The level and depth of information provision required for making informed judgements over environmental options has remained troublesome in various contexts from individual choice through to international policy. In the valuation literature concern has been expressed for 'information bias' leading to distorted estimates of the worth of environmental entities (e.g. wildlife, ecosystems) because peoples intentions are formed during the valuation process by the information provided. Contending psychological models on the role of information and its relationship to ethical concerns are reviewed with respect to public decision processes over environmental entities. The robustness of pre-existing environmental preferences is then linked to ethical positions but their role is unclear. Empirical evidence is reported from a contingent valuation method study of coral reef biodiversity on the strong connections between informing and forming preferences and specific ethical beliefs regarding environmental entities.