Seagrasses and Carbon: study shows they store carbon as well as forests

A press release issued today by the National Science Foundation highlights a recent study that shows that seagrasses are able to store as much carbon as forests.  Florida International University and the National Science Foundation's Florida Coastal Everglades Long-Term Ecological Research site worked together with scientists from Spain, Australia, United Kingdom, Denmark, and Greece to determine that, although seagrass meadows occupy less than 0.2 percent of the world's oceans, they are responsible for more than 10 percent of all the carbon buried annually in the sea.

"Seagrasses are a vital part of the solution to climate change and, per unit area, seagrass meadows can store up to twice as much carbon as the world's temperate and tropical forests.  The [study] results demonstrate that coastal seagrass beds store up to 83,000 metric tons of carbon per square kilometer, mostly in the soils beneath them. As a comparison, a typical terrestrial forest stores about 30,000 metric tons per square kilometer, most of which is in the form of wood," the press release stated. 

"Seagrasses have the unique ability to continue to store carbon in their roots and soil in coastal seas," said James Fourqurean, Florida International University scientists and lead author of the study. "We found places where seagrass beds have been storing carbon for thousands of years."       

And like forests that are subject to deforestation for land development and lumber, seagrasses are among the world's most threatened ecosystems.  Some 29 percent of all historic seagrass meadows have been destroyed, mainly due to dredging and degradation of water quality.  At least 1.5 percent of the Earth's seagrass meadows are lost every year.   

Seagrasses can, when properly managed, regenerate themselves, perhaps even better than denuded forests. According to Karen McGlathery, one of the study's co-authors and a scientist at the University of Virginia, "One remarkable thing about seagrass meadows is that, if restored, they can effectively and rapidly sequester carbon and reestablish lost carbon sinks."       

Besides the ability to sequester carbon, seagrasses play an important role in filtering sediment from the ocean, protecting the shoreline from flood and storm damage, and providing shelter for a variety of marine life and their offspring.  The study's conclusions emphasize the need for conserving and restoring seagrass meadows as they reduce greenhouse gas emissions and increase carbon stores while delivering important ecological benefits to coastal communities as well.  

Source: NSF.gov
                 

Whales & Carbon Sequestering: new study shows potential carbon storing by large whales

Following up on my recent post about whalers being early and unintentional environmentalists, here's some interesting news coming out of the University of Maine. A study conducted by researchers from the university, in addition to the University of British Columbia and the Gulf of Maine Research Institute, outlines the enormous carbon sequestering ability of whales and other large marine species; an ability that puts these animals on a par with other carbon storing organisms like peat bogs, grasslands and trees.

As an example, a blue whale can store up to 9 tons of carbon, surpassed only by large trees. But since the populations of blue whales have been reduced by as much as 99 percent, the planet has lost a vital source of carbon sequestration. Andrew Pershing, one of the Maine research scientists, describe the loss of potential carbon storage due to a century of whaling as the equivalent of burning more than 70 million acres of temperate forest or 28,000 SUVs driving for 100 years.

Many scientists have proposed "iron fertilization" as a method for sequestering carbon in the oceans. This process bonds iron particles with carbon and then, as the iron sinks into deep ocean depths, it takes along with it an amount of carbon. Pershing, whose research was supported by NASA and the National Science Foundation, sees whale conservation as equally if not more effective.

Pershing noted, “The big surprise was in our calculations comparing carbon exported by sinking whale carcasses to the carbon exported by iron fertilization. If we had all the whales we used to have, they would remove the same amount of carbon in a year as 200 of the most efficient iron fertilization events. What that tells me is that we can get significant carbon savings by conserving resources in the ocean, protecting whales, larger fish and sharks.”

Additionally, The larger whale and marine species prove to be more efficient at carbon storage than smaller species. While all animals absorb some measure of carbon (we're carbon lifeforms, remember?), the larger animals require less food (which equates to carbon) per unit of weight. The same amount of food can support more whale tonnage than, say, compared to penguins.

As the University of Maine reported in a recent press release, according to Pershing, “In many ways bigger is better.” Any whale could have told us that.

Read the University of Maine press release.