Results of the SeyCCAT/Nekton Research Expedition |26 May 2020
Dr Jeanne A. Mortimer
Marine plants in the deep waters of Seychelles help combat climate change
A project co-sponsored by SeyCCAT (Seychelles Conservation and Climate Adaptation Trust) and the Nekton Foundation for deep ocean exploration was completed in May this year with interesting findings from the deep waters of the outer islands of Seychelles.
In April 2019, Dr Jeanne A Mortimer joined the Amirantes Leg of the Nekton First Descent: Seychelles expedition. During that expedition, submersibles and remotely operated unmanned vehicles (ROVs) were sent down to explore at depths up to 300 metres. The focus of Dr Mortimer’s research was to determine at what depths marine plants occur in Seychelles. She was especially interested in seagrasses which are complex flowering marine plants. The findings of the study were quite exciting. Dr Mortimer and her team discovered that while live seagrasses only grew to maximum depths of around 30 metres, large amounts of dead and decaying seagrass material were being deposited at depth all the way down to well below 300 metres!
This finding is significant because it demonstrates for the first time how important seagrass in the Western Indian Ocean is to our planet. We already knew that seagrasses remove harmful greenhouse gases (especially CO2) from the atmosphere and store it in their leaves. What this new finding indicates, however, is that when the carbon trapped by the leaves of the seagrass sinks to the deepest reaches of the ocean, it is likely to never cycle back into the atmosphere again. In a time when climate threats like global warming and greenhouse gas emissions are changing our environments, there has been increasing support for preserving ecosystems such as seagrass meadows that help curb the trend of rising carbon dioxide levels.
Blue carbon ecosystems (i.e. seagrass beds, mangroves, saltmarsh) are among earth’s most efficient carbon sinks, burying carbon up to 40-times faster than tropical rainforests and locking away carbon in the ground, or in the deep sea, for hundreds of years. In addition to locking up carbon from the atmosphere, blue carbon ecosystems provide other important ecosystem services: they support fisheries, enhance biodiversity, and protect shorelines from erosion, extreme weather events and sea level rise.
With further research to help quantify just how much carbon the seagrass ecosystems in the Seychelles can capture, there is the potential for these areas to be internationally recognised for their carbon offset capabilities. If this can be done, the Seychelles can then ‘sell’ carbon credits to the Blue Carbon Market, and earn finances that can then be reinvested into restoring and protecting the long-term sustainability of these critically important ecosystems.
SeyCCAT finances marine scientific research projects. Its call for proposals will be open soon. Subscribe at www.seyccat.org for the latest updates.
Contributed by Dr Jeanne A. Mortimer and SeyCCAT
[Photograph of Jeanne attached]
