Effects of short-term capture on the physiology of white sharks Carcharodon carcharias: amino acids and fatty acids

Abstract

Empirical evaluations of how overexploited marine fishes respond to capture stress (physiologically and behaviourally) have become increasingly important for informed fisheries management. These types of studies are, however, lacking for many protected species. Here, we conducted a novel study on the physiology of juvenile white sharks Carcharodon carcharias (139-325 cm fork length), a globally protected and ecologically important predator, in response to a standard fishery interaction using shark-management-alert-in-real-time (SMART) drumlines as part of a bather protection program. Specifically, we assessed the influence of short-term capture duration (average: ~30 min; range: 10-75 min) and other biological (size) and environmental (temperature) variables on blood plasma amino acids and fatty acids, which play essential roles as energy substrates as well as in maintaining physiological functions. None of the assessed amino acids or fatty acids were affected by capture duration, but some were influenced by shark size and water temperature. Our results support the notion that white shark physiology is robust to capture at short capture durations, which has important implications for the fate of released individuals.