Wild migrating salmon smolts were trapped and PIT (passive integrated transponder) tagged on their way down river to the sea. The length and weight of each tagged fish was recorded. Half of the fish were bath treated with an anti-parasite lice treatment, and half left untreated as controls, before release and onward migration. Temporary adult salmon traps, or PIT tag detector systems, were built and deployed on the rivers to capture returning adult salmon from both groups, treated and untreated, and numbers were compared.
Reading and recording PIT tag number after delivery to fish, and prior to exposing to treatment or no treatment controls
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|Adult salmon trap, with PIT antenna attached ||View through PIT antenna attached to front of trapbox |