Short communicationA cage release method to improve fish tagging studies

- Newly designed cage for the release of transmitter tagged fish.
- Cage protects from predators and remotely opens on the seafloor.
- Successful for two fish species (Lutjanus campechanus and Balistes capriscus).
- No initial tag induced mortalities were observed.
- Used to release transmitter tagged fish on artificial reefs in the northern Gulf of Mexico.

The return and survival of tagged fish to their depth of capture has proved difficult due to barotrauma and predation in previous telemetry studies. Tagging stress can slow and disorient the fish upon release, and reduce the ability to return to depth, relocate their home habitat site, and evade predators. To reduce these initial tag and release artifacts we designed and tested a remotely opening cage for use with reef fish in the northern Gulf of Mexico. Our objectives were to quickly return transmitter tagged fish to depth (20-30 m) in close proximity (<10 m) to their capture site, and to increase survival by providing predator protection during an initial recovery period. This cage release method proved successful for both red snapper (Lutjanus campechanus; n = 62 out of 71, 87%) and all gray triggerfish (Balistes capriscus; n = 24) that were tagged and released on artificial reefs. All tagged fish were released from November 2012 to September 2014, no initial tag induced mortalities were observed, and after tagging fish were successfully tracked for extended periods (for the entire 2 year study period).