Electronic Theses and Dissertations

Date of Award

1-1-2019

Document Type

Dissertation

Degree Name

Ph.D. in Biological Science

First Advisor

Glenn Parsons

Second Advisor

Nicole Ashpole

School

University of Mississippi

Relational Format

dissertation/thesis

Abstract

Sharks are an essential component of many marine ecosystems; however they have experienced population declines mainly attributed to overfishing and capture of sharks as bycatch. Despite sharks often being released when captured as bycatch the act of capture can result in a stress response which may cause severe physiological perturbations. Studies have investigated the physiological impacts of capture stress on elasmobranchs but most have primarily focused on the secondary stress response. I conducted a series of studies to further describe the primary stress response through quantification of adrenocorticotropic hormone (ACTH) while also investigating methods such as sedation and limiting air exposure to reduce the magnitude of the stress response to capture. Results implicated ACTH as a reliable indicator of the primary stress response in elasmobranchs which I suggest as an additional measurement to go along with the suite of physiological stress indicators that are commonly measured in elasmobranchs. I also demonstrated the severe effect of air exposure on elasmobranch physiology and suggest that fishers limit sharks to no more than five minutes of air exposure during catch-and-release fishing. Lastly I show the potential of iso-eugenol sedation at reducing levels of stress indicators. These studies have combined the disciplines of conservation and physiology in an effort to provide methods and results that can be utilized in conservation management of shark populations.

Included in

Biology Commons

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