The Seto Inland Sea, the biggest inland sea of Japan, is known for its high biodiversity. Advanced fishing techniques and fish farms boost the yield from the sea. However, since the 1960s, reclamation of coastal zones and the pollution and eutrophication of coastal waters, associated with the development of industries and human activities, have become obstacles for the management of fisheries and aquaculture in the Seto Inland Sea. The decrease in important fishery resources, such as the Japanese anchovy (Engraulis japonicus) or the Spanish mackerel (Scomberomorus niphonius), has been significant and fisheries were frequently affected by red tide. In 2010, fishery production in this area was about 180,000 tons, a 40–45% decrease relative to the 1980s.
It is decreasing continuously, except for some species such as Red seabream (Pagrus major), whose stock is in relatively good condition. In particular, disappearance of seaweed/seagrass beds and tidal flats, caused by reclamations, severely reduced the catch of species like the Manila clam (Ruditapes philippinarum) and the Kuruma prawn (Marsupenaeus japonicus), which utilize these areas as nurseries.
In addition, problems such as discoloration of cultured seaweed Nori and decrease in marine productivity due to shortage of nutrient salts in the sea water have recently emerged, though the issues of eutrophication have been solved by various effluent controlling measures based on The Law Concerning Special Measures for Conservation of the Environment of the Seto Inland Sea enforced in 1978.
The National Research Institute of Fisheries and Environment of Inland Sea (FEIS) plays two important roles: a regional fisheries research institute, responsible for the Seto Inland Sea, and a specialized research institute dealing with nationwide issues related to fisheries, such as harmful chemicals and red tides.
We have been continuing research and development to contribute to the resolution of the above-mentioned issues in fisheries and aquaculture industries in the Seto Inland Sea and the environment of Japanese fisheries ground.