Comparative performance of stocked mixed-sex and all-female rainbow trout and diploid and triploid coho salmon in landlocked lakes in southcentral Alaska, 1994 and 1995
By: by David S. Rutz and Craig C. Baer.
Contributors: Baer, Craig.; Alaska. Division of Sport Fish.
Series: Fishery data series -- no. 96-23.
Publisher: Alaska Dept. of Fish and Game, Division of Sport Fish, Research and Technical Services
Published: 1996
Place of publication: Anchorage
Language: eng
Number of pages: 25
Subjects: Fish stocking -- Alaska -- Southcentral Region.; Coho salmon -- Alaska -- Southcentral Region.; Rainbow trout -- Alaska -- Southcentral Region.
Description: Survival and growth of mixed-sex rainbow trout were compared to all-female rainbow trout by stocking the two treatment groups at equal densities in Long (Kepler-Bradley lakes complex), Johnson, and "X" lakes in Southcentral Alaska in July 1993. Rainbow trout were age 0+ and average weight was 1.1 g at stocking. Proportions and mean lengths at age 1+ and age 2+ were estimated for each group in May 1994, September 1994, and September 1995. Survival, from stocking in July 1993 to September 1994, of the two groups was also compared. Proportion of all-female rainbow trout remained near 50% for Long and Johnson lakes, but varied from 37% to 48% for X Lake. In May 1994 and September 1994, mixed-sex rainbow trout were significantly larger than all-female rainbow trout, but by less than 5 mm. In September 1995, mixed-sex rainbow trout were significantly larger in Johnson and Long lakes, but were significantly smaller in X Lake; the length differences for all lakes were less than 20 mm. Survival of rainbow trout from stocking in July 1993 to September 1994 was about 9% for Long Lake, about 11% for Johnson Lake, and about 2% for X Lake. In September 1994, abundance of mixed-sex and all-female rainbow trout was not significantly different for all three lakes. Diploid and triploid coho salmon were stocked at equal densities in Johnson Lake during May 1994. Diploid coho salmon averaging 6.8 g and triploid coho salmon averaging 6.0 g at stocking were used for this experiment. Proportions and mean lengths of the two groups were compared in September 1994 and September 1995. Diploid coho salmon were significantly larger than triploid coho salmon in both years. In September 1994, 56% of the stocked coho salmon were diploid, 44% were triploid; in September 1995, 75% were diploid and 25% were triploid.
Notes: "August 1996."

Includes bibliographical references (p. 18-19).

Also issued online.