Essex Seagrass Project

Seagrasses are the only flowering plants able to live in seawater and pollinate while submerged. They are found in shallow waters and often grow in large groups giving the appearance of terrestrial grassland – a lush underwater meadow.

Seagrass meadows are a biodiversity hotspot. This means they support a diverse ecosystem from spawning and nursery sites for fish, to providing food and shelter for marine mammals, waterfowl and tiny invertebrates. Their roots stabilise the sediment and as they absorb nutrients they clean the surrounding seawater. Seagrass is also vital in our combat against climate change: one hectare of seagrass may store two tonnes of carbon dioxide (CO₂) a year and hold it for centuries. Healthy seagrass also supports commercial fisheries.

Although seagrass has suffered severe declines and continues to be put under multiple pressures, we still have vital patches of seagrass meadows along our coastline, including off Two Tree Island nature reserve in the Thames, St. Lawrence on the Blackwater and off Wrabness nature reserve on the Stour. Whilst there are over 70 species of seagrass globally, only two are found on the Essex coast. Common eelgrass (Zostera marina) and dwarf eelgrass (Zostera noltei) occupy similar areas in the shallows and intertidal area, but dwarf eelgrass is the most common in Essex.

In the UK, we have lost half of our seagrass meadows since 1985; and locally, studies have shown that meadows in the Stour and Orwell estuaries are at just 2% of their 1973 extent.

There are many factors that have led to the decline of seagrass: from physical pressures such as anchoring, mooring, bait digging and trampling; to eutrophication (excessive nutrients in the water system leading to algal blooms), pollution and climate change. They were also severely affected by a disease in the 1930s.

The Essex Seagrass Project aims to protect seagrass meadows and inform their future restoration and management in Essex.

Part of this project delivers the ReMEDIES Save Our Seabed project in Essex. The Essex Estuaries Special Area of Conservation (Jaywick to Shoebury) is the location of one of five projects in southern England that aim to reduce the negative impact of recreational boating activities, such as mooring and anchoring on current seagrass meadows. Essex Wildlife Trust is working with Natural England and other ReMEDIES partners to develop and deliver this project. 

Through the project, we are expanding our research to cover the entire Essex coastline to include both current and historic areas of seagrass. We are training citizen scientists to record recreational activities around the coastline to monitor and gain a better understanding of the exact pressures facing our coastal species. We will also be raising awareness of the importance of seagrass habitats and will work with key coastal communities, stakeholders and water users.

We are also working with Project Seagrass to restore Essex’s seagrass. This includes conducting extensive surveys on our existing seagrass to learn about its properties and characteristics, as well as trialling restoration techniques such as transplants with a view to expanding this at various sites along Essex’s coast.  

Now you know how vital seagrass is and where it's found, you might be wondering what you can do to help us protect it. By following these three simple steps, you can help us keep our seagrass meadows safe: