Impacts of Nile Perch (Lates niloticus) overfishing on the technical efficiency of fishers in the Tanzania portion of Lake Victoria

The present study employed the Data Envelopment Analysis (DEA) and Propensity Score Matching (PSM) techniques to assess the impacts of Nile perch overfishing on the technical efficiency of fishers, based on a survey of 268 fishers across ten landing sites in the Tanzanian portion of Lake Victoria. The DEA results indicated overall that Nile perch fishers exhibited an average technical efficiency of 30%, indicating a high level of inefficiency. There were no statistically significant differences in the technical efficiencies within the range of 0%–10% and 21%–30% for Nile perch fishers who were overfishing and those who were not overfishing, attributed to the fisher's mobility across the lake. Further, the mode of propulsion and being a member of a fishery organization were found to be statistically significant factors influencing the inefficiency of Nile perch fishers. In addition, results from the Probit estimates of the PSM indicated that being a member of a fishery organization, the quantity of Nile perch harvested per trip, the age of a fishing vessel (boat), the gillnet mesh size and the cost of fishing inputs had statistically significant effects influencing the probability of Nile perch overfishing. However, further results indicated Nile perch overfishing did not have a statistically significant impact on the technical efficiency of fishers. Thus, it is recommended that there is a need to monitor and formalize fisher's mobility as one of the alternatives for co-management of the lake. Overfishing could be controlled without necessarily affecting the technical efficiency of Nile perch fishers through training and access to proper fishing gears.