Invertebrates
European Flat Oyster
Ostrea edulis · also called native oyster
In a sheltered estuary, a European flat oyster sits cemented to a stone, drawing in water and filtering it slowly, part of a reef that is being rebuilt.
Overview
The European flat oyster, Ostrea edulis, is a bivalve of sheltered coastal waters and estuaries across the north-eastern Atlantic and the Mediterranean. Its brooded larvae, sex changes, and past reef-building make it one of the most important and most threatened shellfish of Europe.
A reef-builder brought back
Where flat oyster reefs once cleaned the water and sheltered fish, projects around Britain and Europe are now putting oysters and shell back in the sea to restore them.
Status
Not Evaluated by the IUCN, but beds have declined drastically.
European Flat Oyster: common questions
Why is the European flat oyster threatened?
Its beds have declined drastically across Europe because of overfishing, disease, pollution, and invasive species.
How does a flat oyster breed?
Females keep their fertilised eggs in the mantle cavity and release larvae into the water after about ten days.
Why are oyster reefs restored?
Reefs filter and clean the water and provide shelter and food for many other animals, so restoration helps whole ecosystems.
Where is the European flat oyster found?
It lives in sheltered coastal waters, estuaries, and shallow seabeds of the north-eastern Atlantic and the Mediterranean.