Identifier

etd-04182014-234551

Degree

Master of Science (MS)

Department

Renewable Natural Resources

Document Type

Thesis

Abstract

The blue crab (Callinectes sapidus) is a commercially, recreationally, and ecologically important species in Louisiana coastal waters. Louisiana landings account for more than 80% of Gulf of Mexico hard crab landings. In 2012, over 24 thousand metric tons of blue crab were landed in Louisiana with an economic value over $52 million. The blue crab fishery in the northern Gulf of Mexico relies heavily on Atlantic menhaden (Brevoortia tyrannus) for bait, which is a species with stock concerns resulting in approximately a 20% decrease in total allowable catch beginning in 2013. Decreased landings results in increased cost of B. tyrannus for industrial and bait uses, demonstrating a need for new cost-effective alternative bait. Large amounts of waste are produced from processing over 40 thousand metric tons of penaeid shrimp annually landed in Louisiana. Shrimp carapace accounts for approximately ¨ö to ¨ø of the total biomass and can be used an attractant in alternative bait. The objectives of this study are: 1) determine a feasible attractant utilizing seafood processing waste; 2) determine if alternative bait soak time, diffusion, and catch will perform similar to B. tyrannus; and 3) Determine fishermen opinions and preferences for an alternative bait. Crabs responded favorably to bait created with shrimp waste as the attractant in laboratory choice bioassays. Field trials in three temperature regimes demonstrate soak time of alternative bait is comparable to the current natural bait used by the industry. Additionally, the alternative bait diffuses proteins, which stimulate feeding in crabs, at levels similar to or higher than natural bait. Paired-trap field trails demonstrated alternative bait produces catch rates comparable to natural bait; shrimp alginate accounted for 41% of total catch. Additionally, reduced rates of bycatch were seen in traps baited with alternative bait. Interviews conducted with commercial fishermen indicate the industry is willing to use alternative bait. Current results show a bait created with a waste product as an attractant is feasible. Alternative bait would benefit blue crab fishermen, B. tyrannus stocks by reducing fishing pressure, and processors by creating a value added product.

Date

2014

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Anderson, Julie A.

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