New research has uncovered evidence that extensive oyster reefs once existed all along Europe’s coastline, creating rich and diverse ecosystems that supported a wide range of underwater life. The study, led by the University of Exeter and The University of Edinburgh, used historical documents from the 18th and 19th Centuries to reveal the extent of these native oyster reefs. The researchers found evidence of reefs covering at least 1.7 million hectares, from Norway to the Mediterranean, which is larger than Northern Ireland. These reefs provided important habitats for almost 200 fish and crustacean species, as well as playing a role in stabilizing shorelines, nutrient cycling, and water filtration.
Today, oysters are mostly found as scattered individuals, and the reefs they once formed have largely disappeared. Restoration projects are underway across Europe, including initiatives like The Wild Oyster Project led by ZSL and partners, to bring back these vital ecosystems. However, to successfully restore oyster reefs on an international scale, more support from governments and decision makers is needed. Dr. Ruth Thurstan, part of the Convex Seascape Survey, emphasized the importance of understanding what marine ecosystems used to look like to inform conservation and recovery efforts. By combining historical accounts from various sources, researchers have been able to paint a picture of the past seas and the importance of oyster reefs in the marine environment.
Historical records, including newspapers, books, travel writing, and interviews with fishermen, have provided valuable insights into the economic and cultural significance of oysters in Europe. Dr. Thurstan noted that few people today have seen a flat oyster, which is native to the region, as the reefs they once built have disappeared. Oysters feature prominently in historical records, revealing their once prominent presence along the coasts of France, Denmark, Germany, the Netherlands, the Republic of Ireland, and the UK. Oyster reefs were slow to develop but were quickly destroyed through overfishing, leading to a fundamental restructuring of seafloors and the loss of thriving ecosystems.
The destruction of oyster reefs was a rapid process, resulting in the flattening of the seafloor and the loss of complex living reefs. Dr. Philine zu Ermgassen, an honorary researcher at the University of Edinburgh, highlighted the importance of historical ecology research in quantitatively describing the appearance and spatial extent of oyster reefs before their decline. These reefs were once thickly crusted with oysters and teeming with marine life, creating huge areas of biodiversity in European waters. The research team, consisting of over 30 European researchers from the Native Oyster Restoration Alliance, was able to paint a detailed picture of the past marine ecosystems thanks to historical records.
The study, partly funded by the European Research Council, sheds light on the extensive and diverse oyster reefs that once existed in European waters. By understanding the historical extent and importance of these reefs, researchers and conservationists can better inform restoration efforts to bring back these vital ecosystems. The destruction of oyster reefs through overfishing has had lasting impacts on marine biodiversity and ecosystem health. Restoring oyster reefs on a large scale is essential for preserving marine life and habitats, and requires collaborative efforts from governments, decision makers, and conservation organizations across Europe. Through historical accounts and research, we can appreciate the lost beauty and significance of oyster reefs and work towards their recovery for the benefit of both the environment and future generations.