The Darling River snail, a critically endangered mollusc once feared extinct, was spotted at a weir on the Barwon River near Walgett in western New South Wales.

Survey teams recorded a tiny colony of about 50 living snails more than 700 kilometres upstream, a location where the species had not been seen for decades.

Since the 1960s, the construction of weirs and irrigation systems has been considered a contributing factor to the snail’s decline, as altered flows reduced natural habitats.

Professor Martin Mallen‑Cooper said the discovery shows the snails can survive in artificial habitats created by weirs, highlighting a surprising adaptation to human‑made structures.

Aboriginal rangers confirmed the discovery and research and repopulation efforts are now underway, aiming to protect the new colonies and possibly re‑introduce the snail to other parts of its historic range.