Datasets for tank colour preference and tank aggression displayed by coho salmon kept in closed containment aquaculture systems

100 coho salmon were randomly assigned to groups of 10 and housed in 10 different recirculating aquaculture tanks (tank 1-10). The interior sides and base of each of the experimental tanks were lined with laminated paper varying in pigmentation. Each tank was split into two to provide fish a choice of background colour. Preference tests were conducted between (a) black versus white, light grey, dark grey and patterned tank backgrounds and (b) blue versus white, light grey, dark grey, and black tank backgrounds. The positions of the fish in each tank were video recorded from above. The fish in each tank were recorded for a total of 10 min. Videos were scored at 30-s intervals to determine the number of fish on each side of the tank. Videos were scored continuously for aggressive acts throughout each 10-min trial. Datasets are provided for the black-trial preference tests (number of fish located on the black sides of the tanks for each comparison colour), blue-trial preference tests (number of fish located on the blue sides of the tanks for each comparison colour), and tank aggression (number of aggressive acts occurring on each side of the tanks).