The conversation around carbon emissions often finds us looking up. But what of our oceans?

Greenhouse gases take just as immense a toll on our planet’s waters as on the atmosphere—and Dr. Jessica Cross, a research oceanographer with the National Ocean and Atmospheric Administration (NOAA) in Seattle, WA, has long been studying the effects. The term you need to know? Ocean acidification.

What Is Ocean Acidification?

The ocean absorbs about 30% of the carbon emitted into the atmosphere. Once in the water, said carbon dissolves, undergoes a series of chemical reactions, and lowers the pH of the ocean—a process known as ocean acidification.

According to Cross, that cascade of chemical reactions affects the ocean twofold, creating more hydrogen molecules (the “acidification” part) and a reduction of carbonate ions. The result is a climate-driven threat to marine life and ocean ecosystems as a whole.

What Are the Effects of Ocean Acidification?

“A lot of organisms in the ocean use carbonate ions to regulate their biological functions, whether that’s things like building shells and skeletons out of carbonate ions or really just using those in a sensory capacity to sort of feel out their environment around them,” says Cross.

For fish, whales, and the like, the upped acidity messed with the ability to self-regulate, while shellfish and corals experience a decrease in both metabolic ability and the calcifying materials necessary to build and maintain their hard exteriors. (If the pH gets too low, the shells will actually being to erode.)

In terms of industry, ocean acidification coupled with extreme weather creates a major issue for fisheries. If ocean acidification is left unchecked, it’s estimated that the U.S. Shellfish industry will lose more than $400 million annually by the year 2100.

“All of these stressors together probably have led to a big crash in the crab fishery in Alaska across the last several years,” says Cross, who notes that pinpointing the exact cause is a difficult task.

What Can You Do to Help?

“One of the ways that we’re thinking about mitigating ocean acidification risk now, is through really trying to support carbon removals,” says Cross. “In some cases, that can be about restoring an ecosystem that may have been damaged.”

These ecosystems can take the form of wetlands, seagrass beds, and natural kelp beds, all of which naturally pull carbon dioxide out of the system for their own use.

The real answer, though, is the curbing of carbon emissions.

“The more carbon dioxide we put in the atmosphere, the more carbon dioxide the ocean soaks up,” says Cross. The solution, then, is simple: “One of the best things that we can do to slow ocean acidification is to stop putting carbon dioxide in the atmosphere.”