The tagging procedure for both tags resulted in externally visible lesions in 10% of fish. The most
obvious of these were not associated with the tagging procedure, but were due to infection with the
monogenean ectoparasite Benedenia sekii. This parasite occurs naturally on snapper in New Zealand
(Roubal et al. 1983, Sharples & Evans 1995), but tends to build up on fish confined in seacages
(Roubal et al. 1996, Diggles et al. 2001). The normal presence of similar parasite-associated lesions
on wild fish would appear to make it difficult, if not impossible, for commercial and recreational
fishers to detect tagged fish from simple external examination, at least after 12 weeks post-tagging.