Recreational fishing fight times are not correlated with physiological status of blue sharks (Prionace glauca) in the Northwestern Atlantic

Shea, Brendan D.; Coulter, Sydney K.; Dooling, Kelly E.; Isihara, Hana L.; Roth, Jessica C.; Sudal, Elliot; Donovan, Donald J.; Hoopes, Lisa A.; Dove, Alistair D.M.; Cooke, Steven J.; Gallagher, Austin J.

Abstract

Sharks, like other fish, react to capture and handling stress with more exaggerated physiological responses than most other vertebrates, and the potential consequences of their capture include both sub-lethal and lethal effects. Blue sharks, Prionace glauca, are one of the most heavily exploited species of sharks in the world, both in commercial and recreational fisheries, and while the capture response of blue sharks in commercial fisheries has been comparably well-studied, there is a relative lack of information regarding the influence of handling and capture on the species in the recreational setting. Our analysis of blood-based biomarkers, such as glucose, lactate, pH, and plasma electrolytes, sampled from twenty blue sharks captured in the recreational fishery suggests that over the short hook times (time on the line) characteristic of the fishery, blue sharks do not fight to the point of blood acidosis and are likely able to withstand capture and handling in a catch-and-release setting. We did note an inverse relationship between shark total length and blood glucose levels, suggesting the possibility that smaller individuals may be more susceptible to capture stress, but this variation may also reflect other metabolic factors or an ontogenetic shift in diet. We discuss these findings within the context of the recreational fishery, including priorities for angler education.