Ocean-based Food security threatened in a high CO2 World

A Ranking of Nations’Vulnerability to Climate Change and Ocean Acidification

Emissions from human activities are changing the ocean’s chemistry and temperature, in ways that threaten the livelihoods of those who depend on fish and seafood for all or part of their diets. The changes may reduce the amount of wild caught seafood that can be supplied by the oceans and also redistribute species, changing the locations at which seafood can be caught and creating instability for ocean-based food security, or seafood security.

This report ranks nations based on the seafood security hardships they may experience by the middle of this century due to changing ocean conditions from climate change and ocean acidification. This is done by combining each nation’s exposure to climate change and ocean acidification, its dependence on and consumption of fish and seafood and its level of adaptive capacity based on several socioeconomic factors. Country rankings are developed for risks from climate change and ocean acidification independently, as well as from both problems combined.

Fish and seafood are a primary source of protein for more than one billion of the poorest people on Earth. By 2050 the global demand for seafood is expected to rise, mainly due to an increase in population to about nine billion people. The oceans can be a large part of the solution to this global food security challenge. But at the same time, emissions of carbon dioxide and other greenhouse gases are disrupting ocean conditions and threatening the future of the essential food resources we receive from the oceans.

The Rapid Change in Ocean pH since the Industrial Revolution is Likely
the Fastest in Earth’s History (Turley, C., et al. 200616)

As a result of the increases in carbon dioxide and other greenhouse gases in the atmosphere, the oceans are warming. This is creating changes at the base of the marine food web. Because marine species and their prey are adapted to a certain temperature range, as temperatures change, their habitable ranges can change as well. Rising temperatures are shifting the locations where a given fish species can live and find food. In general, these changes are pushing many species into deeper and colder waters towards the poles and away from the tropics. Not only does this redistribution of species put the tropics at risk, but these climate induced invasions of new habitats could have serious ecological consequences, including the extinction of native species toward the poles.

The oceans absorb large amounts of carbon dioxide emissions each day. As a result, their pH has declined by 30 percent since the Industrial Revolution. This rapid change in ocean chemistry, called ocean acidification, is already threatening habitats like coral reefs, and the future of shellfish like oysters, clams and mussels is also in jeopardy. This means that nations that rely heavily on threatened types of fisheries as a primary food source could be hit hardest.

Soure and further information: Oceana.org – Ocean-based Food security threatened in a high – CO2 World

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