MANAGEMENT STRATEGIES OF STOCKING DENSITY AND LENGTH OF CULTURE PERIOD FOR THE CATARINA SCALLOP ARGOPECTEN CIRCULARIS (SOWERBY) - A BIOECONOMIC APPROACH

A bioeconomic analysis was made to help define management strategies o f stocking density and length of culture period for the scallop Argope cten circularis (Sowerby). The internal rate of return (IRR) was used as a criterion for maximizing profit at different plant sizes, Analyse s were made at low and high stocking rates. For plant sizes larger tha n 1.2 million juveniles, using high densities improved the IRR but had higher risk because of critical inconsistencies in survival. High sen sitivity of the IRR to stocking density and culture period required th ese variables to be strictly controlled to maximize the IRR. The sensi tivity of IRR to changes of +/- 5% in the values of the parameters of the bioeconomic model was found to be significantly different (P < 0.0 1) between plant sizes. The IRR was particularly sensitive to the maxi mum size attainable by the organisms, mortality sale price and cost of equipment for grow-out. The importance of considering uncertainty in the parameter estimates when projecting a pilot plant is addressed.