Market Interactions Between Aquaculture and the Common-Property Commercial Fishery

Market interactions between the common-property commercial fishery and (1) competitive aquaculturists and (2) a dominant-firm aquaculturist are modeled. It is found that the entry of a competitive aquaculturist increases natural fish stocks, reduces price, and increases total supply. If initially the natural fish stock is at a level below maximum sustainable yield, entry of the aquaculturist results in an increase in supply from the commercial fishery. In the second part, the aquaculturist is modeled as a dominant firm. In some situations, the aquaculturist behaves in a manner similar to the competitive case, but impacts on price, fish stock, and efficiency will not be as large. It is shown that there also exist cases where the dominant aquaculturist will desire to promote overexploitation of the natural fish stock.