Undergraduate Honors Theses

Thesis Defended

Spring 2011

Document Type

Thesis

Department

Environmental Studies

First Advisor

Dan Sturgis

Second Advisor

Alexander Cruz

Third Advisor

Dale Miller

Abstract

To date, there is a widespread decline in Chondrichthyan species (sharks, rays, and chimeras) in virtually every ocean. Due largely to unregulated fishing for their highly valued fins, approximately 75 to 100 million sharks are killed and ―finned‖ every year. Millions more fall victim to accidental bycatch from non-target commercial fisheries. Though not as heavily researched, the destruction of vital nursery areas and habitat has undoubtedly served as another factor causing many species to become threatened. Management efforts to preserve these species has been lacking due to the historical low-value of the species, but is further made more difficult due to their K-selected life history and the transboundry migratory routes undergone by many different species. Proper management and scientific efforts are further hindered in developing nations where shark catches tend to be under-reported, unidentified, or not reported at all. Some specific shark species are apex predators and ―keystone‖ species and as such, over-fishing of select species may cause adverse trophic interactions which may harm other commercially important fisheries. Some faster growing, more fecund species may be able to sustain populations under current fishing pressures; however, this does not apply to many deep sea, pelagic, and coastal species. As more scientific research and management efforts are desperately needed to preserve current stocks, some conservation efforts seem to be effective at reducing shark mortality. The implementation of marine reserves appears to show large promise in protecting both target and non-target species. Current research on bycatch reduction devices may limit mortality in non-target fisheries; while political efforts such as the U.S. Shark conservation Act of 2011 may help to reduce mortality as a result of "finning".

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