Fisheries management under common pool and territorial use rights regimes


Fish stocks in developing countries are typically managed either as common pool resources by a number of fishing communities or each community claims territorial use right over a fraction of a management area. Due to extraction externalities, each of these two regimes relative to a situation where a social planner manages the entire fishery results in economically inefficient outcome. This research seeks to obtain expressions for a feasible tax on cost of harvest (as opposed to ad valorem tax) that could generate first best outcomes in static and dynamic settings. The tax rate will be computed for communally owned fishery using data on artisanal fishing in Ghana. Furthermore in the absence of such a tax an expression will be developed based on the relationship between the size of the carrying capacity of the fish stock per fishing community and the number of communities involved in harvesting the stock to determine which regime is better than the other.  

Using Anchovies to Bait Tuna in a Developing country


Tropical tunas are characterized by relatively small to medium size, rapid growth and early age at maturity, low spawning duration and short life span. The three major tuna species of economic value include Bigeye, Skipjack, and Yellowfin tuna. While skipjack spawns opportunistically in vast sectors of the ocean throughout the year beginning from its first year of life, yellowfin and bigeye are less gregarious. As a result, the population of skipjack is viable but catches of yellowfin and bigeye tunas in the Atlantic oceans are presently close to or above the maximum sustainable yield. It is estimated that 40 percent of maximum sustainable yield of tuna within the eastern Atlantic is in Ghanaian waters. The law governing commercial tuna fishing does not set any catch nor catch-size limit. These three species are carnivorous species preying on other fishes and therefore belong to the same functional group. In addition, the three species are fished by two main boats: bait-boats and purse seiners. The bait-boats use anchovies as baits leading to fast depletion of anchovy stocks targeted by artisanal fishers. This project aims at modeling the conflict between artisanal fishers who fish anchovies and tuna vessels that use anchovies as baits; and derive optimal economic incentives necessary to maximize economic surplus.