Coastal Fishes in Tidal Flats and Salt Marshes

Tidal flats and salt marshes which are formed in the estuarine intertidal zones are important habitats for fishes worldwide. In this chapter, I outline the current status of tidal flats and salt marshes and their ecological roles for fishes, and review the conservation actions for intertidal fishes, focusing on the area of Japan. In the recent years, the economic value of these estuarine intertidal habitats and their conservation in Japan has been emphasized. However, due to urban development after 1945, intertidal environments such as tidal flats and salt marshes have disappeared significantly. Consequently, many species of fishes that mainly inhabit intertidal zones have become threatened. Compared to studies on fishes in tidal flats, few studies have focused on fishes in salt marshes in Japan. The intertidal habitats were seldom restored for the purpose of fish conservation in Japan, even though several studies have shown that these actions are effective. In the future, to conserve intertidal fishes, we should address the following four topics: (1) accumulation of ecological traits of these fishes, (2) restoration of large intertidal habitats, (3) adaptive management based on the results of long-term monitoring of mitigated/restored areas, and (4) identification of priority conservation areas managing fish diversity.