Europe’s exhausted oyster reefs ‘once covered area size of Northern Ireland’ | Study uncovers vivid and poignant accounts of reefs as high as houses off countries including UK, France and Ireland

From the article: Only a handful of natural oyster reefs measuring at most a few square metres cling on precariously along European coasts after being wiped out by overfishing, dredging and pollution.

[A study](https://www.nature.com/articles/s41893-024-01441-4) led by British scientists has discovered how extensive they once were, with reefs as high as a house covering at least 1.7m hectares (4.2m acres) from Norway to the Mediterranean, an area larger than Northern Ireland.

The study involved dozens of researchers poring over government records, nautical charts, fishery reports, customs documents, naturalists’ accounts, scientific journals and newspapers from the 18th, 19th and early 20th centuries to piece together the spread of the European flat oyster (Ostrea edulis).

They found vivid – and poignant – accounts of often sprawling reefs at 1,196 locations off countries including the UK, France, Ireland, Denmark, Spain, Germany and the Netherlands. One report from a scientific article mentioned oyster reefs reaching 7 metres in height in the Black Sea.

Ruth Thurstan from the University of Exeter, the joint lead author of the report, said she was “blown away” by the extent of the reefs. “I knew that oysters used to be caught in huge quantities, so we suspected that these reefs could be large, but to find information that evidenced such coverage of reefs, amazed me.

I am a huge fan of oyster restoration efforts. They are an amazing natural filter for our waters.