2005 年 9 巻 2 号 p. 139-149
Ise Bay is a shallow semi-closed bay located in central Honshu Island, Japan, facing the Pacific Ocean. This bay provides one of the major fishing grounds for Pacific sandeel, Ammodytes personatus Girard, in Japan. Sandeel juveniles targeted by the fisheries in Ise Bay are mainly caught by pelagic-trawl fleets consisting of two net boats and one or two transport boats. At present about 200 fleets are engaged in this fishery. The lifespan and maximum body size of Pacific sandeel are three years and about 16 cm, respectively. The stock of sandeels in Ise Bay once collapsed between the late 1970s and early 1980s for five years because of over-exploitation and environmental deterioration. After the collapse in 1980, fishermen and researchers started to conduct regulatory measures on a collaboratory basis between the two prefectures surrounding Ise Bay. In 1990 they decided on three measures to establish management as follows: 1) protection of spawners, 2) setting an opening day and 3) setting a closing day for the sandeel fisheries. Sandeels have a characteristic behavior of burrowing into sand for aestivation during May to November. Using this unique property, the number of spawners could be controlled through establishment of a closing day for fishing. This helps to control and survey the number of spawners. Protecting spawners for successive reproductive seasons and establishment of a Marine Protected Area (MPA) have played an important role in adaptive management. The area of the MPA increased if the remnants of the stock are small. Community-based unions play an important role in enforcing these management measures.
