Effects of recreational angling on the post-release behavior and predation of bonefish (Albula vulpes):: The role of equilibrium status at the time of release

Even though the recreational fishery for bonefish (Albula spp) is predominantly catch-and-release, the effects of angling on individual behavior and survival are poorly understood. We used visual tracking to measure the short-term post-release behavior and survival of bonefish (Albula vulpes) in Eleuthera, The Bahamas, to determine if any specific aspects of the angling event were linked to post-release mortality, particularly via predation. Bonefish (n=88) were angled and landed using fly fishing equipment, affixed with a small float, and exposed to four treatments (released near or far from cover, with or without equilibrium). Following release, each fish was observed for up to I h, and specific swimming behaviors and incidences of predation were recorded. As a reference, a second group of bonefish (n = 20) was caught using a seine net and treated in a similar manner as angled fish. Fifteen (17%) of the angled bonefish suffered post-release predation by either lemon sharks (Negaprion brevirostris) or great barracuda (Sphyraena barracuda), while only one (5%) bonefish caught via seine was preyed upon. Released bonefish that had lost equilibrium were six times more likely to suffer predation than those released without losing equilibrium. In addition, longer durations of air exposure and handling times positively influenced the loss of equilibrium in bonefish. Proximity to mangrove cover, however, did not influence the susceptibility of released bonefish to predation. These findings suggest that post-release mortality of bonefish and potentially other marine fish released in high predator regions could be reduced by ensuring that fish are handled and released without leading to the loss of equilibrium. (c) 2007 Elsevier B.V All rights reserved.