Burning fossil fuels doesn’t just pollute the atmosphere. The ocean absorbs about a quarter of the CO₂ emitted by human activity each year.

“The ocean absorbs carbon dioxide like a sponge,” says Aurora Ricart of the University of California, Davis. 

She explains that increased concentrations of CO₂ cause water to become more acidic, which can harm marine animals.

But her research indicates that in some areas, coastal seagrasses can help reduce that acidity. 

As the underwater plants grow and photosynthesize, they absorb CO₂, which Ricart says can reverse ocean acidification at local scales.

Over six years, she and her team monitored seagrass meadows along more than 600 miles of California coastline. They found that, on average, the water in these areas was less acidic than in areas without vegetation. 

The effect persisted even at night, when plants are not actively performing photosynthesis. 

She says the findings suggest that seagrass meadows may be able to help alleviate ocean acidity and protect vulnerable species. 

So she says it’s important to conserve these ecosystems and restore them when they have been damaged. 

Reporting credit: Sarah Kennedy/ChavoBart Digital Media and Diana Madson