The UK’s first large scale offshore mussel farm is allowing shellfish reefs to return to parts of the seabed off England’s south coast for the first time in up to 150 years, a new study has revealed.
Researchers have spent the past decade examining the environmental impact of the farm, which was first established in Lyme Bay off the coast of Dorset in 2013.
In that time, the seabed beneath the farm’s ropes has begun to undergo a transformation as mussels from the lines are deposited on the seabed below.
This has seen it change from muddy sediment with limited biodiversity into reefs, which research has shown have the potential to benefit a number of commercial fish and crustacean species and the ecosystem more generally.
However, a historic map – recently uncovered by a Devon-based artist – has revealed this might in fact be a form of restoration rather than creating habitats never seen in the area before.
Dating from 1871, the French map describes a large area of the seabed – stretching from Torquay in the west and beyond Lyme Regis to the east – as being home to “rich shell beds”.
Scientists believe these are likely to have been oyster or mussel reefs that have long since been destroyed through the use of bottom towed fishing gear during the 20th century.
With such practices banned following the designation of the Lyme Bay Marine Protected Area (MPA) – and the mussel farm’s three sites located above the old shell beds – it is allowing the region to become home to shellfish reefs once more.
The map was part of the Marine Biological Association's collection but now donated to artist Hannah Wisdom. She shared it with scientists at the University of Plymouth, who have been working with fishing communities along the Lyme Bay coastline to monitor the impacts of the MPA since 2008, and the mussel farm since 2013.
Dr Emma Sheehan
