WSP09970 - Laserfiche WebLink

Home Browse Search

, , '00311'8 respectively. The fry survival rates at age 1+, 2+, and 3+ for the SB section are very similar to those reported by Hume and Parkinson (l988) for steelhead fry ranging in size from 0.2-6 g. Hume, and Parkinson (l987) reported that stocking densities of steelhead fry between 0.3 and 0.7 f~y/m2 maximized the production of steelhead parr and smolts.They also,' reported that downstream dispersal of point-stocked fry was very poor, similar to the findings in other studies (Mortensen 1977jEgglishawand . Shackley 1980). We have found this to be the case in our studies as well. Table lO. State Bridge trout population estimates, Rio Grande River, 1981-87. Browns Rainbows Year, N kg/l).a N/ha ,35 cm N kg/ha . N/ha 35 cm 1981 5,l(i8 39,3 29 295 2.8 4 1982 6,753 38.9 35 l43 0.8 1 1983 8,948 45.4 31 285 1.9 2 1984 6,597 32.9 15 325 1.7 2 1985 6,372 30.9 28 896 3.5 3 1986 6,373 32.0 24 2,077 5.2 2 ,1987 7,483 35.8 35 l,791 4.1 3 '" Table 11. State Bridge total rainbow trout per section, Rio Grande River. Sample period Year class Month Year 1986 1985 1984 1983 ' 1982 1981 1980 ' 1979 1978 1977 1976 1975 Aug. 1982 212 75 94 137 3l 0 0 Sept. 1983 62 l08 2l 39, 55 0 0 0 Sept. 1984 l40 67 95 5 23 0 0 Sept. 1985 466 233 87 79 29 0 , Sept. 1986 l,652 407 163 64 7 Sept. 1987 544 740 153 80 34 1 All three study sections on the Rio Grande received the largest stocking of CRR and TAS strain rainbows in 1987 since, the study began (Table 7). It was also the first planting of CRR strain rainbows that exceeded lO cm (4 in.) in size. I am hopeful that we ,will see a large increase in rainbow density at all three study areas with the increase in both numbers and average size of fingerlings stocked. .i;, n _~':" '::.: i". " ' ", i ~. ._ ~;~ ~ .' 11 00002405