A scientist is evaluating a proposal for raising large numbers of fish in ocean pens for human consumption. As part of the evaluation, the scientist is designing a plan for investigating how the fish in the ocean pens might affect nearby ecosystems.

Which of the following is the most appropriate factor to use as the dependent variable in the experimental investigation?

The dependent variable is measured in an experiment. An experimenter who is investigating a fish farm is likely interested in the quality of the fish. The water temperature and type of fish would be examples of independent variables (manipulated variables). The amount of time it takes for a fish to digest a meal is unlikely to be important. The metabolic wastes however could affect nearby areas and is important to consider.