Carbon storage by coastal macroalgae is a significant, but neglected, aspect of the global carbon budget.
Our understanding of the global carbon cycle has been reshaped by Saudi Arabia's King Abdullah University of Science and Technology (KAUST) researchers who have helped to reveal a major role for the abundance of seaweed growing around the world’s coasts.
Some years ago, Carlos Duarte, now director of the Red Sea Research Center at KAUST, was among the first scientists to establish that marine vegetation plays a major role in the movement of carbon through the environment and all living organisms. The dominant players in the waters of coastal zones are macroalgae – more commonly known as seaweeds, such as kelp and sargassum.
Now Duarte and Dorte Krause-Jensen from Aarhus University in Denmark have reviewed and quantified the role of macroalgae in trapping carbon. Their estimate is a highly significant 173 trillion grams of carbon sequestered in coastal seaweed, globally, per year .
“Marine macroalgae have largely been excluded from discussion of marine carbon sinks,” says Duarte. He explains that this is due to neglecting the accumulation of macroalgae in deep-sea sediments. His latest review suggests that around 90 percent of global sequestration of carbon by macroalgae could be due to the transport of this vegetation into the deep sea.
The researchers propose two main mechanisms for this transport – seaweed drifting through under-sea canyons and deposition by sinking when the marine vegetation loses its natural buoyancy.
“These processes in many vegetated coastal habitats sequester ten times more carbon dioxide per hectare than a hectare of Amazonian forest,” says Duarte. This highlights the significance of seaweed when compared to a habitat often used as a carbon sink yardstick in discussions about climate change .
“Understanding the major carbon sinks in the biosphere is of paramount importance to identify where there are management opportunities to mitigate climate change,” says Duarte. He explains that understanding where carbon goes provides opportunities for potential interventions that absorb more of the carbon dioxide that human activity releases into the atmosphere.
This latest analysis adds to other recent insights into carbon sequestration gained by Duarte and his colleagues, including new understanding of the role of marine bacteria, and of hydrocarbons deposited into the ocean from the atmosphere (see related articles).
Duarte now plans to use advanced techniques to identify and quantify the significance of macroalgal carbon deposition in existing sediments. One tool will be DNA analysis, which can reveal which species contributed to the carbon in sediments.
The global importance of climate change makes such work vital for planning effective management of the planet.
 Krause-Jensen, D. & Duarte, C. M. Substantial role of macroalgae in marine carbon sequestration. Nature Geoscience advance online publication, 12 September 2016 (doi: 10.1038/NGEO2790).
Michelle D'Antoni | Research SEA
Thawing permafrost produces more methane than expected
20.03.2018 | GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre
Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
20.03.2018 | Physics and Astronomy
20.03.2018 | Physics and Astronomy
20.03.2018 | Earth Sciences