Evaluation of Radio Telemetry to Study the Spatial Ecology of Checkered Puffers (Sphoeroides Testudineus) in Shallow Tropical Marine Systems

Knowledge of the spatial ecology of fishes aids in conservation management and informs the sustainable use of natural resources, although the techniques used to monitor movements are often restricted by the habitats occupied by fishes and our inability to observe them. Due to the rapid attenuation of acoustic signals in shallow (<0.3 m) estuarine environments, we examined the applicability for a novel use of radio telemetry to examine the spatial ecology of checkered puffers, Sphoeroides testudineus Linnaeus, 1758, in shallow, tropical tidal creeks. External attachment of radio tags on the dorsal surface of the caudal peduncle resulted in reliable retention (100% after 5 d) for short-term applications, and no differences were observed in swimming ability or standard metabolic rate between tagged individuals and untagged controls. However, external tagging resulted in significant postural differences during routine activity in comparison to untagged controls, although we demonstrate that this can be eliminated by reducing tag burden in future studies. A small sample of puffers (n = 5) was subsequently radio tagged and released into a shallow tidal creek whereby attempts were made to relocate individuals both visually and using radio telemetry over a short period (1 hr). Checkered puffers exhibited an ability to move the entire length of a small tidal creek (maximum mobility 389 m), although using radio telemetry to monitor the movements of puffers had limited application with the techniques applied in the present study when individuals occupied water depths >0.2 m and were actively swimming. With minor modifications to tags and by reducing tag burden, radio telemetry could serve as a feasible means of monitoring the movements of site-associated species in shallow tidal creeks.