Journals and charts reveal scale of oyster reef decline

Just a handful of natural oyster reefs, measuring at most a few square metres, cling precariously along European coasts after centuries of overfishing, dredging and pollution.

- Steven Morris

Now a study led by British scientists has revealed that reefs were once as high as a house and covered at least 1.7m hectares (4.2m acres) from Norway to the Mediterranean.

Dozens of researchers pored over government records, nautical charts, fishery reports, customs documents, naturalists' accounts, scientific journals and newspapers from the 18th, 19th and early 20th centuries to understand the spread of the European flat oyster (Ostrea edulis).

They found vivid 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 high in the Black Sea.