We are on a mission to discover where colonies of native flat oysters (Ostrea edulis) are or were present in the UK. Here's a handy guide to help you identify them!

This image shows an intertidal native oyster (left) with a pacific oyster (right).

Native oyster and pacific oyster

If you have come across live native oysters or shells in the wild, please record the details in our online form. This information will help inform plans to protect existing colonies and restoration projects.

Native oysters can be difficult to spot amongst their surroundings and can be confused with pacific oysters (Crossostrea gigas) which we are also interested in. This quick start picture guide should help you get tuned in to what you are looking for including competing organisms like the slipper limpet (Crepidula fornicata) and one of their predators, the oyster drill (Ocenebra erinaveis). 

Native oyster (Ostrea edulis)

Native oysterBoth sides of the oyster are relatively flat, while the shell is more smooth and round than a pacific oyster.

Juvenile native oysterJuvenile native oyster next to dive computer for scale and depth – this sort of image is really useful for our research.
Native oyster on wreckageNative oysters on wreckage of ship's boiler in 30m of water.
Native oyster under pierNative oyster in shallow water under a pier.
Native oyster amongst seagrassNative oyster in shallow water under a pier.
Operation OysterNative oysters inside a shipwreck in shallow water.
Native oyster covered in spongeUpside down native oyster inside a wreck covered in sponges.

Intertidal native oysterIntertidal native oysters.

Native oyster intertidal rockpoolIntertidal native oysters.

Pacific oyster (Crossostrea gigas)

Pacific oysterA pacific oyster has a much more elongated shape than the native oyster, with one side slightly convex while the other is flatter.

Pacific oysters are often found intertidally.

Pacific oyster on rockPacific oyster settled on a rock. 

Pacific oyster shapes

Pacific oyster settled to piling

 Slipper limpet (Crepidula fornicata)

 Slipper limpet shells Slipper limpet shells

 Oyster drill (Ocenebra erinaveis) 

Oyster drill Oyster drill

Images supplied with thanks to Dr Luke Helmer and Andy Hunt. 

Record your oyster findings

Please fill in the online form to record your sightings of UK native oysters and non-native cousins.

Record your oysters

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