Abstract As urbanization globally drives mammals and carnivores into compact spaces, they will increasingly come into conflict with development and natural resource extraction pressures. The management of these populations is further complicated by difficulties in monitoring what are often rare and elusive species. We used local ecological knowledge (LEK) to collect data on the historical and current status of Eurasian otter ( Lutra lutra ) in Hong Kong as well as determine how local fish farmers and residents perceived management and conservation issues surrounding the species. We found evidence for small population size and decline in numbers and distribution over recent decades for L. lutra . Fish farmers had extensive and familiar experience with otters and expressed largely negative opinions about otter impacts on fish stocks but positive attitudes towards their conservation. However, if otters were to have real or perceived effects on livelihood, then opinions about their conservation were mixed and cautious. In the context of the Pearl River Delta megacity, biodiversity is under high threat from development and urbanization. We here show the value of LEK and human dimensions of conservation in balancing the complex challenges of managing land for both local livelihoods and environmental stewardship.