Environmental monitoring of wild fish populations involves electrofishing, netting, and sampling — procedures that cause welfare harms requiring minimisation.
Environmental monitoring welfare represents a case where the purpose — protecting fish populations and their habitats through evidence — is inherently aligned with fish welfare, but the methods can cause harm. Electrofishing, when conducted by trained operators at correct settings, causes temporary immobilisation with usually rapid recovery. Poor settings or prolonged exposure can cause spinal injury and death. Minimising sample sizes, using anaesthesia during handling, reducing net crowding time, and adopting non-capture technologies where sufficient are all welfare improvements. Institutional animal ethics oversight is increasingly being applied to field fish sampling, improving welfare consideration as a matter of standard practice.