A Precautionary Approach to Welfare in Wild Fish Research and an Adaptable Framework to Inform Anaesthetic and Immobilisation Method Selection

For researchers and professionals working with wild fishes, the decision to choose a particular anaesthetic or immobilization technique can be fraught with uncertainty and conflicting guidance over what method might be most appropriate for their research setting/context and the welfare of fish being handled. There are diverse perspectives relating to how researchers, ethicists, and other personnel invested in fish welfare approach this subject, including if/to what extent certain responses observed in fishes are informative about individual welfare states, or whether certain philosophical tools used in welfare-related decision-making (particularly the precautionary principle) are actually helping or hindering efforts to improve welfare from an evidence-based lens. Here, the authors provide overviews of some key elements of anaesthesia/immobilization technique selection and fish welfare more generally, and introduce a precautionary principle of the authors’ own formulation relating to the complexities of refinement of research protocols involving wild fish. Next, the authors propose and describe a framework that can be used to help select the most suitable anaesthetic or immobilization technique for a given research effort in line with refinement of research methods. This framework also specifically incorporates consideration of complex realities inherent to many research projects on wild fish and allowances for critical context-specific considerations. The authors include discussions and examples largely from a North American (particularly Canadian) lens, but many of the core concepts illustrated are or may become applicable in other jurisdictions as scientific knowledge, laws, and ethics guidelines continue to evolve. The authors then explore the basis of the proposed precautionary principle and its connection to the framework in greater depth, along with some potential criticisms. The authors conclude with recommendations for future work relating to significant knowledge gaps and challenges relating to information access and consistency among researchers, governments, and other relevant participants or supporters of wild fish research.