The world's oceans are in trouble. Every day, 22 million tons of carbon dioxide from factories, cars, power plants and other human sources are absorbed by the world's oceans.

The result? A frightening phenomenon that's making seawater more acidic, spelling disaster for many marine animals, from plankton and coral up the food chain to sea stars, salmon, sea otters, whales — and ultimately people, who rely on oceans for food.

The oceans have become 30 percent more acidic because of the carbon pollution we're pumping into the atmosphere. We're already seeing the effects as coral reefs collapse, oyster beds disappear and tiny creatures that are important food sources get smaller and weaker.


Shell-forming animals like corals, crabs, oysters and urchins are getting hit first because ocean acidification robs seawater of the compounds these creatures need to build shells and skeletons, impairing their development and, ultimately, their survival. If shellfish populations collapse, the animals that eat them will also suffer, with ripple effects throughout the ocean's food web.

Two important planetary ecosystems, coral reefs and polar regions, are on the front lines of the acidification crisis. Coral reefs critical to the protection of coastlines across tropical and subtropical parts of the world will disappear as the rate of erosion exceeds the rate at which corals can rebuild — with staggering repercussions for related ecosystems like mangrove and seagrass.

Meanwhile in the north and south polar regions, marine plankton will be lost; some are already growing thinner and weaker shells. For example, pteropods are an important staple in the diet of salmon, mackerel, herring, cod and baleen whales.

It's clear that this crisis may spin out of control, with devastating effects on vast numbers of species, from small shell-building oysters and reef fish to crabs, whales and sea otters.


Like global warming, the acidification of our oceans is a problem that's vast in scale and demands a rapid and ambitious response. Even though our oceans are absorbing roughly one ton of CO2 per person on Earth each year, almost nothing has been done to curb acidification.

We're going to be part of the solution, and we need your help. Click here to take action. The Center's campaign to fight acidification is using the Clean Water Act to stop the pollution that's causing it — greenhouse gas emissions — as well as to improve water-quality standards and pH monitoring. 

We also work through the Endangered Species Act for the protection of species already directly affected by acidification — for instance, elkhorn coral and staghorn coral and  82 more corals. In 2012, the Center also initiated legal action to compel the government to create a recovery plan for corals that needs to take ocean acidification into account. In 2013, in response to a Center petition, the U.S. Environmental Protection Agency began an in-depth study about combating ocean acidification and reducing the pollution that's causing it. But in the same year, we filed suit against the agency for failing to address ocean acidification killing oysters in Oregon and Washington, challenging the EPA's decision that seawaters in those two states met water-quality standards meant to protect marine life despite disturbing increases in acidity.


Photo by Alexander Vasenin/Wikimedia