Production Technology and Natural Resource Sustainability: the Case of Kenya's Lake Victoria Fisheries. Paper to be presented at World Congress of Environmental and Resource Economists, Venice, Italy, June 25-27, 1998.

The nature of production technology characterizing any fishery has serious implications for its management and, hence, sustainable exploitation. This paper specifies and estimates production functions for Kenya's Lake Victoria fisheries in order to characterize the technology used in their exploitation. Regulations for these fisheries were drawn up without sound empirical information about this important issue. The paper, in addition, assesses the relative sustainability implications of different fishing technologies by comparing them on the basis of their selectivity and their harvests of juvenile fish. The determinants of the amounts of juvenile fish harvested by fishing units engaged in the exploitation of these fisheries are also investigated as are the motivations behind the choice, by fishing firms, of technologies that are obviously pernicious to their only source of livelihood. The Cobb-Douglas specification of the production functions is used for comparison across fisheries. The production process differs significantly from fishery to fishery and from individual fisheries to the aggregate fishery, indicating the inappropriateness of managing the fisheries as a single fishery. There are decreasing returns to scale in the set net fishery only, the rest being characterized by increasing returns to scale. Fishing time and net mesh size emerge as the ‘key’ dimensions of effort. Fishing time is currently unregulated, yet it offers the largest scope in reducing pressure on the resources. Labour use is excessive and inefficient in two fisheries. Vessel size, vessel propulsion means, type and size of gear, spatial and seasonal stock variations, and inshore versus offshore fishing are other important factors in the fishery production functions. Trawling, mosquito seining, beach seining and the use of set nets are found to pose the greatest risk to the sustainability of the fisheries whereas the gillnet, longline, traps and mosquito seine with lights technologies are appropriate. Important determinants of juvenile fish harvest levels are the type of gear, net mesh size, level of education, owner-head effects, inshore fishing, fishing time and size of crew. Fishermen are rational in their choice of inappropriate technology. Not only are these relatively cheaper but most fishermen are faced with acute capital constraints. Being cheaper and illegal inappropriate technologies are, in addition, associated with less risk of theft. Moreover, their profitability is comparable to that of appropriate technologies, there being a market for the immature fish they harvest. The fisheries are open access, providing no incentives, thus, for conservation efforts. Management of these fisheries will only succeed through the creation of economic incentives to induce behavioural change.