In this paper, we investigate the suppliers' allocation decisions between different product forms and markets using supply equations derived from a translog revenue function. This is of interest based on the hypothesis that fish processors and importers respond to changes in relative prices, diverting more fish into products or to markets where the price has risen. This can also at least partially explain the strong degree of correlation between prices of different product forms and markets that is observed in many seafood markets. An empirical analysis is carried out for cod for three main producers, Canada, Iceland, and Norway. The supply of cod exhibits substantial variation, and it is processed into a number of product forms. How the landings are allocated between product forms is then of substantial interest in itself, but also with respect to the influence of new species in the whitefish market, like pollock.