The cases are rehydrated, categorised and counted – which helps scientists better understand the marine species.
Mike McDonnell, who runs the group, said getting into nature had helped members make valuable connections and gain in confidence.
“We’ve got people that maybe had quite severe anxiety, maybe hadn’t left the house for a couple of years, especially coming off the back of the pandemic, forming friendships,” he said.
Lancashire Wildlife Trust’s The Bay Group recently won a national award for its work and was recognised at the Marsh Volunteer Awards for Marine Conservation.