In the second year of the coarse fish broodstock project, a comprehensive evaluation of Blackwater River rainbow trout stocks was initiated. Seven lakes containing coarse fish were stocked with Blackwater River and Pennask Lake (control) stocks in equal numbers in May, 1989. Growth, relative survival and maturity of these two stocks were compared at the end of one growing season. Blackwater River stock grew up to 6% larger than the Pennask strain in 6 lakes, but relative survival ranged from 1.2:1 Pennask to Blackwater in Gladstone Lake, to 9.8:1 in Pear Lake, at age 1+. Age 2+ Blackwater stock from the 1988 stocking in Garcia and Mathew lakes were 2.7 times larger, by average weight, than the Pennask strain fish. Relative survival of the age 2+ fish, however, was 4:1 and 3.5:1 Pennask Lake to Blackwater River stock, in Mathew and Garcia lakes. Coarse fish were found in gut samples of 1% of the total age 1+ Blackwater stocks, and 21% of age 2+ Blackwater fish. No fish were found in stomachs of Pennask Lake stock of either age class. Early sexual maturity appeared to be lake specific, not strain dependent, in this study.
Brood fish were collected from Bootjack, Tzenzaicut, and Tsuniah lakes. Progeny from these broodfish and Blackwater River stock will be liberated as 1+ fish along with the Pennask stock, for further comparisons, in the spring of 1990.
Blann, Vicki E., Tsumura, Kanji. 1989. Rainbow Trout Broodstocks for Coarse Fish Lakes: Habitat Conservation Fund Progress Report (1989-90). Ministry of Environment. Fisheries Project Report. RD22