Relationships between prices are of interest when testing for market integration as well as analyses of supply chains. A feature that has received little attention is that if two supply chains are linked by market integration at some stage, then the whole supply chain will be linked. Furthermore, the leading price in such a system can be in one supply chain and will not be revealed in market integration studies or analysis of a single supply chain. An empirical analysis is provided for the supply chains for salmon which originates in Norway and the United Kingdom and is then sold at retail level in France as smoked salmon. We find a high degree of price transmission in both supply chains, as well as integrated markets.