Telecouplings in Atlantic cod-The role of global trade and climate change

Seafood trade is a global business, where catches, processing, and consumption are increasingly separated. An increasingly integrated global market creates telecouplings, i.e. connections between fish stocks that are ecologically separated. These telecouplings may spread the impact of vulnerabilities, such as climate change, between unconnected fisheries. The effect of climate change on fisheries is often analyzed on a fish stock basis, which may overlook the spread of these vulnerabilities. Atlantic cod (Gadus morhua) stocks, an iconic fish species, are no exception. Depending on the geographical location, stocks have been impacted differently by climate change, with North-East Arctic (NEA) cod, the stock in the Barents Sea, reaching record high biomass levels and other stocks being extremely depleted. Here, we investigate how these dynamics occurring in the ecological system affect global trade of cod. We find that the global export is fully dominated by NEA cod catches. Applying Structural Equation Modelling, we discover that the high biomass level of NEA cod has positive effects on catches and exports and leads to lower global market prices. However, zooming in on individual stocks and the countries exploiting them using correlation networks, we find heterogeneous responses of other countries, where catches for some stocks increase and others decrease in response to lower global prices. Our results highlight how changes on one fishery may have important repercussion on stocks in different ecosystems, as well as on societies reliant on them.