Hatching success of lake trout eggs in artificial incubation substrates in Harding and Seven Mile Lakes
By: by Tim Viavant.
Contributors: Alaska. Division of Sport Fish.
Series: Fishery data series -- no. 98-30.
Publisher: Alaska Dept. of Fish and Game, Division of Sport Fish, Research and Technical Services
Published: 1998
Place of publication: Anchorage
Language: eng
Number of pages: 11
Subjects: Lake trout -- Alaska -- Harding Lake -- Statistics.; Lake trout -- Reproduction -- Testing.; Fish-culture -- Alaska -- Harding Lake -- Statistics.; Lake trout -- Alaska -- Seven Mile Lake -- Statistics.; Fish-culture -- Alaska -- Seven Mile Lake -- Statistics.; Seven Mile Lake (Alaska).; Harding Lake (Alaska).
Description: Lake trout Salvelinus namaycush eggs and milt were taken from fish captured in September, 1997, from Seven Mile Lake. After being fertilized, eggs were allowed to water-harden for 1.5 h, and then placed into artificial incubation substrates which were placed at two different water depths in Seven Mile and Harding lakes. A fixed volume of eggs equaling approximately 225 eggs was hand counted into each of two layers of 12 artificial incubation substrates at each lake. Six substrates were placed on known lake trout spawning areas (at Seven Mile Lake) or onto introduced spawning substrates (at Harding Lake) at both 1.5 m and 3.0 m deep (12 total in each lake). Eggs and substrates were blocked by order of handling, one block consisting of one substrate placed at each depth. Twelve substrates in six blocks were placed in Seven Mile Lake immediately after the eggs water-hardened, and the same process was carried out 6 h later after the remaining eggs were transported to Harding Lake. Soon after ice melt in the spring of 1998 (May 21 at Harding Lake, June 20 at Seven Mile Lake), substrates were recovered and the unhatched eggs and dead fish were counted and the number recorded. The average percentage of eggs hatching was 66.2% at Seven Mile Lake and 49.7% at Harding Lake. There were no significant differences in the percentage hatching at either lake due to the depth of the substrates or among blocks.
Notes: "November 1998"

Includes bibliographical references (p. 7-8).

Also issued online.