Date of Award

Summer 8-5-2019

Degree Type

Dissertation

Degree Name

Ph.D.

Degree Program

Engineering and Applied Science

Department

Earth and Environmental Sciences

Major Professor

Dr. Martin O'Connell

Abstract

In the southeastern United States, skimmer trawls, pusher-head trawls, wing nets, and small try nets (headrope length less than 12-ft (3.66-m)) are exempt from using a turtle excluder device (TED) and instead must adhere to tow time restrictions as a mode to mitigate sea turtle bycatch. However, observer and stranding data indicate that these tow times may often be exceeded and result in mortality of sea turtles. The National Marine Fisheries Service (NMFS) published a notice of proposed rulemaking in December 2016 to extend TED requirements to other trawl types, however there has been limited development of specialized TEDs for these smaller trawls. In anticipation of a regulatory change, we developed and identified multiple versions of a top-opening TED with a minimum width of 28-in (71-cm) and height of 24-in (61-cm) as the best option for small trawl gears. Prototypes were initially equipped within small try nets and tested for gear performance and sea turtle exclusion in Panama City, Florida. The final designs were then tested for target shrimp retention, bycatch reduction, and general usability of TEDs in the commercial fisheries. A paired comparison test was conducted in 8-ft (2.44-m) and 10-ft (3.05-m) try nets aboard the NMFS R/V Caretta, three commercial skimmer trawls in vesselsFarfantepenaeus duorarum) fishery. There was a general reduction of shrimp and bycatch averaging from a minimum loss of 3.31% in the Miami wing net fishery (FV FL-01) to 22.07% in the skimmer trawl fishery (FV LA-01). This dissertation research indicates that TEDs can function properly in small trawl types, however additional studies are recommended to minimize the shrimp loss and improve the overall TED effectiveness specific to each fishery and trawl type evaluated.

Rights

The University of New Orleans and its agents retain the non-exclusive license to archive and make accessible this dissertation or thesis in whole or in part in all forms of media, now or hereafter known. The author retains all other ownership rights to the copyright of the thesis or dissertation.

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