Photo credit: Henriette Grimmel
Researchers from the University of Oxford have finalised and shared results from an extensive seagrass distribution assessment undertaken within Seychelles’ Exclusive Economic Zone (EEZ). Dr. Gwilym Rowlands, an Earth Observation Scientist at Oxford, led this research in partnership with several local and international organisations, namely the Ministry of Agriculture, Climate Change and Environment, the Seychelles Conservation and Climate Adaptation Trust, the University of Seychelles, the Island Conservation Society, the German Aerospace Agency (DLR) and others.
This research project, titled the Seychelles Seagrass Mapping and Carbon Assessment Project, was initiated in 2020. It aligns with the Seychelles Government’s commitment to safeguard 50% of its blue carbon ecosystems, including mangroves and seagrass meadows, by 2025 and achieve 100% protection by 2030. The commitment was made as a Nationally Determined Contribution (NDC) under the Paris Agreement with the goal of including these seagrass ecosystems within the Seychelles’ National Green House Gas Inventory (NGGI).
In supporting the country’s target, the project was designed, first to identify the distribution and extent of seagrass habitats in Seychelles’ EEZ. This would then allow the quantification of the amount and rate at which these habitats store carbon. Using satellite imagery and meticulous ground surveys, the research team mapped 159,920 ha (1,599 km2) of seagrass across the 1.36 million km2 of Seychelles’ Exclusive Economic Zone (EEZ). This vast area, equivalent to 29,000 football fields, was identified as a significant resource capable of storing 18.9 million tonnes of organic carbon, amounting to 69 million tonnes of C02.
When drawing comparisons, the findings indicated that these seagrass ecosystems are storing CO2 at a rate of 510 000 tCO2e per year, nearly the same as the annual emissions from the Seychelles energy sector and almost three times the emissions from the transport sector. Further findings indicated that most seagrass habitats in Seychelles waters are around the Mahe Plateau Rim and the Amirantes Bank, with these areas inhabiting 32.9% and 30.3% of Seychelles seagrass, respectively.
Whilst looking at the distribution of seagrass within the Seychelles Marine Spatial Plan (SMSP), the researchers were able to identify that 99.5% of Seychelles seagrass habitats are luckily found within High Biodiversity Zones and Medium Biodiversity and Sustainable Use Zones as well as pre-SMSP protected areas. However, they also raised the concern that the most diverse seagrass meadows around Praslin and the Au Cap region, where at least seven species have been recorded, are located unfortunately within Multiple Use Zones and, therefore, do not occur within an existing protected area.
Nonetheless, the results birthed from this extensive study, which included the work of 50 predominantly Seychellois researchers and spanned over 20 institutions, have now quantified the importance of seagrass as a blue carbon ecosystem for the country. The report, therefore, provides the robust science needed to inform policy decisions regarding seagrass protection in Seychelles.
Download the full report for more information.