COMPARISON OF DATA FROM VOLUNTARY LOGBOOK AND RESEARCH CATCH-SAMPLINGPROGRAMS IN THE NEW-ZEALAND LOBSTER FISHERY

Since 1993, the New Zealand Fishing Industry Board has run an extensiv e voluntary programme to collect biological information from rock lobs ter (Jasus edwardsii) pot fisheries using logbooks maintained by comme rcial fishers. The New Zealand Ministry of Fisheries has run since 198 9 an intensive research sampling programme of the rock lobster commerc ial fishery which measures nearly every lobster caught in a selected t rip. A comparison of these two programmes was made for the southern So uth Island fishery over a period from August 1993 to January 1996. Len gth frequency distributions stratified by month and statistical area s howed similar distributions from both sampling programmes in most stra ta, with a tendency for higher frequency modes to be estimated by the voluntary logbook data and larger frequency modes estimated by the res earch sampling data. These differences were slight except for five ins tances (of 40 strata compared) where the research sampling programme e stimated flat frequency distributions which were not typical of the di stributions estimated in other strata. Catch per potlift from the volu ntary logbook programme and the compulsory catch per effort landing re turns were similar for the same fishers. This indicated that the volun tary fishers were successful in designating 'representative' sampling units for their programme.