Sea grass restoration helps halt erosion and arrest habitat loss. And sea grass meadows may also be one of best carbon investments around.

That suggests an economic model for seagrass restoration projects and a win-win for the oceans – by sequestering carbon, seagrass may slow ocean acidification.

The world’s seagrass meadows have declined significantly over the past century. Combined with mangrove forests, about one-third of the earlier global mass has been lost. Despite its efficiency in sequestering carbon, seagrass relies on slower clonal (versus sexual) reproduction.

In 2008, the Ocean Foundation began funding sea grass restoration projects around the US, mainly to repair damage caused by boats. Carbon sequestration was a secondary consideration for projects, behind erosion-control and habitat-protection.

The foundation found that seagrass, along with mangroves, take up considerable amounts of carbon. Indeed, scientists think that seagrass meadows take in and stores up to twice as much atmospheric carbon per acre than terrestrial forests.

So the foundation offers “Blue Carbon Offsets.” On the foundation’s SeaGrass Grow! website, donors can calculate their carbon footprint and sponsor seagrass planting as an offset. The offsets have raised about $80,000 so far.

For now, the program is voluntary, but the emergence of viable carbon markets in California and elsewhere creates the possibility of an income-generating, self-sustaining model. The foundation has partnered with Restore America’s Estuaries to certify aquatic vegetation carbon protocols, four for mangrove species and one for seagrass (eel grass).

Mark Spalding, president of the Ocean Foundation, says he expects to generate between $250,000 and $750,000 annually in the early years, as the market for such certificates develops. Certification in California is a year or two away, but once accepted, the protocols should meet the European criteria as well, he says.

“We really want to take this endeavor toward a paid offsets model,” Spalding says. “Right now carbon offsets are really associated with terrestrial forests, but the ocean is the number one carbon sink on the planet.”

Photo courtesy of Beau Williams of Seagrass Recovery.

Editor’s Note: This article is part of a series on Oceans and Sustainable Fisheries,  in association with SOCAP 13, the Social Capital Markets conference in San Francisco, Sept. 3-6. Impact IQ readers can get a 30% discount for SOCAP 13 by registering here.