German hairy snails vanishing from River Thames in London

The German hairy snail (Pseudotrichia rubiginosa) is a small mollusk distinguished by its hairy shell, commonly found along the River Thames in England and other regions. Scientists suggest that the snails hair-like structures help it cope with the damp riverside conditions by managing excess moisture. This adaptation allows the snails mucus to become stickier, helping it cling to slippery surfaces and feed on plants along the riverbanks.

Despite its resilience, the German hairy snail is among the most threatened mollusks in the UK. Its natural habitats along the Thames have shrunk, leaving only fragmented areas suitable for survival. In response, conservationists, rewilders, and citizen scientists in London have begun surveys to monitor the snails population and better understand its local distribution.

These surveys are vital for assessing the snails condition and guiding conservation strategies, helping protect both the species and the green spaces of London for future generations, said Joe Pecorelli, Freshwater Conservation Programme Manager at the Zoological Society of London.

Fossil evidence indicates that the German hairy snail has been present in the UK since at least the Stone Age, possibly even the last Ice Age, when Britain was connected to mainland Europe and the Thames linked to the River Rhine. Pecorelli noted, This small snail has been a part of our riverbanks and wetlands for thousands of years, yet today it is extremely rare, likely confined to a few sites along the Thames.

The species is also found in other parts of Europe. A 2013 assessment highlighted populations in eastern Russia, Baltic islands, and Germany, where the snail is classified as endangered. Mapping the snails distribution is crucial for conservation and could inspire efforts to restore and protect Londons river habitats.

Healthier waterways would not only support the German hairy snail but also benefit other native wildlife, including European eels, seals, and short-snouted seahorses, which inhabit Londons rivers.

Author: Sophia Brooks