Bio-economics of common resource over exploitation. Case of Lake Malombe Chambo (Oreochromis Sp. cichlidae) fishery in Malawi

Abstract

Increased attention has been paid over recent years to the Over exploitation of small-scale fishery resources. This paper offers a simple bio-economic model of fishery exploitation orientated towards both Lake Malombe Chambo (Oreochromis sp.) and the Whole Lake Malombe Fishery. The catching of Chambo in Lake Malombe has historically been important to Malawi Fisheries, and the changes that have taken place in the Fishery have had major social and economic consequences on communities around the Lake. Bioeconomic exploration of this fishery has been based on the catch, effort and price data from 1976 to 1999. It has been demonstrated here that, Chambo. Fishery provides a unique illustration of the economic and biological effects of technological (gear type) change in situations where access to the natural resource remains virtually unrestricted (open access). The components of the model are explained with reference to their guiding economic (Maximum Economic Yield) and biological (Maximum Sustainable Yield) reference points. And it is estimated in the study that if yield of Chambo falls below 6900 tons and 14 621 tons for the Whole fishery, then the rate at which the population regenerates itself falls below the rate of extraction. The paper also draws the problem of effort over capacity as the current capacity exceeds, by a wide margin, the capacity that would be required to harvest a sustained yield. In addition to the over capacity is the problem of selectivity in the gear types. Such over capacity and non-selectivity in fishing gear makes control of catch and efforts difficult and threatens the fishery.