Seagrass, a type of underwater plant which flowers and grows quite like terrestrial grasses, is apparently a huge contributor to the world’s ability sequester carbon. Seagrass grows in “meadows,” large patches dominated by one or two species, which are home to many shallow-water and coastal creatures. It forms an integral part of their local ecosystems.
But seagrass also sequesters carbon dioxide at a very high rate, and in one Danish bay, it’s much better at it than anywhere else. Outside of Thurøbund, no meadow seems to hold more than 11,000 grams of carbon per square meter, but the Danish bay sequesters upwards of 27,000 grams per square meter.
Biologists think this might have something to do with the protected nature of the bay. Not protected in a legal sense, but by having less direct contact with the larger ocean. There, when the plants die, they sink to the bottom of the ocean and get buried in sediment, so the carbon they had been storing stays there. In other meadows, these plants are washed out to sea, after which nobody is sure what happens to them.
Seagrass is threatened, as are so many species on the planet. Since 1879, the Earth has lost about 29 percent of its seagrass meadows. Denmark itself has lost between 80 and 90 percent since the 1930s. But because these plants are so good at storing carbon, it’s certainly worth our time to not only find ways to preserve those meadows which still exist, but to find ways to shore them up. If we can get more seagrass to grow, returning to levels before 1879, that could be a huge help in reducing global warming.
While the Earth’s processes of naturally sequestering carbon aren’t likely to save the day, they do put in a lot of work, and finding ways to increase the effectiveness with which they do so could make quite a difference.