HR4RS stamp
Libya Munoz Aguilera
The sebadal is the denomination given in the Canary Islands to the underwater meadows formed by the plant species Cymodocea knotosa, a key element to mitigate climate change. In the last 20 years, approximately 50% of these sebadas have been lost, although, despite this dramatic decline, 11% of the total carbon stored by this species in Spain is found in the Canary Islands.
These meadows have great ecological and economic relevance for the islands due to the various services they offer, such as CO2 sequestration, water purification and support for marine biodiversity. In addition, they are the habitat of commercial fish species of great gastronomic interest in the Canary Islands such as "la vieja", whose survival and breeding depend on these marine plants.
The study titled Mapping and assessment of changes in seagrass beds and their associated blue carbon under past, present and future scenarios and signed by the researchers from the Rey Juan Carlos University Miriam Montero Hidalgo and Fernando Santos Martín, together with Fernando Tuya, Ricardo Haroun and Francisco Otero from the BIOCON-ECOAQUA group of the University of Las Palmas de Gran Canaria (ULPGC), has been published in the scientific journal with a high impact index Science of the Total Environment. The study demonstrates the decline of the Canarian sebadales and their carbon storage capacity and climate regulation, in addition to estimating the economic impacts that their disappearance could cause.
If current trends continue, the losses could reach 126 million euros in future damage (0,32% of the current GDP of the Canary Islands) in 2050 due to a possible emission of 1,43 megatonnes of CO2, which are currently contained in these prairies and that "would be equivalent to what 572.000 cars emit in a year, 32% of the Canarian car fleet," explains Miriam Montero. On the contrary, if the extension of the sebadales remains stable, 0,75 megatonnes could be sequestered in the coming years until 2050, which would mean a saving of 73 million euros in future damage.
blue carbon maps
“This study identifies the areas and environmental pressures on which it is necessary to act, and studies future management scenarios, giving a scientific and economic reason for the conservation of seagrasses”, says Miriam Montero.
The creation of a “mapping” of blue carbon stored by the Cymodocea knotosa is novel, since blue carbon maps are currently scarce and are normally focused on other "seagrass" species, such as those of the genus Posidonia, or in those shallow intertidal seagrasses, which are those that are less than 10 meters from the surface.
However, the Cymodocea knotosa in the Canary Islands it is an opportunistic meadow type and with deeper waters, which is why it has been studied less. This work opens the doors to an area barely explored, evaluating the storage of CO2 in the Cymodocea knotosa using real local data from the entire Canary Islands, as well as high spatial resolution distribution maps of these seagrass beds.
“Our methodology generates scientific evidence to value the ecosystem created by the Cymodocea knotosa and to be able to take it into account in decision-making and in its management”, concludes Miriam Montero.
This study is part of the efforts that are being carried out from Spain as part of the European project MOVE-ON Project for the mapping and assessment of ecosystem services in the outermost regions and overseas territories of the EU.
