GALIMA, MM; LOWE, CG; KELLEY, KM; California State Univ., Long Beach; California State Univ., Long Beach; California State Univ., Long Beach: Catch-and-Release Stress and its Impacts on the Endocrine Physiology of the California Sheephead, Semicossyphus pulcher
A catch-and-release policy was implemented several years ago for undersized S. pulcher with the objective of reducing impacts of fishing pressures on this economically important species. It has not yet been established, however, whether the stress associated with catching and releasing has subsequent maladaptive effects. The impacts of catch-associated stressors on the endocrine physiology of this species were therefore examined, with an emphasis on how metabolism and growth may be altered. Fish were caught offshore near Catalina Island using standard hook and line or commercial trapping. Controls (baseline) consisted of fish blood-sampled within 3 min of initial disturbance, which included catching and rapid retrieval to the surface as well as catching directly underwater while diving. Fish were subjected to the following stress-inducing protocols: 1) increasing angling fight times up to 20 min, 2) line-catching and confinement in tanks for 10 min to 30 d, 4) trap-catching with up to 5 h soak times, and 5) catching, releasing to the environment for varying periods, and then sampling of recaptured fish. In all experiments, plasma cortisol concentrations increased significantly and often dramatically in response to catch-associated experiences, in a manner commensurate with the time and intensity of the treatments. Following the elevations in cortisol were sustained increases in plasma glucose, while increases in lactate were more transitory. Plasma levels of an IGFBP were increased in stressed fish, along with alterations in IGF-I concentrations. Our data thus far indicate that captured S. pulcher experience a profound stress response with associated metabolic and growth impacts. [Support by CA Sea Grant College Program NOAA NA06RG042 2002-03, project # R/F-192 and NSF grant IBN-0115975]
