Reduced fishing effort directed to North Pacific armorhead by Japanese vessels operating in the Emperor Seamount area

The recent low level of catch of North Pacific armorhead raised concern about the status of the stock. However, Japan informed that Japanese vessels have voluntarily avoided targeting NPA since 2019, suggesting that the catch level may not directly reflect stock level. In addition, this information led to the hypothesis that the setting of encouraged catch reduced directed fishing effort and fishing pressure on NPA, even though recent annual catch is smaller than the encouraged level. In this study, I tested the hypothesis by two approaches, i.e. the records of intended target by observers and the cumulative catch plots to specify target species in “directed CPUE” method. The results bore out the avoidance of targeting NPA and suggest that the implementation of encouraged catch might be effective in reducing directed fishing pressure on NPA by discouraging fishers against targeting the fish.