Physiology of Stress Responses in Teleost Fish
thesisposted on 11.05.2016, 00:00 by Alexis M. Anderson
Fish, like most other animals, use stress response systems when confronted with negative stimuli. Stress responses are important in the case of natural negative stimuli as they enhance a fish's ability to escape by initiating a fight or flight response. Catch and release fishing heightens physiological stress responses as it prolongs stimulation and steroid secretion. Similar to mammals, exposure to large and sustained amounts of stress—and therefore cortisol release— elicits many negative physiological effects on fish. The process of caching, removing from, and returning fish to their aqueous environment by anglers presents teleosts with an unnatural, negative stimulus. The scientific community has focused on distinguishing the difference between stress responses in teleosts, determining if the stress of recreational fishing is significantly increasing cortisol production, and examining whether such stressors affect the fitness of fish populations. By reviewing literary sources from previous research on teleost stress responses, this paper examines the mechanistic response to cortisol and other stress hormones in fish. The paper also compares corticosteroid messaging mechanisms between mammals and fish with the intent of comparing physiological effects of prolonged cortisol release. Concurrently, the paper examines the effect of high levels of cortisol on reproduction and fitness of fish. Overall, we will analyze the physiological effects of elevated cortisol due to recreational fishing along with a summary of potential stress alleviation techniques for highly stressed fish populations.