The introduction of a resident strain of yearling rainbow trout into the Sumallo River was evaluated during summer to fall, 1989. A fence was operated to assess migration and fish were enumerated in the stream by use of underwater counts supplemented with electrofishing. A small proportion (9 %) of the 7000 fish that were stocked, migrated from the Sumallo into the Skagit River. Significant numbers of wild rainbow, comprised of mainly juveniles, also migrated suggesting that the Sumallo is providing recruitment to Ross Reservoir. Underwater census of hatchery and wild trout was not useful as a population enumeration technique because most fish moved deep into cover in association with the cool (10 C) summer temperature regime. Sampling of stocked rainbow trout in the fall indicated that growth was meagre. Further stocking should be deferred until the 1989 cohort, as well as a returns from the 1988 stocking of Skagit migrant strain, are more intensively assessed in 1990.
Slaney, Pat A., Godin, Theresa I.. 1989. Sumallo River Stocking Evaluation: Progress 1989. BC Ministry of Environment. Fisheries Project Report. RD25
Topic: Fish and Fish Habitats
Keywords: British Columbia, BC, Fraser Valley, Sunshine Valley, E. C. Manning, Okanagan, Similkameen, Skagit, Rainbow, migration, juvenile, hatchery, wild, trout, angling, sportfishing
Other Identifier: FPR RD25
To copy the URL of a document, Right Click on the document title, select "Copy Shortcut/Copy Link", then paste as needed. Only documents available to the public have this feature enabled.