Wednesday, September 26, 2012

Salt Marsh Carbon Slows Climate Warming

Salt Marsh Carbon May Play Role in Slowing Climate Warming

ScienceDaily (Sep. 26, 2012) — A warming climate and rising seas will enable salt marshes to more rapidly capture and remove carbon dioxide from the atmosphere, possibly playing a role in slowing the rate of climate change, according to a new study led by a University of Virginia environmental scientist and published in the Sept. 27 issue of the journal Nature.

Carbon dioxide is the predominant so-called "greenhouse gas" that acts as sort of an atmospheric blanket, trapping Earth's heat. Over time, an abundance of carbon dioxide can change the global climate, according to generally accepted scientific theory. A warmer climate melts polar ice, causing sea levels to rise.

Aerial view of a salt marsh at Virginia's Eastern Shore. (Credit: Fariss Samarrai)
A large portion of the carbon dioxide in the atmosphere is produced by human activities, primarily the burning of fossil fuels to energize a rapidly growing world human population. "We predict that marshes will absorb some of that carbon dioxide, and if other coastal ecosystems -- such as seagrasses and mangroves -- respond similarly, there might be a little less warming," said the study's lead author, Matt Kirwan, a research assistant professor of environmental sciences in the College of Arts & Sciences.

Salt marshes, made up primarily of grasses, are important coastal ecosystems, helping to protect shorelines from storms and providing habitat for a diverse range of wildlife, from birds to mammals, shell- and fin-fishes and mollusks. They also build up coastal elevations by trapping sediment during floods, and produce new soil from roots and decaying organic matter.

"One of the cool things about salt marshes is that they are perhaps the best example of an ecosystem that actually depends on carbon accumulation to survive climate change: The accumulation of roots in the soil builds their elevation, keeping the plants above the water," Kirwan said.

Salt marshes store enormous quantities of carbon, essential to plant productivity, by, in essence, breathing in the atmospheric carbon and then using it to grow, flourish and increase the height of the soil. Even as the grasses die, the carbon remains trapped in the sediment. The researchers' model predicts that under faster sea-level rise rates, salt marshes could bury up to four times as much carbon as they do now.

"Our work indicates that the value of these ecosystems in capturing atmospheric carbon might become much more important in the future, as the climate warms," Kirwan said. But the study also shows that marshes can survive only moderate rates of sea level rise. If seas rise too quickly, the marshes could not increase their elevations at a rate rapid enough to stay above the rising water. And if marshes were to be overcome by fast-rising seas, they no longer could provide the carbon storage capacity that otherwise would help slow climate warming and the resulting rising water.

"At fast levels of sea level rise, no realistic amount of carbon accumulation will help them survive," Kirwan noted.

Kirwan and his co-author, Simon Mudd, a geosciences researcher at the University of Edinburgh in Scotland, used computer models to predict salt marsh growth rates under different climate change and sea-level scenarios.

The United States Geological Survey's Global Change Research Program supported the research.

Online at (re-posted from):

Journal Reference:

Matthew L. Kirwan, Simon M. Mudd. Response of salt-marsh carbon accumulation to climate change. Nature, 2012; 489 (7417): 550 DOI: 10.1038/nature11440

Thursday, September 20, 2012

Blue Carbon Portal

Blue Carbon Portal Provides Home for International Blue Carbon Community

20 September 2012 / GRID-Arendal / Arendal, Norway

GRID-Arendal and Blue Climate Solutions today unveiled the redesigned ‘Blue Carbon Portal’, the world’s premier comprehensive community-based website for all matters related to blue carbon. Blue carbon is a concept that advances the sustainable management of coastal marine ecosystems that store and sequester atmospheric carbon, thereby helping to mitigate climate change.

Blue carbon ecosystems include mangrove forests, seagrass meadows, and saltwater marshes also important for the vital ecosystem services they provide, such as coastal fisheries, shoreline protection, related eco-tourism and the conservation of marine biodiversity.

Seargass meadows can store carbon and thereby help mitigate climate change, while serving as important habitat for many marine species such as this endangered sea turtle (Credit: Steven J Lutz).

The Blue Carbon Portal continues its support the rapidly growing blue carbon community and international efforts such as the United Nations Environment Programme’s (UNEP) Blue Carbon Initiative. It provides a virtual space to increase transparency and accessibility of information, helping initiatives to connect, share ideas and resources.

Features of the Blue Carbon Portal include:
  • The Blue Carbon Blog and social media connectivity (e.g., Twitter Feed);
  •  A geospatial map utility depicting global blue carbon projects and initiatives;
  •  A resources page for all blue carbon publications, presentations and videos; 
  • A calendar of blue carbon events; and 
  • A directory of blue carbon initiatives.
“As started in 2010, the redesigned portal is intended as a platform for community development and you will see things change and evolve: new contributors, additional links, resources and much more,” said Steven Lutz, Blue Carbon Project Manager at GRID-Arendal and Senior Adviser to Blue Climate Solutions. "We welcome everyone interested or engaged in blue carbon to participate in the development of this site. If you have a blue carbon story or activity that you would like to see incorporated or if you would like to advertise a meeting, or share a new resource then we would love to hear from you.” 

To get involved, contact the Blue Carbon Portal’s administrator via links on the sites web site:


GRID-Arendal is an official United Nations Environment Programme's (UNEP) Centre located in Southern Norway. Established in 1989 as a Norwegian foundation, its mission is to provide environmental information, communications and capacity building services for information management and assessment. Grid-Arendal website:

Blue Climate Solutions is a project of The Ocean Foundation and is involved in advancing the blue carbon concept through education and advocacy with national governments, international bodies and the marine conservation community. Blue Climate Solutions website:

Monday, September 17, 2012

Sea Otter Carbon?

According to a recent North American study, sea otters can help mitigate Climate Change, through their role as the natural stewards of kelp forests.

The Sea Otters help keep the number of kelp munching sea urchins down, allowing the forests are to absorb up to 12 times more carbon dioxide than when the plants aren't protected from the urchins. The study was led by researchers from the University of Southern California, Santa Cruz.

In a ScienceDaily article the aurhor's estimate that the CO2 removed from the atmosphere via the otter-kelp link could be worth between $205 million and $408 million on the European Carbon Exchange. "An alluring idea," they write, would be to sell the carbon indirectly sequestered by the sea otter protected kelp forest "as a way to pay for their reintroduction and management or to compensate losses to shell fisheries from sea otter predation."

According to Discovery News, Chris Wilmers, a co-author of the study, issued a statement that included a call to for the contributions of animals to be included in methods of sequestering carbon. The study's abstract states "predator-induced trophic cascades likely influence the rates of C flux and storage in many other species and ecosystems."

This concept may lead to further exciting opportunities to expand blue carbon...

Thanks Guys! Study Shows Sea Otters Fight Global Warming by Protecting Kelp from Sea Urchins

Treehugger / Michael Graham Richard / September 11, 2012

© Jaymi Heimbuch
Cute Climate Warriors!

According to a new study by researchers from the University of California, Santa Cruz, sea otters play an important role in helping the coastal seaweed forests absorb as much carbon dioxide as possible. The little furry creatures are natural predators to sea urchins, which in turn like to munch on kelp, a very common family of large seaweeds. According to the study, which looked at 40 years of data on sea otters and kelp blooms from Vancouver Island to the western edge of Alaska's Aleutian Islands, when sea otters are around, underwater kelp forests can absorb 12 times more carbon dioxide than when the plants aren't protected from urchins (those spikey little devils!).
More otters mean more kelp and since the plant is particularly good at capturing carbon through photosynthesis, this also could mean less CO2 in the atmosphere. [...]

The authors acknowledge that otters probably aren't the answer to rising CO2 levels, a major contributing factor to global warming, but the researchers say their study illustrates the impact animals can have on the atmosphere.

"Right now, all the climate change models and proposed methods of sequestering carbon ignore animals. But animals the world over, working in different ways to influence the carbon cycle, might actually have a large impact," UC Santa Cruz professor Chris Wilmers, a co-author of the study, said in a statement. "If ecologists can get a better handle on what these impacts are, there might be opportunities for win-win conservation scenarios, whereby animal species are protected or enhanced, and carbon gets sequestered." (Discovery News)
That's a very good point. For our climate models to be more accurate, the impact of various animal populations should be accounted for (as much as possible), and this could even give more weight to the argument for conservation and the reintroduction of animals in certain ecosystems.

Sea otters in themselves might not have the biggest impact on the carbon cycle, but I'm sure there are many other species that do similar things, and when you add all of them together, you probably get a pretty big impact.

Besides, who doesn't love sea otters?


More links:

Sea Otters May Be Global Warming Warriors. Discovery News, Sep. 10, 2012 (including a link to research on sea otter poo)

How Sea Otters Can Reduce CO2 in the Atmosphere: Appetite for Sea Urchins Allows Kelp to Thrive. ScienceDaily. Sep. 7, 2012


Chris Wilmers, James Estes, Matthew Edwards, Kristin L. Laidre and Brenda Konar. Do trophic cascades affect the storage of flux of atmospheric carbon? An analysis of sea otters and kelp forests. Frontiers in Ecology and the Environment, 2012 (in press)

Friday, September 14, 2012

Blue Carbon Emissions from Coastal Ecosystems

Degradation and destruction of the world's seagrasses, tidal marshes, and mangroves may generate up to a billion tons in carbon dioxide emissions annually, reports a new study published in the journal PLOS ONE - 'Estimating Global “Blue Carbon” Emissions from Conversion and Degradation of Vegetated Coastal Ecosystems' by Pendleton et al. (Open access).

Migrating Brown Pelicans over marshland (Allan McDavid Stoddard, Shutterstock

‘Blue Carbon’ Adding to Carbon Emission Blues

Climate Central | Wednesday, September 12th, 2012 | by Michael D. Lemonick

According to a new paper in the journal PLOS ONE, so-called blue carbon – carbon that is pulled from the atmosphere by coastal vegetation including mangroves, sea grasses and salt marshes and stored away in sediments at the edge of the sea -- is now being released at the prodigious rate of between 150 million and 1.02 billion tons every year.

That’s between 3 and 19 percent of the carbon released by deforestation, say the authors, and results in economic damage of between $6 billion and $42 billion annually.

The reason carbon is escaping after being stored for many tens of thousands of years, co-author Daniel Donato of the University of Wisconsin, Madison, said in an interview, is “disturbances” from human activity.

“There’s a whole range of them,” Donato said, including the conversion of coastal mangrove swamps to shrimp aquaculture, conversion of marshes to rice paddies, creation of river dams that starve downstream areas of sediments, offshore dredging, and urban development, to name just a few.

Global distribution of seagrasses, tidal marshes and mangroves (taken from Pendleton et al. 2012)
Natural forces, such as hurricanes, disturb coastal ecosystems, too. “Those have been happening for millennia, and the ecosystems have evolved to handle them,” Donato said. It's far more difficult to recover from coastal development and construction, which tend damage ecosystems far more severely, and far more permanently. 

Until recently, few thought much about blue carbon. “It really started getting attention only in the past year,” said co-author Linwood Pendleton, a resource economist at Duke University’s Duke’s Nicholas Institute for Environmental Policy Solutions and the acting chief economist at NOAA as well. “At first, people didn’t know whether to take it seriously or not.”

Late last year, Pendleton organized a meeting to talk about the issue and assess the state of the science; the new paper, written jointly by participants in that meeting, is the result.

Once the scientists began looking into it, Donato said, “we realized that organic matter can accumulate into these huge, deep layers that can be as much as 25 feet thick. The plants grow and die, but once they’re buried under sediments, the lack of oxygen means they don’t decompose.”

The amount of buried carbon per acre is significantly more than the amount stored in a tropical rainforest, he said, which most people think of as a major carbon storehouse. And that's true even if you only assume the buried layer of blue carbon is only 3 feet deep, which Pendleton and his colleagues did for their calculations so they'd be sure to err on the side of being conservative.

Even so, the emissions and cost figures the authors came up with span a wide range. The reason, Pendleton said, is that while ecologists have a good idea of how fast salt marshes and sea grass habitats are being disturbed, they’re more uncertain about what’s happening to mangroves.

Nevertheless, the study is a crucial first step in understanding an important source of atmospheric carbon, and in figuring out how to limit emissions.

“We’re going to submit this to the IPCC for their next major report,” Pendleton said, “and say ‘this seems to be a substantial source of carbon. Policymakers should figure out what to do about it.”

Story available at:

Reference: Pendleton, Linwood et al. (2012) Estimating Global “Blue Carbon” Emissions from Conversion and Degradation of Vegetated Coastal Ecosystems. PLoS ONE 7(9). doi:10.1371/journal.pone.0043542. Available at: 

Tuesday, September 4, 2012

Oil Spill Impacts Blue Carbon Ecosystem

Oil Threatens Curaçao Marine and Coastal Wildlife

Deep Sea News published a guest post relating the experience of an oil spill in a mangrove area on the Caribbean Island of Curaçao. In her post, Dr. Kristen Marhaver shares her thoughts on the impacts of oil on mangrove ecosystems. According to Kristen, following bad wind conditions caused by the tropical storm Isaac, oil from a storage tank at Curaçao's Isla Refinery was pushed into a mangrove forest, severely contaminating habitat and wildlife. Kristen is a Postdoctoral Scholar at the University of California at Merced, studying coral reefs on Curaçao.

Oil spill in Curacao saliña. Photos by Kristen Marhaver.

Guest Post: Crude oil insults in the Caribbean

Excerpted from - Deep Sea News | Wednesday, August 29th, 2012 | by Kristen Marhaver

"An oil spill in the news is an abstract thing. Though I had seen photos from the Exxon Valdez spill and video from the Deepwater Horizon blowout, I hadn’t prepared to be so deeply insulted by an oil spill in person. Crude oil is the blackest black there is. In a shallow bay in the hot Caribbean sun, it had formed greasy pavements and tar balls almost impossibly goey. It shellacked anything it touched – animal, mineral, or vegetable. I watched a painted-black crab stumble across the ground. Tar balls bobbed between paved-black rocks and the dense underwater branches of mangrove trees, where juvenile fish usually hide from predators. The mangroves’ thin root-like breathing structures poked up above the water surface, slimed with crude and certainly clogged. The arboreal version of black lung. A flock of five flamingos took flight, with black patches on wings where they didn’t belong."

- Posted by Sven Stadtmann, GRID-Arendal