A severe decline in landings of haddock (Melanogrammus aeglefinus) in the northeastern U.S. has resulted in prices similar to those of salmon, and market reliance on imports. This creates an opportunity for haddock culture in Maine, utilizing the facilities already in place for salmon aquaculture. The suitability of haddock for net-pen culture will be determined by seeking answers to the following questions: 1) Is the growth rate of haddock on artificial diets comparable to that of salmonids; 2) Are modified salmonid net- pens suitable for rearing haddock; and 3) Can haddock and salmonids be reared together. Adult haddock will be captured during spring 1990 and transported to modified salmon net-pens in Eastport, Maine. There growth on different diets will be measured and adaption to the net-pens and interaction with salmon assessed. Production of haddock in Maine would allow net-pen growers to compete with those in Europe, where commercial culture of other whitefish is likely in the next few years. Maine-grown haddock could provide an alternative to the current imports of wild haddock from Iceland and Canada.