Some effects of handling techniques on returns of tagged Australian salmon, Arripis trutta (Bloch & Schneider)

Abstract

Return rates of different tag types used on Australian salmon were briefly reviewed. Internal tags, especially with attached plastic streamers, were clearly superior. The effects of time held before tagging and injury (including scale removal) on return rate were investigated. There was no evidence of any mortality caused by these factors and salmon appear to be a robust species, little affected by the stress caused by tagging operations. However, when fish were held under adverse conditions for long periods, or when wounds were pronounced, behaviour changes were evident, which resulted in the non- participation of affected fish in movements from juvenile to adult areas. Such behavioural changes may be of importance in analysing tag data from other pelagic migratory species that could be more easily affected by stress.