Labrador sniffs out hundreds of invasive sea squirt colonies

A black Labrador in the Scottish Highlands has located hundreds of colonies of an invasive sea creature that can smother native wildlife. Sgiath’s work has earned her the International Fund for Animal Welfare’s Animal of the Year award.

Working with her owner, marine ecologist Dr Texa Sim, the six-year-old searches shorelines at low tide for carpet sea squirt. The organism can be hard to spot among seaweed or on structures such as pontoons and oyster cages. Sgiath has learned to recognise its scent and signal a find by becoming still or staring, rather than barking.

Sim developed the idea while working on a native oyster restoration project on Scotland’s west coast. Sgiath had trained in mountain rescue, and her success prompted Sim to test whether those scent-detection skills could also help marine conservation.

Carpet sea squirt can spread rapidly, harming wildlife and threatening shellfish farms. Once established, it can be difficult and expensive to control, and warming seas may help it spread further.

Dogs cannot solve that problem alone, Sim cautions. But detecting the invader earlier could give conservationists and site managers a better chance to respond before it becomes widespread.