Estimating tag-shedding rates for skipjack tuna, Katsuwonus pelamis, off the Maldives

The Ministry of Fisheries and Agriculture, Maldives, carried out two tagging experiments: one in 1990-91 (Yesaki and Waheed, 1992) and the other between 1993 and 1995 (Anderson et al., 1996). The latter tagging experiment included a double tagging experiment in which 504 skipjack tuna, Katsuwonus pelamis, were double tagged, by using the same type of tags and techniques of tagging as used in the single tagging experiment (Anderson et al., 1996). As of end 1996, a total of 53 of these fish had been recovered. These data are considered to be of immediate importance for designing large-scale experiments in the Indian Ocean, strategic tagging simulation studies (e.g. Bertignac, 1996), and for comparing the estimated rates with those obtained from similar tuna double tagging experiments conducted elsewhere. Our note reports estimates of tag-shedding rates carried out in the Maldives.