Why do people litter? And what can we do about it? These are questions we grapple with daily as we continue to encounter discarded picnics, submerged shopping trolleys and dumped household waste in and around our precious waterways. On the latest episode of Once Upon a River, we chat with environmental phycologist Rob Curnow has also been trying to answer these questions for over 20 years, while working on campaigns to try to understand and change people’s disposal behaviours.