Establishment of preserved area for snow crab Chionoecetes opilio and consequent recovery of the crab resources

Abstract

Snow crab stocks in the westem Sea of Japan have been overfished by the Danish seiners. Six preserved areas were established off Kyoto Prefecture from 1983 to 1999, where artificial reefs made of concrete blocks were provided and all the crab fisheries were closed. As a result, functionally matured males and fully matured females aggregated to the first preserved area. CPUE and survival rates of both adult males and females were higher in the preserved area than that in the outside. The average annual catch from 1995 to 1999 expanded about 75% compared with ones from 1978 to 1982. Our survey suggested that a preserved area with artificial reefs provide protection from over-exploitation by Danish seiners for matured crabs as well as providing suitable habitat for recruiting juveniles.