stretches from the area north of 28°N, the Boso offing, to around 133°E of the Shikoku offing. Therefore, in years when a cold water mass occurred it was observed that the northward migration of skipjack was either blocked or bypassed the cold water mass. The northward migration course of skipjack and the time remaining in areas during its northward migration can be predicted from the water temperature on the south side of the Kuroshio Current during spring.