Coastal seagrass project aims to enter the global carbon market

A decades-long research project in Virginia’s coastal bays may soon be among the first to enlist the ocean’s help in the fight against climate change.  Today, businesses that produce greenhouse gases can compensate for their emissions by purchasing carbon offsets that fund reforestation projects or support renewable energy efforts like wind farms and solar energy, but leaders of a seagrass restoration partnership between the University of Virginia’s Virginia Coast Long-Term Ecological Research Project (VCR/LTER), The Nature Conservancy (TNC) and the Virginia Institute of Marine Science (VIMS) are working to make the project one of the world’s first registered seagrass carbon offset options.

Extracting carbon dioxide, or CO2, from the atmosphere is one of the most important things plants do to mitigate the effects of climate change. The carbon storing capacity of the earth’s nearly three trillion trees plays an important part in that process, but environmental scientists estimate that coastal wetlands, which include tidal marshes, mangrove forests and seagrass meadows can store more carbon in their soils per acre than terrestrial forests.

“The ocean removes a lot of carbon from the atmosphere,” said Matthew Oreska, a former graduate of UVA’s Department of Environmental Sciences Ph.D. program who worked on the LTER’s seagrass project, “And seagrass systems are an important part of the ocean’s carbon cycle.”

Growing recognition of the role that seagrass plays in the health of the environment and the opportunity it presents to offset the harm caused by energy sources like oil, coal and natural gas that introduce carbon into the atmosphere, has led to increased efforts by environmental scientists to improve the ability of coastal wetlands and seagrass meadows to capture and store that CO2, which is often called “blue carbon.”

For over 20 years, UVA has worked in partnership with The Nature Conservancy and VIMS on a project to restore eelgrass to Virginia’s seaside bays. The seagrass that once thrived along Virginia’s coast, once a vital part of a habitat that supported the region’s lucrative commercial fishing and bay scallop industry, had been wiped out by disease and devastating storms in the 1930s. After the discovery of remnant patches of eelgrass, a restoration project was launched in 1999 to reseed and restore the eelgrass habitat.

The work was begun by VIMS, and now in partnership with The Nature Conservancy, they share the work of planting seagrass seeds and monitoring the habitat while UVA provides the scientific expertise necessary to collect the data needed to quantify and verify the impact those efforts have on the climate through the VCR-LTER program based in Oyster, Virginia.

Over the past two decades, scientists and volunteers affiliated with the project have broadcast more than 70 million eelgrass seeds within four previously barren seaside lagoons, spurring a natural expansion that has so far grown to nearly 9,500 acres, making it the single largest eelgrass habitat between North Carolina and New York’s Long Island Sound and making it one of the most successful marine restoration projects in history.

The idea to expand the scope of the project to make it part of the global effort to fight climate change was a by-product of that success and of work by UVA’s Department of Environmental Sciences to link coastal restoration with carbon market finance through the creation of a seagrass carbon offset credit methodology, said Oreska who authored the international protocol for issuing carbon offset credits for seagrass restoration. According to his co-author Karen McGlathery, director of UVA’s Environmental Institute and lead investigator with the VCR-LTER, the new seagrass restoration project will use this blue carbon methodology to verify its environmental impact, an approach that is likely to become the gold standard for other projects of this kind.

“The loss of tropical rainforests in places like the Amazon releases as much CO2 into the atmosphere as the industrial emission of some countries,” said Oreska. “Greenhouse gas accounting methodologies already existed to facilitate restoration projects trying to offset tropical forest emissions. We wanted to extend the same concept to marshes and seagrass meadows, but a new methodology was needed to deal with the differences in aquatic systems.”

The project’s success caught the attention of the nonprofit conservation group Restore America’s Estuaries. That group enlisted the help of an organization called Verra, which sets verifiable standards for climate action and sustainable development programs, to develop the methodology that will ultimately lead to the project’s status as a verifiable, or registered, carbon offset. Registration of the program on the voluntary carbon market will provide the transparency necessary for a third-party to authenticate the impact of the project on the environment and assess its climate mitigation value for buyers of carbon offsets. Revenues generated by carbon offset purchases will provide the project with additional funding needed to support the ongoing costs of monitoring and managing the eelgrass meadows, which is critical to the project’s continued success.

“There are many offset projects using nature that claim to take CO2 out of the atmosphere, but without verification, it’s not clear whether or not they are,” said McGlathery. “With this project, we’ll have that accountability, and that raises the profile of using these natural systems and the role that Virginia is playing.”

In addition to the project’s global implications, its ongoing work will continue to provide a variety of benefits to Virginia residents on the Eastern Shore. Long-term studies show that, in addition to carbon sequestration, the project has led to significant increases in the abundance of fish and other aquatic life in the region, it has improved water quality and it has helped reduce coastal erosion that, by some estimates, has claimed as much as 500 acres of arable coastal land, leading to approximately $23 million in property value losses each year.

“The two main industries on the Eastern Shore are farming and aquaculture, and a lot of the farmers raise clams and oysters too, so they understand that the health of the Chesapeake Bay’s lagoons is important,” said Buck Doughty, the VCR-LTER facility coordinator.

Doughty traces his family history back 12 generations on the Eastern Shore. He recalls his father’s stories about how the region had changed due to the loss of the seagrass population in the mid-20^th century and how it impacted the region that had once been the one of the nation’s largest seafood suppliers.

“I remember him telling me that when the seagrass meadows died, everything died with them,” Doughty said. “But I love seeing how the health of the lagoons is coming back. It’s amazing to see how well they’re doing. They’re healthy again.”

Despite its success in the region, the project’s status as a registered blue carbon project could also take that success to a new level.

“Our long-term carbon research was the basis for the Virginia Senate Bill passed in April 2020 to allow carbon offset credits for seagrass restoration, but it’s not just about Virginia’s Eastern Shore,” McGlathery said. “We want to be a model for other projects like this one. We wrote the protocol, and we have proof of concept that what we’re doing is benefiting the state, and we’re also setting the standard and inspiring other projects of this kind. It’s a real opportunity for us to take a leadership role on a global level.”