Salmon fishing in the severn: Judicial deference to regulatory judgments based on scientific assessments

Abstract

To claim that environmental law is heavily influenced by science is to make a rather trite assertion. Disputes about the probative value of scientific and technical evidence when used as the basis for a regulatory decision are therefore not uncommon. R. (on the application of Mott) v Environment Agency is an example of this phenomenon. In particular, the key issue was whether the Environment Agency had acted perversely (in judicial review terms) by relying on contested scientific evidence as the justification for imposing catch limitations designed to preserve salmon stocks in the river Wye. In finding for the Agency, the Court of Appeal restated and reaffirmed the established principle that decision makers ought to be afforded a wide margin of appreciation in such cases; a principle which reinforces the view that the courts are not an appropriate forum for the resolution of scientific and technical disputes. In commenting on this decision it is contended that the position of the courts in this regard has the potential to undermine the rationale of evidence-based decision making. However, it is impractical in most instances for a regulator to wait for a scientific consensus to emerge, particularly when acting to protect a threatened species. As a compromise solution, it is suggested that prior consultation at least has the potential to allow affected parties to scrutinise the available science, and offer alternative evidence prior to the final decision.