Ria Formosa, a Blue Carbon Warehouse
In terms of global changes, marshland and seagrass ecosystems contribute by sequestering about 40 times more CO2 than that of tropical, boreal or temperate forests. Operating through the RiaValue project coordinated by Rui Santos, the ALGAE-Ecology of Marine Plants Group at the Centre for Marine Sciences (CCMAR). assessed the services provided by the Ria Formosa in order to gauge its social and economic importance and contribute to improving the conservation and management measures and policies applied to the Nature Park.
The Ria Formosa is one of the most important coastal lagoons in southern Europe. A mesotidal lagoon, it stretches along 55 km of Portugal’s southern coast. The seagrass and salt marshes within the park are among the most valuable ecosystems on the planet in terms of the flow of services and the values they support. These ecosystems are recognised as habitats targeted for conservation (EU Habitats Directive), as well as being biological elements that indicate the ecological status of coastal waters (EU Marine Strategy Framework Directive). These environments, however, are highly vulnerable to human impact, such as quantities of nutrients and physical disturbances, for example, both on a local and global scale, which have resulted in widespread losses of these habitats. In recent decades, a third of the marsh and seagrass ecosystems around the world have been destroyed due to anthropogenic impacts.
The Ria Formosa is a blue carbon warehouse. “Specifically regarding blue carbon, which is sequestered by coastal vegetation, we intend to assess stocks and sequestration rates for salt marshes and seagrasses in the North-eastern Atlantic, in order to develop predictive models based on the environmental and biological parameters that determine them, including the reasons for their decline and how maximum historical levels can be restored,” explains Rui Santos.
A vital issue in this research is accounting for national flows of CO2 and other gases that contribute to the greenhouse effect, such as methane, so that the contribution of marshland and seagrass ecosystems can be included in our country’s national greenhouse gas inventory, a requirement Portugal is committed to under the UN Paris Agreement.
The researcher breaks down his investigation more simply, describing it as follows: “We investigate how the salt marsh and seagrass ecosystems contribute to our well-being, purifying the waters in coastal areas, providing fishing resources and helping mitigate global changes. These ecosystems remove nutrients from agriculture and urban effluents, serve as a maternity and nursery for many species and contribute to sequestering the CO2 that is released into the atmosphere.”
Levels of CO2 emissions in the atmosphere continue to grow, increasing the greenhouse effect. Ocean temperatures have been rising since the 1970s, having absorbed more than 90% of the excess heat trapped in the global climate system. In addition to reducing emissions, it is absolutely essential that we develop nature-based solutions which increase carbon sequestration, so that the global rise in temperature and ocean acidification does not reach potentially catastrophic levels. “Our research contributes to this target by optimising carbon sequestration by coastal ecosystems, which includes conserving these ecosystems and reversing their decline, which is resulting in carbon reserves deposited in their sediments hundreds or thousands of years ago being released into the atmosphere. We are also working to identify fertile areas in which to restore them,” says Rui Santos.
A fundamental component of this project is raising awareness, with the aim of improving the general public’s consciousness of the need to conserve these coastal ecosystems. As such, an Environmental Education Network on Coastal Ecosystem Services (REASE) was created, in which 14 Eastern Algarve school clusters of varying levels of education are participating. The activities carried out by the network include teacher training (over 80 teachers from 20 schools) and schools in the Algarve and Setúbal developing a blue carbon assessment project, involving more than 1,000 students. Easily linked to three Sustainable Development Goals, “Quality education” (Goal 4), “Climate action” (Goal 13) and “Life Below Water” (Goal 14), the RiaValue project aims to contribute to improving the quality of life of coastal populations and reducing CO2 levels in the atmosphere.
Rui Santos has aBachelor’s Degree in Biology, a PhD in Biology, a Post-Doc in Marine Ecology and is a researcher at the Centre for Marine Sciences (CCMAR). of the University of Algarve.
