5 10 15 20 25 30 35 40 45 50 Sensitivity (% animal protein from seafood)
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8
Exposure (g decrease per capita for 1000 tonne shock)
Northern Europe Western Europe Southern Europe Eastern Europe Central Western Asia South Central Asia Eastern Asia Southeast Asia Oceania MENA West Africa Central Africa Eastern Africa Southern Africa South America Caribbean Atlantic Central America North America
The figure on the right shows how each region along the vertical axis is exposed to shocks originating from each other region along the horizontal axis. Exposure is measured by the percentage of the initial shock in the latter region ending up in the former region. Central and West Africa, Southeast and Eastern Asia, and Southern and Western Europe exhibit the highest exposures.
Vulnerability to Shocks in the Global Seafood Trade Network
Jessica A. Gephart (University of Virginia, Charlottesville, USA)
Elena Rovenskaya (Advanced Systems Analysis Program, IIASA; Moscow State University, Russia) Ulf Dieckmann (Evolution and Ecology Program, IIASA)
Michael L. Pace (University of Virginia, Charlottesville, USA)
Åke Brännström (Evolution and Ecology Program, IIASA; Umeå University, Sweden)
We introduce a model of shock propagation and distribution among regions on a network of historical bilateral seafood trade data from UN Comtrade using 205 reporting territories grouped into 18 regions.
Shocks originate from decreased exports from one region, reducing the flows to importing regions.
Regions with reduced imports either reduce their own exports, thus passing on a fraction of the shock, or reduce their domestic fish
supply, thus absorbing the shock locally. For increased realism, we account for a larger
willingness to pay when supplies drop in regions with higher GDP per capita.
Approach
We analyze how seafood trade flows are redistributed under a range of shock
scenarios and assess the food-security implications by comparing changes in regional fish supplies to indices of each region’s nutritional fish dependency.
Objective
Result 1: Shock exposures are highly heterogeneous
The figure on the right shows how increasing the influence of GDP per capita on the willingness of affluent regions to pay higher prices when faced with shortfalls in supply increases the proportion of shocks ending up in West and Southern Africa.
Result 2: Poor regions’ exposures are exacerbated by rich regions’ willingness to pay
0 0.01 0.05 0.1 0.5 1 5 10 0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Proportion of shock in region
Influence of GDP
Northern Europe Western Europe Southern Europe Eastern Europe
Central Western Asia South Central Asia Eastern Asia
Southeast Asia Oceania
MENA West Africa Central Africa Eastern Africa Southern Africa South America Caribbean Atlantic Central America North America
Middle East and North Africa
Percent shock in region
North America Central America Caribbean & Atlantic Islds South America Southern Africa Eastern Africa Central Africa West Africa Middle East & North Africa Oceania Southeast Asia Eastern Asia South-Central Asia Central-Western Asia Eastern Europe Southern Europe Western Europe Northern Europe
North America Central America Caribbean & Atlantic Islds South America Southern Africa Eastern Africa Central Africa West Africa Middle East & North Africa Oceania Southeast Asia Eastern Asia South-Central Asia Central-Western Asia Eastern Europe Southern Europe Western Europe Northern Europe
Result 3: West and Central Africa are most vulnerable
The figure on the right shows the relative vulnerabilities of regions by comparing their exposures and sensitivities. Exposure is measured by a region’s per capita decrease in
seafood intake resulting from a 1000-tonne shortfall in supply, while sensitivity is measured by a region’s percentage of animal-protein nutrition derived from fish. With relatively high
exposures, high sensitivities, and low adaptive capacities, we find West and Central Africa to be the regions most vulnerable to shocks in the global seafood trade network.
