Analysis of trends in Japanese krill fishery, and its implication

Haul by haul logbook data from the Japanese krill fishery from 1980/81 to 2003/04 fishing season was analysed. By using statistical modeling (linear mixed model) a series of predicted intra- and inter-annual trends of standardized fishery indices are presented. The results strongly suggest that krill fishery in South Orkney and South Georgia area are both operating around a critical point which is just enough to maintain the best factory performance. The status of fishing was not clear in Subarea 48.1 through our analysis. Linear correlation was observed between Catch per Searching Time and Catch per day within their lower range, suggesting these may have some value as abundance index. To refine these indices, it is necessary to collect more detailed information from fishing vessels. It is also important to undertake the same kind of analysis for the fleets from other fishing nations.