The physiological stress response, postrelease behavior, and mortality of blacktip sharks (Carcharhinus limbatus) caught on circle and J-hooks in the Florida recreational fishery

Abstract

The blacktip shark (Carcharhinus limbatus) is the most commonly captured species in the Florida recreational shark fishery. We aimed to quantify the postrelease mortality of blacktip sharks and to determine whether hook type (circle or J) had any impact on survival. We measured capture variables (e.g., fight time, animal condition, etc.), blood gas analytes, and finescale behavior obtained by using acceleration data loggers for blacktip sharks (n=31) caught on rod and reel by recreational fishermen. Mortalities (n=3; 9.7%) all occurred within 2 h after release. Surviving sharks were monitored for 7 to 72 h (mean: 30 h [standard deviation (SD) 22]) and behaviorally recovered from capture within 11 h (SD 2.6), although larger individuals recovered faster. Hook type did not affect where a shark was hooked, animal condition, the likelihood of hook removal, or recovery time. We found relatively low levels of mortality for blacktip sharks caught in the recreational fishery that were kept in the water and had not sustained serious injuries.