A BIOECONOMIC ANALYSIS OF THE NORTHERN ANCHOVY

Abstract

A simple bioeconomic model was specified and estimated for the central subpopulation of the northern anchovy (Engraulis mordax). Net population growth was described by a power function and harvest by the U. S. reduction fleet was modelled by an exponential production function. When incorporated into a bioeconomic model they allowed the derivation of two explicit functions, Y = Ö(X) and Y = Ø(X) which could be used to depict the bioeconomic optimum. The roots of Ö(X) have important economic interpretations and can be used to characterize the economic status of the fishery. The positively-sloped segment of the Ö(X) curve may be used as an approximately-optimal adaptive management policy. For the set of bioeconomic parameters circa 1990, anchovy biomass would need to increase to about 1 million metric tons before arousing the economic interest of the wetfish fleet. Alternatively, a price/cost ratio of 0.6 or more would imply positive net revenues at a biomass of 350,000 metric tons. The current price/cost ratio may be as low as 0.1 and the current estimate of biomass is about 300,000 metric tons. Thus, unless there is a dramatic increase in the demand for oil and fish meal or a spectacular increase in biomass, it seems unlikely that there will be a resurgence in the reduction fishery for anchovy in the near future.