![]() ![]() Reflexes (nictitating membrane (NM), flex, bite, and equilibrium) were scored as a ‘1’ if unimpaired and a ‘0’ if impaired or absent, and release condition was scored as 1 to 4 based on swimming ability, with 1 indicating strong ability and 4 poor ability. PRM = Post-release mortality AVM = at-vessel mortality. S3 Table: At-vessel measurement results from each species of shark sampled depending on at vessel condition or post-release fate. Our findings suggest that no-take regulations may be beneficial for sandbar, tiger, and bull sharks, but less effective for more susceptible species such as blacktip and spinner sharks. Total fishing mortality reached 62% for blacktip and 89% for spinner sharks, which may be under-estimates given that some soak times were shortened to focus on PRM. Blood physiology indicated that PRM was primarily associated with acidosis and increases in plasma potassium levels. Ninety percent of PRM occurred within 5 h after release and 59% within 2 h. ![]() Decision trees based on blood values predicted mortality with >67% accuracy in blacktip and spinner sharks, and >99% accuracy in sandbar sharks. ![]() PRM rates ranged from 2% and 3% PRM in tiger and sandbar sharks to 42% and 71% PRM in blacktip and spinner sharks, respectively. limbatus, N = 105), tiger (Galeocerdo cuvier, N = 52), spinner (C. Blood was sampled from the same individuals that were tagged, providing direct correlation between stress physiology and animal fate for sandbar (Carcharhinus plumbeus, N = 130), blacktip (C. We paired blood-stress physiology with animal-borne accelerometers to quantify PRM rates of sharks caught in a commercial bottom longline fishery. Post-release mortality (PRM) is particularly difficult to quantify, limiting the accuracy of stock assessments. Bycatch mortality is a major factor contributing to shark population declines. ![]()
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