The green meadow of Posidonia underwater that exist close to coastlines, and are seriously damaged by polluting discharges, trawling and pleasure craft facilities, are capable of capturing and storing carbon twice the lush tropical forests. A study of seagrass, thousand around the world has shown that under the sea there are 'sinks' that help fight climate change.
The work has been developed by a team of scientists from several countries, including experts from the Spanish National Research Council (CSIC) and has been published in the journal Nature Geoscience. "
"It is very important because these grasslands have now acquired, as well as ecological value, another economic value in the form of carbon credits. Spain now has to buy these credits because their emissions are higher than they should. Keeping these meadows could prevent that expense, "said Miguel Angel Mateo, one of the authors, the Center for Advanced Studies (CSIC) to ELMUNDO.es.
Research is the first of its kind to be based on direct data collection. In total, the scientists collected a total of 3,640 samples of 946 subsurface seagrass around the planet and all species. "These plants, through photosynthesis, carbon trap water and fix and buried for centuries. We, boats, we have taken samples to a meter deep and we have analyzed the carbon that is accumulated," says the researcher.
Pollution of one year
The work reveals that all grasslands accumulate between 4,200 and 8,400 million tons of carbon just one meter below these parderas, with a peak of 20,000 million tones. These 8,400 million CO2 we emit is what all human beings over one year, according to the scientist.
These figures mean that the plants that surround the coastline can reach up to 830 tons bury carbon per hectare, while tropical forests, the so-called 'lungs' of the planet, have a storage capacity of 300 tons per hectare. Matthew notes that even these aquatic plants could 'sequester' more carbon, as one meter have only deepened.
Thus, scientists warn of the delicate situation being experienced by these meadows around the globe. Some studies estimate that more than a quarter of its length has already been destroyed (other increase that percentage to 50%) due to trawling and uncontrolled construction costs.
The CSIC oceanagrado Carlos Duarte said in a statement insists on its importance in the fight against climate change: "The great capacity of grasslands as sinks is that this ecosystem more fixed carbon than eat or breathe. Unlike of forest soils, sediment in the seagrass accumulates vertically as sea level rises and therefore can increase their volume over centuries and millennia. The absence of fire at sea also contributes to these carbon sinks persist "he says.
The researchers point out that although the grasslands occupy less than 0.2% of the ocean surface, are the 'enterradoras' of more than 10% of all annual carbon absorbed by the oceans and making it indefinitely.
Interestingly, one of the species that are able to accumulate more carbon is the Mediterranean Posidonia, which have detected carbon deposit thickness of up to four meters. However, it is one that covers a greater danger because of the high level of destruction on the coast.
"Every year we lose 5% of Posidonia and the problem is not just that we lose deposits of carbon sequestration, but the space occupied by the plant is converted into carbon emitter, because it starts out all carbon had accumulated and passed to the atmosphere, "says Matthew.
The researcher points out that currently buy a ton sinks for carbon costs six euro’s, although it has come to be 30 euro’s. "For a country, preserve its seagrass is to have an important economic asset," he argues.
On the other hand, is not known with precision the amount of grasslands on the planet. It is estimated that all marine plants ranging between 330,000 and 600,000 sq km, but estimates are unacceptably.