How Seychelles ocean plants can help combat climate change

View of Seychelles coastline

View of Seychelles coastline

At low tide, Errol Renaud can view the seagrass meadows on the ocean floor from his shore house on Mahe island in Seychelles.

He is one of many locals who oppose a hotel development project that could reclaim the area.

“There’s a lot of seagrass meadows here and a lot of fishermen in this area who put their fish traps there. So they rely on this area,” says Mr. Renaud.

There are currently two land reclamations near his home that are disturbing the seagrass meadows that act as a barrier against rising ocean levels and extreme conditions.

“This reclamation earlier during the monsoon means a lot more sand is coming to one side and we are seeing much higher waves.

“With climate change, we’re losing a lot in this region,” he says of the region where he has lived for more than two decades and where he sees his land being increasingly filled with rising water levels.

Coastal wetlands such as seagrasses, mangroves, swamps and marshes have many environmental benefits. They are seen as one of the most effective solutions in tackling global warming, as well as defending against rising waters and harsh weather conditions caused by climate change and promoting biodiversity.

A study published in the Royal Society’s leading biological research journal says seagrasses capture carbon 35 times faster than rainforests. If left undisturbed, they can hold carbon for thousands of years, much longer than terrestrial plants. Thus, they act as a natural carbon sink.

They account for 10% of the ocean’s total carbon burial, although they cover less than 0.2% of the ocean floor, according to a report in the scientific journal Nature Geoscience.

But according to researchers in the US, the total amount of seagrass is declining, putting this sea plant at risk of imminent extinction.

View of Seychelles coastline

Seychelles is extremely vulnerable to the effects of climate change

At the COP27 climate conference in Egypt last month, activists and international organizations called for a greater effort to conserve and use these nature-based solutions to combat climate change.

A country of 115 low-lying islands, Seychelles is extremely vulnerable to the effects of climate change, yet there are enough seagrass meadows around these islands to fill hundreds of thousands of football fields.

The government has committed to protecting half of seagrass meadows and mangroves by 2023 and 100% by 2030.

This year it became one of the first to accurately map entire seagrass ecosystems nationwide.

Samples from seagrass meadows and mangroves are analyzed to calculate how much carbon they store over time. Such carbon, and its residue, held in coastal wetlands is referred to as “blue carbon” rather than “green carbon” retained in terrestrial plants.

Drone view of a seagrass

Seychelles hopes to expand seagrass meadows to store more carbon

Behind the mapping and analysis is a project by SeyCCAT, an independent trust. It provides the results for the government to use. He also raised public awareness, primarily by educating school children and university students about seagrass meadows.

Countries often use satellite imagery to map seagrass meadows, but this is not reliable and can be confused with algae such as seagrass and kelp, which differ because they do not have roots connecting them to the seafloor. The SeyCCAT project undertook fieldwork using remote sensing technology and took sediment samples to reliably map grasslands.

In a lab at the University of Seychelles, researchers break down about 2,600 samples to extract the carbon.

“We want to understand how much carbon has been stored in the seagrass meadows over the past few years to inform the government that wants to determine how much carbon content is in the seagrass meadows around Seychelles,” says Jerome Harlay. The scientist on the project.

“We want to use these numbers to mitigate climate change. How much carbon can they remove from the atmosphere compared to what our human activities add.”

Jerome Harlay takes underwater photo of seagrass

Jerome Harlay takes a hands-on approach to mapping seagrass

This analysis means that Seychelles could be the first country to report its blue carbon stocks to the UN as part of its greenhouse gas emissions report. And it will be able to show how these stocks are helping the country meet the Paris Agreement contributions to keep global warming at 1.5 degrees Celsius.

After mapping ecosystems, the government can define policy strategy, ongoing management and legal protections for them. This is the next phase of the SeyCATT project that it will work with the government to achieve.

Knowing what true blue carbon stocks are, Seychelles will be able to trade with other countries that want to offset their emissions.

According to Denis Matatiken, chief secretary of the Seychelles Ministry of Agriculture, Climate Change and Environment, carbon trading could be one of several economic benefits of conserving seagrass.

“The Seychelles depend heavily on fishing and tourism. They are considered pillars of our economy,” Matatiken says.

“However, the foundation of these pillars is the environment. So protecting the environment means that those pillars can survive. This is how we can grow as a small island nation.”

Erol Renaud

Errol Renaud thinks seagrass could make as much money as the proposed hotel

Preethi Sushil Nair of the United Nations Development Program in Seychelles says this project in Seychelles can be a guide for other parts of the world as countries continue to make commitments on how to mitigate global warming.

“In terms of scaling up, this is possible because we know the solutions are in nature.

But he says it’s essential to have “tools in terms of data, analytics, maps” for other countries to formulate their own policies and help tackle climate change.

“And as long as there’s that commitment and community involvement, then there’s a great success rate.”

Returning to the coastal community, Mr. Renaud sees the conservation of seagrass meadows and the use of blue carbon stocks as the only benefits: “If we look at the carbon potential of seagrass meadows in our area, about 50 hectares, we could offset the cost of the hotel. The project would have saved the economy.”

While Seychelles has a long way to go to truly benefit from its blue carbon stocks, it offers a solution that others can follow to reduce global warming.

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