Mud Snail Translocation Led by Consultant Ecologist Daisy Fretwell

Brindle & Green recently completed a carefully planned mud snail translocation, led by Consultant Ecologist Daisy Fretwell, to support the conservation of this specialist species and ensure the successful establishment of a new habitat.

To prepare for the translocation, our Contracting team constructed a new pond in May, allowing it time to settle and fill naturally ahead of works. The site’s naturally clay-rich soils proved highly beneficial, enabling the pond to retain water without the need for artificial lining. This is particularly important for mud snails, which rely on soft sediment and burrow into the pond base during dry periods.

A preliminary scoping visit was undertaken in the beginning of July to better understand the existing conditions within the donor pond. During this visit, a small number of snails were carefully hand-translocated to the new pond. This allowed the team to identify the depth at which the snails were burrowed within the sediment. It was determined that the majority were located approximately four inches below the surface, closely associated with the root systems of soft rush (Juncus effusus), which dominated the donor pond.

Mud snails feed on decaying organic matter around plant roots, making it essential to translocate not only the snails but also their supporting habitat. The translocation methodology was therefore designed to move plants, sediment and snails together in each excavator pass. Each section of material removed ranged between 10 and 15 inches in depth, ensuring the inclusion of plant root systems and underlying clay substrate. Retaining this sediment structure is critical, as it provides the varied conditions required by mud snails throughout different life stages and seasonal changes.

The use of an excavator and dumper proved to be an effective and low-impact approach. Compared to hand tools, the excavator bucket’s blunt edge significantly reduced the risk of injury to the snails while allowing large sections of habitat to be moved efficiently in a single pass.

Following the successful transfer of the donor pond’s plants, sediment and snails, additional habitat enhancements were introduced at the receptor site. Two shallow scrapes were created adjacent to the new pond, with depths ranging from approximately 15 to 30 centimetres and gently sloping sides. These features were lined with clay from the donor pond and are expected to hold water seasonally and during periods of heavy rainfall.

The scrapes have been designed to diversify the habitat and provide further opportunities for mud snails to live and breed. They are expected to retain water during key breeding periods, typically between February and March, and again from October to November.

To support long-term habitat development, the new pond will be seeded in autumn, introducing a more diverse wetland and marginal plant community. This will enhance ecological resilience and create a more robust environment for the translocated mud snail population to establish and thrive.

This project demonstrates the importance of a carefully considered, habitat-led approach to species translocation, combining ecological expertise with practical delivery to achieve successful conservation outcomes.