Native Oyster Reintroduction
The Project
Native oysters
Native oysters (Ostrea edulis) otherwise know as European Flat oysters are a bivalve mollusc. They are sessile meaning they do not move and feed by filtering particles from the water column. Native Oysters were once common around the UK coast but due to over fishing and reduced water quality their population has dropped by 95% around the UK coast over the last 100 years. Record show there was once a active oyster fishery in the Tees estuary as late as 1940. Our aim is to return this lost species to our coastline
Why Restore Oysters
As well as bringing back a species that has been lost to our coastline, Oyster restoration brings with in many potential benefits. Oysters are filter feeding meaning they work as ocean vacuum cleaners removing particles from the water column making the oceans cleaner. A single oyster can filter up to 200L of water a day. This is about the volume of a bath tub. Oyster also form large 3D reef structure by growing on top each other. This creates amazing habitats for juvenile fish, crabs, lobsters and many more species. Because of they're benefits oyster have been identified as a key species in the UN decade of restoration
Native Oyster Nurseries
Our first stage in bringing oyster back to the estuary was to install an oyster nursery into Hartlepool Marina. This consists of 20 cages each holding over 600 adult Oyster. Each year these oyster will reproduce releasing millions of larvae into the water. These will hopefully find a place to settle and start growing along the Tees Coastline. In the future we hope to place a mix of shell and gravel (cultch) into the estuary to provide a habitat for the larvae to settle
These nurseries also provide an excellent refuge for animals living in the marina. Once a month we monitor the nursery and have found over 25 different species living in and around the cages.
Due to the success of our first nursery in April 2024 we installed a second nursery into Hartlepool docks. We will monitor these cages monthly to allow comparison to the Marina site. Eventually we aim to place cages directly into the estuary channel.
Spatting Pond
The next phase in our oyster restoration project is to use a spatting pond. In summer 2024, adult oysters were hung in the top of the pond where they started to spawn. The bottom was lined with shell. Larvae from the adult oyster settled on the shell and developed into spat. Once the baby oysters (known as spat) on the shells are large enough they can then be deployed out to sea to start a reef.
We will be providing the Wild Oyster Project, Tyne and Wear, with spat on shells to deploy on to their reef site off the coast of Sunderland. Our aim is to also have a reef in the Tees estuary or surrounding coast that we can stock with spat on shell from our spatting pond.
Gallery
Project Partners and Funders
