A system dynamics perspective on a global fishing enterprise: The case of tuna ranching in Mexico

摘要

Tuna ranching is a value-added economic activity along the coast of Baja California in Mexico involving the live capture and transport of migrating juvenile tuna to pens located near shore, where they are fed for a period of months then harvested and shipped fresh to Japan for the high-end sushi market. It is nested within the global business of tuna fishing and processing for the fresh seafood, in particular sushi market, centered in Japan but expanding elsewhere. This is turn is nested in the entire fishery and global business of tuna. Little is known outside the industry about the functioning of Mexican tuna ranching, however it differs in important ways compared to its Australian and controversial Mediterranean competitors that indicate relative stability, most notably that it does not involve the harvest of reproducing age animals. Our analysis and exploratory modeling exercise reveals no cause for complacency however. There are several factors and issues, most of which are not the typical concerns found in popular descriptions of tuna ranching world wide, that a system dynamics model suggests examining more closely in helping determine whether Mexican ranching activities have the potential to become sustainable.