Identifier

etd-05232007-214956

Degree

Doctor of Philosophy (PhD)

Department

Renewable Natural Resources

Document Type

Dissertation

Abstract

This dissertation addresses applying industrial park concepts to the development of aquaculture parks in public waters specifically for off-bottom triploid Easter oyster, Crassostrea virginica, culture. The objectives are to identify the permitting process, relevant agencies, and legislation needed to facilitate development of aquaculture parks in the Gulf of Mexico states, and test and analyze off-bottom oyster culture for commercial production of triploid oysters. Off-bottom culture can increase oyster production, but fouling organisms can reduce growth and survival rates. The Adjustable Longline System (ALS), commercially used in Australia, allows oyster bags to be suspended in the water column and positioned for aerial drying to deter fouling. This study evaluates means of controlling fouling organisms for off-bottom culture of diploid oysters by measuring 1) growth rate, 2) survival rate, and 3) fouling rates. This study shows that routine aerial exposure reduces the amount of fouling organisms without significantly affecting growth or survival. The oysters in all treatments reached market-size in twelve months and had survival rates greater than 80%. Advances in oyster genetics research are creating superior candidates for culture and needs to be coupled with advanced grow-out methods to reach full potential. Triploid oyster culture is a viable alternative to natural oyster production but requires investment in seed. This study analyzed the capital, operating costs, and break-even prices of a 0.40-hectare ALS for triploid oyster culture. The analysis assumes that seed is purchased from a hatchery and that the culturist harvests triploid oysters during the months when on-bottom oysters have a lower meat yield. The break-even costs are determined for a 100-count box of oysters. Once importation and permitting costs are determined, areas of the budget can then be adjusted to reduce the break-even price. This will include such factors as domestic system components, labor hours, or stocking density. The results will determine if off-bottom culture of triploid oysters is a good investment for the Louisiana oyster industry. In addition, an operational plan was also prepared for the ALS to meet the International Shellfish Sanitation Council requirements for shellfish culture facilities.

Date

2007

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Dr. John Supan

DOI

10.31390/gradschool_dissertations.2924

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