Ocean acidification: A wake-up call in our waters
In a high carbon dioxide world, dangerous waters ahead Science tells a disturbing story
For good reason, ocean acidification is often called “climate change’s evil twin.” The overload of carbon dioxide (CO2) in our oceans is literally causing a sea change, threatening fragile, finite marine life and, in turn, food security, livelihoods and local to global economies.
Like a sponge, our oceans are absorbing increasing amounts of CO2 from the atmosphere. Over the past 200 years, the world’s seas have absorbed more than 150 billion metric tons of carbon from human activities. Currently, that’s a worldwide average of 15 pounds per person a week, enough to fill a coal train long enough to encircle the equator 13 times every year. CO₂ concentrations are now higher than at any time during the past 800,000 years, and the current rate of increase is likely unprecedented in history.
Emerging ocean acidification hotspots around the globe
For good reason, #ocean acidification is called “osteoporosis of the sea.” Ocean acidification can create conditions that eat away at the minerals that oysters, clams, lobsters, shrimp, coral reefs, some seaweed plants and other marine life use to build their shells and skeletons.
Human health, too, is a concern. In the laboratory, many harmful algal species produce more toxins and bloom faster in acidified waters. A similar response in the wild could harm people eating contaminated shellfish and sicken fish and marine mammals. And while ocean acidification won’t make seawater dangerous for swimming, it will upset the balance among the multitudes of microscopic life found in every drop of seawater. Such changes can affect #seafood supplies and the ocean’s ability to store pollutants, including future carbon emissions.
In 2015, the first nationwide study showing the vulnerability of the $1 billion U.S. shellfish industry to ocean acidification revealed a number of hotspots: the #Pacific Northwest, Long Island Sound, Narragansett Bay, Chesapeake Bay, the Gulf of Mexico, and areas off Maine and Massachusetts. Also at risk are Alaska’s fisheries, which account for nearly 60 percent of U.S. commercial fish catch and support more than 100,000 jobs.
Ocean acidification is weakening coral structures in the Caribbean and in cold-water reefs in waters off of Scotland and Norway. It is a concern in the Great Barrier Reef, where living corals have declined by half over the past three decades, reducing habitat for fish and the resilience of the entire reef system. Native fisheries in Patagonian waters may also be threatened. Dramatic change is apparent in the #Antarctic, where the frigid waters can hold so much CO2 that shelled creatures dissolve in the corrosive conditions, affecting food sources for fish, birds and marine mammals.