The value of Jersey’s seagrass

It’s now recognised that coastal ecosystems play an essential role in fighting climate change. PhD student Anna Smith is embarking on a three-year study looking at blue carbon processes in Island waters. By Caroline Spencer

Seagrass is one of Anna Smith’s favourite marine species. It occupies just 0.1% of the sea floor but is responsible for 11% of the organic carbon buried in the ocean. It captures carbon at a greater rate than tropical forests.

‘Seagrass has always been underappreciated, and it’s always been the underdog compared to coral reefs and rainforests,’ she said.

A recent study published in the journal Frontiers in Plant Science reported that the UK has lost more than 90% of its seagrass meadows. And Jersey’s seagrass has also been under threat.

‘A disease killed off much of Jersey’s seagrass, but it is coming back,’ Anna explained. ‘It would be interesting to have seagrass planting here but a lot of people say it’s not suitable. I don’t know if it would be possible actively to restore it, rather than letting it grow back by itself, very slowly.’

Anna (24), who hails from Kent, is a PhD student with the Jersey International Centre of Advanced Studies (JICAS). Her study of blue carbon processes is backed by a £20,000 grant from the Jersey Community Foundation.

Blue carbon is the carbon stored in coastal and marine ecosystems and its importance in mitigating climate change is becoming increasingly recognised.

‘Simply put, I’ll be looking at how much blue carbon Jersey has,’ Anna said. ‘I want to understand better how the processes of blue carbon can maximise the potential ecological, environmental and social value of the sea. This includes demonstrating the decomposition value of the carbon-depositing habitats found in the Normandy-Brittany Gulf by replenishing and restoring the marine ecosystems of valuable species such as seagrass, maerl beds and bivalve populations.

‘Probably one of Jersey’s biggest sequesters of blue carbon is macro algae. But macro algae don’t necessarily draw carbon straight into the oceanic sediment because they get taken elsewhere by the currents in the sea. We need to find out where that carbon is deposited.

‘We’re trying to find out how much macro algae is in the sediment basins in the Normandy-Brittany Gulf. We need to really protect these carbon-rich basins as well as the algae, seagrass and maerl beds.’

Anna will spend three years carrying out her research, some of which will involve diving and collecting samples of seagrass. It will also involve taking core samples to find the environmental DNA, i.e. the percentages of algae in the ocean floor. Additionally, and more importantly, isotope analysis will show whether the carbon is actually staying there.

The world has woken up to the importance of terrestrial carbon and the role that rainforests play in mitigating climate change. Blue carbon is now increasingly to the fore. 83% of the global carbon cycle is circulated through the ocean.

‘Blue carbon is becoming more popular because we don’t have enough land to sequester enough carbon,’ Anna said. ‘For an island like Jersey, we have an opportunity to protect carbon-rich areas in the ocean and also get money from it, through carbon offsetting programmes.’

JICAS is a postgraduate research centre specifically for island communities, and Anna believes that many island nations can lead the way in sequestering blue carbon.

‘With my study, I want to prove that certain areas of Jersey waters are rich in carbon and demonstrate that it’s not just worth protecting for biodiversity’s sake, but also because you can get money from it.’

Anna, who has a degree in Biological Sciences, completed a project on seagrass in Anguilla as part of her Master’s in Island Biodiversity and Conservation. She is looking forward to liaising with various agencies in Jersey, such as Blue Marine Foundation and Jersey Marine Conservation.

‘It was only on my Master’s project that it dawned on me that if seagrass sequesters the same amount of carbon if not more than tropical rainforests, why aren’t we focusing on it more? 'The rhetoric that I always hear is that to put blue carbon on the same level as terrestrial carbon, and to get the carbon on the market to be sold as carbon credits and make it profitable, we need more research. I think that’s the key and that’s what really pushed me to go into it. Research is fundamental for policymaking.

‘I really hope my project does make a difference in the future.’

*JICAS offers a Postgraduate Masters Programme in Island Biodiversity and Conservation in partnership with the University of Exeter. A consortium of world-leading academics has been drawn from institutions across three continents to come together in Jersey to produce a unique programme of research-led study. “ It was only on

my Master’s project that it dawned on me that if seagrass sequesters the same amount of carbon if not more than tropical rainforests, why aren’t we focusing on it more?