They can strengthen coastlines, break the force of raging waves, shelter fish, crustaceans and migratory birds, purify the water, store as much as 5 percent of the world’s carbon dioxide and pump oxygen into the ocean, in part to make it possible for life on earth as we know it.
These miracle machines are not the latest shiny technical invention. Rather, they are one of nature’s earliest floral creations: seagrass. Anchored to the shores of every continent except Antarctica, these plants (and they are plants, not algae, that germinate, flower, fruit, and set seed) are one of the most powerful yet unheralded climate solutions already on the planet.
Eelgrass restoration is a tool that coastal communities can use to address climate change, both by capturing emissions and mitigating its impacts. Korea, for a conference in the DailyExpertNews, A New Climate.
All over the world, scientists, non-governmental organizations and volunteers are working to restore seagrass meadows, if not to their original glory, then to something far greater and more majestic than the arid, muddy bottoms left behind when damaged or destroyed. .
In Virginia, parts of Britain and Western Australia, among others, seagrass meadows are making a comeback with the helping hands of dedicated researchers and citizen scientists alike. They bring clearer waters, more stable shorelines, and animals and other organisms that used to thrive there. And yet seagrass doesn’t get the attention it deserves, say its supporters.
It’s impossible to know exactly how much seagrass has been lost, because scientists don’t know how much was there to begin with.
Only about 16 percent of global coastal ecosystems are considered intact, and eelgrass is among the hardest hit areas. According to Matthew Long, an associate scientist in marine chemistry and geochemistry at Woods Hole Oceanographic Institution, an estimated one-third of the world’s eelgrass has disappeared in recent decades. “Worldwide, a football field of seagrass is lost every 30 minutes,” said Dr. Long, “and we’re losing about 5 to 10 percent every year at an accelerated rate.”
“Seagrasses are negatively impacted by global stressors: deoxygenation, ocean acidification and global warming,” said Dr. Lung. But local stressors have also played a role in its wilting, primarily in the form of nutrient pollution, largely from agricultural runoff and wastewater, and subsequent algal blooms and diebacks, which first suffocate other plants such as seagrass (a process called eutrophication). . and then, as they decompose, absorb all the oxygen in the water (hypoxia).
While the effects of climate change and increasing human impact have accelerated seagrass loss in recent decades, it’s not a new story.
On Virginia’s east coast, a strong storm in August 1933 that followed debilitating disease and over-harvesting of scallops destroyed what remained of once vast eelgrass meadows. (Eelgrass is a type of eelgrass.) For decades, there was no eelgrass on the ocean side of the coast, said Bo Lusk, a scientist with the Nature Conservancy’s Volgenau Virginia Coast Reserve, though some remained on the part of the coast that the Chesapeake was washed over. Bay.
Dr. Lusk, who grew up in the region, heard stories of lush green carpets of seagrass from his grandmother as a child, who remembered that the shores teemed with life – until they stopped. But then, in 1997, someone reported seeing some bits of seagrass on the ocean shore, probably from seeds that happened to drift south from Maryland and settle in a hospitable neighborhood in Virginia.
After several years of experimentation, Robert J. Orth, a scientist at the Virginia Institute of Marine Science, devised a highly successful method of restoring eelgrass, similar to methods used around the world: In the spring, scientists and hundreds of volunteers collect seeds , which they count and process in the summer and plant in the sediment in the fall.
Since 2003, when restoration efforts began at the Volgau Virginia Coast Reserve, scientists and others have planted about 600 acres of seeds, and eelgrass now covers 10,000 acres, according to Dr. Lusk. Later this year, the Nature Conservancy hopes to sell the first validated seagrass blue carbon credits, based on these restoration efforts, said Jill Bieri, the reserve’s director.
However, the success of the Virginia project has been somewhat difficult to replicate around the world. “You can’t just do this anywhere,” said Dr. Lusk. “If Nature Conservancy hadn’t started this land conservation work 50 years ago, buying up parts of the coast to preserve it, chances are we wouldn’t have the water quality we have now, and this wouldn’t have been the case successful.”
Seagrass recovery will take decades of dedication, said Dr. Lusk. Richard Unsworth, an associate professor of life sciences at Swansea University in Wales and the founder and chief scientific officer of Project Seagrass, a British NGO working on seagrass restoration, said an important part of the work was the long-term promise to the whole ecosystem — the seagrass meadows, but also the people in the community.
“The actions of fishermen, the views of boat owners, the water quality issues – they can all be part of a complex socio-cultural situation, and in the long run it will be a great success, but it is a slow process, not some silver bullet where you plant something and then you made it,” Dr. Unsworth said.
Community involvement has been a necessary component to seagrass’ success, as it takes a lot of work to collect and plant millions of seeds. For Project Seagrass, that included developing a website and app, Seagrass Spotter, that allows users to upload photos of seagrass in the wild (which are then verified by scientists) to help researchers fully map the extent and species of seagrass . around the world, as global seagrass mapping is rather patchy.
But one place that has been well mapped is Shark Bay, a remote part of the coast in Western Australia, where it was discovered that eelgrass from 10 different meadows was actually just one plant, possibly the largest in the world.
There, seagrass has been growing for more than 3,000 years, accumulating carbon in the plant material, as well as in the sediment, said Elizabeth Sinclair, an evolutionary biologist at the University of Western Australia.
But during an extreme marine heat wave from 2010 to 2011, about a third of the eelgrass roof (which is visible above the sand) died and an estimated nine million tons of carbon was released.
Over the past ten years, Dr. Sinclair and her colleagues studied the recovery of the eelgrass – the places where it naturally comes back and where it probably never will, without some help from scientists and the Malgana people, Indigenous Australians who work as rangers.
Despite warming temperatures and the ocean’s changing chemistry making full recovery impossible, it’s still worth doing, said Dr. Australia.
“There are so many logical reasons why we should be doing this,” said Dr. Lusk. “The carbon sequestration is great, coastal protection, all those other things are great, and you can know that in your head, but until you get out in the water and actually spend some time in this system, you don’t have the emotional connection.
“I would continue to do this if carbon was not stored. It just feels good to be there.”