Last updated: 16 December, 2024 @ 14:40
A new study has found that European flat oysters once formed extensive reefs along much of Europe’s coastline.
Based on documents from the 18th and 19th centuries, the study reveals that European flat oysters, also know also native oysters, formed large reefs of both living and dead shells.
Researchers found evidence of reefs existing from Norway to the Mediterranean, covering at least 1.7m hectares – an area larger in size than Northern Ireland.
Oysters play a vital role
The research was led by the University of Exeter and the University of Edinburgh.
The University of Exeter says that in addition to creating homes for the almost 200 recorded fish and crustacean species, the oysters also played a vital role in stabilising shorelines, nutrient cycling and water filtration – with a single adult oyster filtering up to 200 litres of water a day.
It said that restoration projects are under way across Europe – and small-scale habitat restoration, such as The Wild Oyster Project, led by ZSL and partners, are ‘key stepping stones to the return of these vital ecosystems on an international scale’.
However, it said that restoration efforts ‘need to be scaled up with support from governments and other decision makers across the continent’.
‘Few have seen a flat oyster’
“Human activities have affected the ocean for centuries,” said Dr Ruth Thurstan, from the University of Exeter and part of the Convex Seascape Survey, an ambitious five-year project examining ocean carbon storage.
“This makes it difficult to discover what our marine ecosystems used to look like, which in turn hampers conservation and recovery.
“Few people in the UK today will have seen a flat oyster, which is our native species. Oysters still exist in these waters, but they’re scattered, and the reefs they built are gone,” said Dr Thurstan.
“We tend to think of our seafloor as a flat, muddy expanse, but in the past many locations were a three-dimensional landscape of complex living reefs – now completely lost from our collective memory.”
Read the oyster research paper
The research team was made up of more than 30 European researchers from the Native Oyster Restoration Alliance.
The paper, ‘Records reveal the vast historical extent of European oyster reef ecosystems’ can be accessed here.