Studies of how global change may alter food and feeding patterns. The prey spectrum may change, and should be quantified. Growth efficiency varies with type of food. This must be quantified for various stocks, and the balance of prey of different quality needs to be considered in global change models. Research should address the question of whether changes in net productivity will keep up with the changes in physiological requirements.
Much knowledge needs to be systematized into models.
Development of a full annual energy budget of cod is needed urgently. Commercial fisheries have marked effects on the population dynamics of many stocks, including all cod and haddock stocks. These effects must be included in meaningful models, but many consequences of fishing pressures on fish biology are poorly known. Features of the water masses other than temperature should be reviewed, including but not restricted to salinity. These data sets are often collected for specific purpose, usually stock assessments, and are greatly underutilized for other purposes, including global change impacts.