Estimates of tag shedding rates for Floy FT-2 dart and FD-67 anchor tags in Barramundi, Lates calcarifer (Bloch)

Abstract

A double-tagging experiment was carried out on a temporarily landlocked population of barramundi. Shedding rates were determined for Floy FT-2 dart tags on fish with a total length over 350 mm and FD-67 anchor tags on fish shorter than 350 mm. Immediate shedding was negligible for both tag types, and the estimated instantaneous daily shedding rate was 0.00057 for FT-2 tags and 0.0018 for FD-67 tags. Results from a small number of long-term recaptures suggest that the shedding rate may decline with time, so that tag loss over long periods could be overestimated if the above shedding rates are applied.