Fish in a pickle

Ocean acidification associated with climate change has surfaced as a major threat to marine ecosystems and the international fishing industry.

The world’s oceans are 30 percent more acidic than pre-industrial levels, a rate projected to double by 2100, according to the Washington Post. The ocean absorbs 30 percent of the carbon dioxide produced by fossil-fuel burning, which triggers a chemical reaction that lowers the water’s pH level. The acidification is already making it more difficult for pteropods and corals to form shells and altering the blood chemistry of some marine species, causing them to lose their ability to avoid predators.

Additionally, as oceans warm, fish of all species are likely to decrease in body size. Warmer water raises a fish’s metabolic rate, meaning it needs more food to maintain body weight. The presence of more carbon in the ocean would also play a role, as fish need more oxygen as they grow.