Retention and in situ detectability of visible implant fluorescent elastomer (VIFE) tags in Pagrus auratus (Sparidae)

This paper assesses the potential effectiveness of the visible implant fluorescent elastomer (VIFE) tagging system for identifying groups of snapper (Pagrus auratus: Sparidae) in the field. Retention rate after surface tagging longline‐caught fish was 93% over a 2‐week period, with no mortality attributable to tagging. Incidence of fin or scale infection did not differ between tagged and control fish. A protocol for tagging snapper underwater was also developed. This technique caused less stress to the fish than remote fishing methods, but was labour intensive when large sample sizes were required. Orange VIFE tags were visible to divers at ranges of up to 6 m in water visibility of 8–10 m, when exposed to light frequencies capable of inducing fluorescent emissions. Red, green, and yellow tags were only identifiable at shorter ranges, depending on ambient light levels and direction. The range of tag detection increased with increasing water clarity. We suggest that VIFE tagging has better retention rates and is less intrusive compared with previously employed externally readable tags. Because tags are identifiable in situ without the necessity of recapture, this method has potentially wide‐ranging applications in fish ecology and behavioural studies for adult as well as juvenile fishes.