Seafood Globalization: Implications for Vulnerability and Resilience

Seafood is among the most highly traded food commodities and plays an important role in global nutrition. Further, its production is closely tied to the ecosystems that support harvests and the natural resources (e.g. clean water) that allow aquaculture. Together intensive trade and tight linkages between seafood production and the environment distances consumers from the environmental impacts of seafood production and exposes seafood production to environmental change and variability. The goal of this dissertation is to assess the globalization of seafood and the resulting implications for vulnerability and resilience.
The historical structure and evolution of the seafood trade network was characterized using network analysis. This analysis revealed an increase in trade partnerships by 65% and an increase in traded quantity by 58% over the period 1994 to 2012. Additionally, the trade patterns in the network indicate: increased influence of Thailand and China, strengthened intraregional trade, and increased exports from South America and Asia.
This increasing globalization can allow countries to buffer against local or regional shocks that might cause sharp declines in seafood supply but also exposes nations to external shocks transmitted through the trade network. Central and West Africa were found to be the most vulnerable to such shocks in a forward shock-propagation model. Historical cases of shocks to seafood production are identified using a statistical shock identification approach with a complementary qualitative approach. The identified cases indicate that there is no trend in the frequency or magnitude of shocks in the aggregated production or in the magnitude of shocks in the species production, but there is an increase in the frequency of shocks in the species time series. Further, the highest number of shocks occurred in Europe, Africa, and Asia, which also tended to have shocks of larger magnitude. Shock rates and magnitudes were similar among species groups, but shocks occurred more frequently in aquaculture systems than capture systems.
In addition to adapting to changes in domestic seafood production through trade, countries can alter production of other food sources in the long run. This ability is assessed by comparing the water cost for countries to replace marine protein with terrestrial foods using available water resources. Replacing marine with terrestrial protein would require an additional 350 km3y-1 of water globally. This quantity can alternatively be viewed as a current water savings of 4.6%. The importance of these freshwater savings is highly uneven around the globe, with savings ranging from as little as 0 to as much as 50%. For countries with a high use of marine protein and limited water resources, seafood is an important component of joint food-water security.
Seafood trade has increased globally in recent decades. This dissertation quantifies the network structure and degree of globalization for seafood. This globalization provides both opportunities and risks in terms of the vulnerability and resilience of the food system. Within this context of increasing globalization, this dissertation presents three new perspectives on the vulnerability and resilience of the global seafood system through modeled exposure to shocks in the network, historical impacts of shocks on trade and seafood supply, and the ability of countries to replace marine foods with available resources.