Vertically-Suspended Environmental Enrichment Structures Improve the Growth of Juvenile Landlocked Fall Chinook Salmon
Alex J. Rosburg1, Brian L. Fletcher1, Michael E. Barnes2, Cody E. Treft1, Blaise R. Bursell1
Citation : Alex J. Rosburg, Vertically-Suspended Environmental Enrichment Structures Improve the Growth of Juvenile Landlocked Fall Chinook Salmon International Journal of Innovative Studies in Aquatic Biology and Fisheries 2019, 5(1) : 17-24.
Environmental enrichment is the use of structures or materials to create more natural or complex environments in hatchery rearing units. This study assessed the effects of two types of enrichment structures on the growth of juvenile landlocked fall Chinook salmon (Oncorhynchus tshawytscha) reared in semi-square tanks. The structures were vertically-suspended arrays of either five half-round polyvinyl chloride pipes or six golf balls affixed vertically on threaded rod (spherical enrichment). After 90 days, both enrichment treatments produced significantly greater weight gains than the unenriched control. Total fish length was significantly different among all three treatments, and was highest in fish reared with spherical enrichment. Individual weight, condition factor, and relative dorsal and pectoral fin length also differed between enriched tanks and the control, but did not significantly differ between enrichment types. The results of this study support the use of vertically-suspended enrichment structures to improve juvenile Chinook salmon growth during hatchery rearing.