Wealth based fisheries management of chambo (Oreochromis spp.) fish stock of Lake Malombe in Malawi

Abstract

A study to establish bioeconomic options for economic exploitation of Chambo (Oreochromis spp.) fisheries of Lake Malombe was conducted between 2010 to 2012. Three models, logistic regression, Univariate Autoregressive Integrated Moving Average and Gordon Schaefer bioeconomic models were used in the analysis. Primary qualitative and quantitative data from fishers and consumers were collected using a pretested semi structured questionnaire. Time series data from 1976 to 2011 was generated from the Traditional Fishery Data Base at Fisheries Research Station. The logistic regression analysis showed that the goodness of fit Hosmer and Lemeshow test yielded c2 (8) of 6.924 and was insignificant at 0.05 (P = 0.214). The -2 Log Likelihood showed that the model fitted the data at an acceptable level (P = 0.001). Six predictor variables (stratum, marital status, literacy, years in fishing and daily working hours) were significant. Autoregressive Integrated Moving Average model (0, 1, 1) was selected. From the selected model, at the current exploitation rate it was forecasted that Chambo catches would decline to -1,111.80 tons in 2021 from 4,118 tons in 1976. From the Gordon Schaefer dynamic model, it is estimated that the economic rent at maximum economic yield, is MK2.148 million as compared to MK1.533 million at maximum sustainable yield. The Gordon Schaefer bioeconomic model showed that high economic rents are associated with maximum economic yield than maximum sustainable yield. Based on the bioeconomic analysis, it is recommended that Chambo fisheries be managed at maximum economic yield, which implies reducing the current fishing effort.