TAGGING EASTERN ROCK LOBSTERS JASUS-VERREAUXI - EFFECTIVENESS OF SEVERAL TYPES OF TAG

An experiment was done in the laboratory over 147 weeks to assess tag loss (tag-induced mortality plus tag shedding) in tagged or marked eas tern rock lobsters, Jasus verreauxi, The incidence of tag-induced mort ality, tag shedding or tag loss did not generally differ among tag typ es (toggle, T-anchor, dart tags), mark, or untagged lobsters, The exce ptions were that more untagged lobsters died between weeks 86 and 147 than lobsters tagged with T-anchor or dart tags, The percentages of lo bsters that died were 51, 45, 43, 47, and 62 for toggle, T-anchor, dar t, marked, and untagged treatments, respectively. An additional 18%, 2 2% and 23% of lobsters tagged with either toggle, T-anchor or dart tag s, respectively, shed their tag. None of the marked lobsters lost thei r marks. We conclude that no one type of tag used in the experiment wa s more suited to tagging J. verreauxi than another. Marking was discou nted as a technique to use in long-term experiments because, although the mark was still evident after 147 weeks, only trained observers cou ld recognise it, making the technique inappropriate for the general pu blic.