Otter population monitoring requires survey methods that minimise disturbance. Understanding non-invasive survey techniques helps researchers and citizen scientists monitor otter welfare.
Otter survey methods have welfare implications when they involve physical capture. Catch-and-release trapping — used for marking individuals and collecting physiological data — imposes handling stress on wild animals. Welfare protocols for otter trapping include minimum check times (traps must be checked daily), provision of food and water in traps, and prompt processing and release. Non-invasive alternatives — camera traps, DNA from spraints — are welfare-preferable and increasingly sophisticated. Citizen science contributions through otter spotting records contribute meaningfully to population monitoring without any welfare cost to individual animals.