Date of Award

1990

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Oceanography and Coastal Sciences

First Advisor

Richard Condrey

Abstract

A three year study, 1982-85, of eight oystermen bedding on 19 leases in lower Barataria Bay was designed to determine lease production, fuel, labor and energy inputs and the expenses to operate. The data was then incorporated into a bioeconomic model of the lower Bay. Commercial yield ratios (sacks harvested:sacks bedded) per lease ranged from 0.03$-$1.68:1. The two lowest lease yields were the result of vandalism and poaching, respectively. A multiple linear equation developed from the data predicts that as salinity and water temperature increase, lease yields decrease. Utilization of the Bay's bedding leases are dependent on seed obtained from the public grounds. The lower-Bay oystermen harvested 87% of their seed from the public grounds. Vessels consumed an average of 294 liters of diesel per day while bedding and 90 liters per day while harvesting for market. An average of 2.23 liters of diesel was consumed per sack sold (bed + harvest fuel). Oystermen spent an average of 69 man-days of labor bedding seed (based on a crew of 3) and 124 man-days of labor harvesting for market. An average of 76 sacks were harvested per day of labor (bed + harvest labor). The energy efficiency ratio (kcal oyster meat produced/kcal input) equaled 0.11:1. Average daily expenses to operate were 18 percent higher while bedding than while harvesting for sale. Total variable expenses (bed + harvest) were separated into each expense category's contribution: labor for two deckhands (59%), general maintenance of vessel and engine (18%), vessel fuel, oil and grease (14%), galley supplies and food (8%), and butane and ice (1%). An oysterman may see a net return of 75% above annual operating expenses (variable + fixed), before captain (owner) and vessel shares are taken out. A profit can occur only when there are sufficient quantities of seed to bed. Application of a bioeconomic model indicates that if lower-Bay oystermen wait until October to bed, potential lease yield increases. In addition, if an oysterman beds in upper Barataria Bay, where historical salinities are lower, lease production may increase significantly over bedding in the lower Bay.

Pages

169

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