Hotter, More Acidic Ocean Threatens Food Security

This post was written by Matt Huelsenbeck, a marine scientist at Oceana, the largest international advocacy group working solely to protect the world's oceans. To learn more, please visit

Fish and seafood is currently a primary source of protein for more than a billion of the poorest people in the world, but carbon dioxide emissions are causing the oceans to warm and become more acidic, threatening fisheries and the people who depend on them. According to a new report by Oceana, the areas most at risk from the harmful impacts of acidification and climate change are poor coastal and small island nations, regions that depend more heavily on seafood for protein.

The oceans are becoming more acidic from the absorption of massive amounts of carbon dioxide emissions. The oceans are now 30% more acidic than before the Industrial Revolution and the rate of change in the ocean's chemistry is likely the fastest in Earth's history. This rapid change in acidity is threatening important habitats such as coral reefs and the future of shellfish like oysters, clams and mussels.

Additionally, rising ocean temperatures are pushing many fish species into deeper and colder waters, in a general trend toward the poles and away from the tropics. Nations that lack large industrialized fishing fleets will be unlikely to chase these migrating fish around the world, and the poorest small scale fishermen will be hit hardest.

Many coastal and island developing nations, such as Togo, the Cook Islands, Kiribati, Madagascar and Thailand depend more heavily on seafood for protein and could suffer the greatest hardships because they have fewer resources to replace what is lost from the sea. For many developing countries, seafood is often the cheapest and most readily available source of protein, losing this resource could have serious impacts on livelihoods and food security.

The only way to address global ocean acidification and the primary path to ending climate change is by dramatically reducing carbon dioxide emissions. One of the first logical steps in this process should be to phase out all fossil fuel subsidies.

Some local measures may help make marine resources more resilient to the impacts of climate change and ocean acidification such as stopping overfishing and limiting local pollution, but reducing carbon dioxide emissions is essential to make sure the oceans stay vibrant and productive for future generations.