Native oyster at Colne Point
Recovering Essex's native oysters
Underneath the stone-like appearance of the native oyster's grey exterior, there’s a lot to love about these marine molluscs.
Oysters are ecosystem engineers, passing water through their gill-like hairs and absorbing nutrients. By filtering our seas, sunlight is able to shine through the waters and help new life grow. Plants like seagrass can thrive in the clearer waters, helping us to fight climate change by absorbing carbon.
With one flat and one curved edge, they are able to cement themselves to shells, rocks and each other, creating oyster beds and reefs that provide food and shelter to other marine species.
Native oyster at Colne Point
Cultch deployment in the Blackwater, 2019 - ZSL
Recycled oyster shells, to create an environment for oyster larvae to attach to.
Did you know, a single oyster can filter and clean up to 200 litres a day?
Why do native oysters matter?
In the UK and Ireland, populations have declined by 95% and Essex holds one of the last remnant populations.
Native oysters, known as Colchester oysters, are integral to Essex's coastal heritage since Roman times. By the 19th century, over 200 million were sold annually in London. Despite this legacy, native oyster reefs are now among the most threatened marine habitats in the world due to overharvesting, disease, pollution, habitat loss, and invasive species.
Cultch deployment in the Blackwater Estuary - Jim Pullen
How Essex Wildlife Trust is restoring oysters
In 2011, Essex Wildlife Trust joined the Essex Native Oyster Restoration Initiative (ENORI). This collaboration of local oystermen, conservation organisations, government and scientists had one unifying goal: to restore self-sustaining populations of native oysters in Essex.
Since the group began, a Marine Conservation Zone of 284km2 has been designated to recover native oysters, a 200 hectare restoration box has been designated within this and over 1,000 tonnes of cultch (broken oyster shell) has been deployed to help oyster populations re-grow.