Use of different colours of vertically-suspended structure during the hatchery rearing of juvenile landlocked fall Chinook salmon (Oncorhynchus tshawytscha, Walbaum)

This study investigated the effects of coloured structures on the growth of juvenile landlocked fall Chinook salmon (Oncorhynchus tshawytscha, Walbaum) during hatchery rearing. Structures consisted of an array of four aluminum angles painted one of four colours: Silver, red, black and green, which were vertically suspended in circular tanks. After 25 days, mean total lengths and weights of individual salmon reared in tanks with the green arrays were significantly (P 0.05) among the colour treatments. Final total tank biomass and gain were also not significantly different (P > 0.05) among the colour treatments. The results of this study indicate that structural colours could be considered to maximize juvenile Chinook salmon growth during hatchery rearing.  Key words:  Chinook salmon, colour, Oncorhynchus tshawytscha, hatchery rearing.