The physiological response of the Caribbean reef shark (Carcharhinus perezi) to longline capture

• Published in: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology Molecular & integrative physiology, 2012-06, Vol.162 (2), p.94-100
• Main Authors: Brooks, Edward J., Mandelman, John W., Sloman, Katherine A., Liss, Stephanie, Danylchuk, Andy J., Cooke, Steven J., Skomal, Gregory B., Philipp, David P., Sims, David W., Suski, Cory D.
• Format: Article
• Language: English
• Subjects: Animals; blood; Blood chemistry; blood pH; calcium; Capture stress; Carcharhinus; Carcharhinus perezi; Caribbean reef shark; Caribbean Region; Elasmobranchii; fisheries management; glucose; lactic acid; Longline; Marine; Non-linear stress response; Parabolic stress response; potassium; Restraint, Physical; sharks; Sharks - blood; Sharks - physiology; Species Specificity; stress response; Stress, Physiological; sublethal effects; Survivorship; timers
• ISSN: 1095-6433; 1531-4332
• DOI: 10.1016/j.cbpa.2011.04.012

Longline fishing is the most common elasmobranch capture method around the world, yet the physiological consequences of this technique are poorly understood. To quantify the sub-lethal effects of longline capture in the commonly exploited Caribbean reef shark (Carcharhinus perezi), 37 individuals were captured using standard, mid-water longlines. Hook timers provided hooking duration to the nearest minute. Once sharks were landed, blood samples were taken and used to measure a suite of physiological parameters. Control data were obtained by sampling an additional three unrestrained Caribbean reef sharks underwater at an established shark feeding site. The greatest level of physiological disruption occurred after 120–180min of hooking, whereas sharks exposed to minimal and maximal hook durations exhibited the least disturbed blood chemistry. Significant relationships were established between hooking duration and blood pH, pCO2, lactate, glucose, plasma calcium and plasma potassium. Longline capture appears more benign than other methods assessed to date, causing a shift in the stress response from acute at the onset of capture to a sub-acute regime as the capture event progresses, apparently facilitating a degree of physiological recovery. Continued investigation into the physiological response of elasmobranchs to longline capture is vital for the effective management of such fisheries.