ANALYSIS OF ROSS SEA TAGGING AND RECAPTURE RATES

1. A dataset of all possible combinations of release nation, recapture nation, release year and recapture year for tags released and recaptured in the same SSRUs on the slope of 88.1 was compiled for the years 2003-2006. Recapture rate was expressed as tags captured/tags released/fish scanned (caught), all in numbers. 2. The overall size of the dataset was 734 combinations of release year, recapture year, SSRU, release nation and recapture nation, with 193 recaptures. Despite this size, fishing has not been consistent enough between nations to allow the analysis to be definitive. In many cases, release or recapture nation effects were not significant. In the cases where significant differences existed, recapture rates were usually highest with New Zealand tagged and recaptured fish, although there was some evidence for suggesting that recapture rates are highest when the fleet and tagging fish is the same. 3. This method could be used to identify groups of nations that have similar reporting rates, for inclusion in the Ross Sea stock assessment.