This paper investigates Japanese consumers’ willingness to pay for Marine Stewardship Council (MSC) ecolabelled seafood using a sealed bid, second price auction. Participants in an experiment in Tokyo were provided varying degrees of information about the status of world and Japanese fisheries and the MSC program in sequential rounds of bidding on ecolabelled and nonlabelled salmon products. A random-effects tobit regression shows that there is a statistically significant premium of about 20 per cent for MSC-ecolabelled salmon over nonlabelled salmon when consumers are provided information on both the status of global fish stocks and the purpose of the MSC program. This premium arises from a combination of an increased willingness to pay for labelled products and a decreased willingness to pay for unlabelled products. However, in the absence of experimenter-provided information, or when provided information about the purpose of the MSC program alone without concurrent information about the need for the MSC program, there is no statistically significant premium.