Recreational fishing of sharks in the Great Barrier Reef Marine Park: catch and release stress

DE FARIA, F.; SIMPFENDORFER, C.; SUTTON, S.; TOBIN, R.; AWRUCH C. A.

Congreso; Sharks International Conference; 2010

James Cook University

Recreational fishing is a major activity in the Great Barrier Reef (GBR) and yet we do not know much about their catch. Collecting and aggregating catch and effort data relating to the recreational fishing sector is difficult because, in the majority of cases, recreational fishers do not have to report their activities to a management agency. Although individual fishers may have limited impact, recreational fishing can have a large effect on shark populations due to the large number of people who participate in the fishery.  Many studies have addressed the potential impacts of fishing on shark populations but not many studies have focused on the GBRMP, especially regarding recreational catch. Preliminary studies on recreational fishing of sharks in the GBR found that recreational fishers do not usually target sharks and most sharks caught are released. High release rates were also shown by state-wide surveys done by QPIF in 2002 and 2005. The results suggest that post release mortality have great potential to affect shark populations of the GBRMP considering the amount of sharks released. This study aims to use blood lactate levels as an indicator of stress in sharks caught by recreational fishers and establish a relationship between stress levels and different catch and release practices. Results will provide recommendations to fishers and managers about how physiological effects of catch and release can be reduced and how handling and release practices can be improved.