BIO-ECONOMIC MODELING OF CONTAMINATED BLUEFIN TUNA AND ATLANTIC MACKEREL FISHERIES DYNAMICS

Following the discovery of acute mercury toxicity from seafood consumption in the 1950s and subsequent research into mercury in the environment, scientists and managers now recognize the health threats of mercury poisoning from seafood consumption, especially in fetuses, infants, and children. Unfortunately, consumers remain confused or uneducated about species-specific mercury concentrations, thus perpetuating the risks associated with contaminated seafood.

This study models the bio-economic dynamics of a system involving two species consumed by humans: a highly mercury-contaminated predator, bluefin tuna, and a tuna prey fish with low levels of contamination, Atlantic mackerel. Model scenarios evaluate varying levels of mercury pollution, consumer aversion to mercury, and fishes’ biological resistance to mercury poisoning to determine optimal harvest rates and population sizes for both species. The results demonstrate that while the mackerel fishery remains largely unaffected by the influence of mercury, optimal harvest and population of tuna depend greatly upon their biological resistance to mercury and consumers’ aversion to purchasing mercury-contaminated fish. When resistance to mercury is low, both tuna population and harvest decrease. When consumer aversion is high, harvest decreases and population increases. Increased mercury pollution exacerbates both effects.

Due to lack of previous such studies and the paucity of empirical data, this research is both exploratory and qualitative in nature. Effective fisheries conservation and management requires understanding the strength of both fish resistance and consumer aversion to mercury. Future research should address the lack of empirical data, both biological and economic, as well as refine the above model in order to assist managers in appropriate consumer education and setting fisheries management goals that couple sustainability and public health.