Physiological and Behavioral Effects of Angling Stress on Two Important Gamefish in Southern California
Chris Lowe, Ph.D., California State University Long Beach
Project Overview:
Kelp bass and barred sand bass have historically supported two of the largest recreational fisheries in southern California for over the last 60 years, providing valuable economic, social, and ecological functions in coastal communities. However, gamefish are experiencing increasing fishing pressures as the number of anglers increases every year with the rapidly growing human population. Increased fishing pressures, occurring simultaneously with poor environmental conditions for recruitment, have likely been driving the declines in stock abundances observed for kelp bass and barred sand bass over the last two decades.
Annual kelp bass landings have declined 70% from 1980’s levels, and annual barred sand bass landings have declined 85% since 2001 alone. Therefore, finding methods to reduce stress associated with mandatory catch & release is essential for enhancing sustainability of the recreational fishery and for providing adequate management strategies.
OBJECTIVES:
- Evaluate the physiological and behavioral responses of kelp bass and barred sand bass to angling and handling stressors
- Quantify the rates of post-release recovery to aid fisheries managers in estimating long-term effects of fishing activity
- Educate anglers on best fishing practices that minimize stress on fish during catch and release
Results from this study will benefit the recreational fishing community by providing anglers with evidence of how certain angling and handling practices may significantly affect fish health and recovery, thus, empowering anglers to positively influence the fate of these fisheries. By offering anglers the knowledge and tools to engage in less deleterious fishing practices, the overall impacts of angling activity can be mitigated and the long-term sustainability of these recreational opportunities protected.
Additionally, by evaluating the effects of catch and release on individual fish, managers can more accurately predict the long-term effects of angling activity on the entire stock and modify fishing regulations to enhance stock recovery and growth. Ultimately, the knowledge gained through this research will improve fishery sustainability by aiding mangers in implementing effective long-term regulations and educating anglers on fishing practices that reduce their impact on these important gamefish populations.
Read the summary project proposal
2018 Research Update:
Thus far, the study has obtained behavioral tracking data for 13 fish, determined basal (control) cortisol, glucose and lactate levels in fish, determined maximum cortisol levels, and determined the rapid rate of recovery of the fish from catch and release stress. Preliminary results seem to indicate that release into the fish’s natural habitat and possibly even the time of day of the catch and release play a role in the rate of recovery. A manuscript is in preparation and two presentations have been given. These data are being shared and will be used to identify best fishing practices for recreational anglers to minimize negative impacts on these valuable fisheries.
Left: Caught a big one!; Right: Taking a blood sample
Left: Deploying a tracking bouy; Right: Volunteers help with catch and release fishing
- USC Sea Grant
- 3454 Trousdale Pkwy, CAS 200
- Los Angeles, CA 90089-0373
- (213) 740 - 1961
- seagrant@usc.edu
