Grayling of Grebe Lake, Yellowstone National Park, Wyoming

Kruse, Thomas

This is a study of certain features of the grayling population in Grebe Lake (near the center of Yellowstone National Park) fundamental to its management as a recreational resource. Field work was done in the summers of 1952, 1953, and 1954. Grebe Lake is an eutrophic body of water at an elevation of 8,000 feet. It has an area of 145 acres and a maximum depth of 32 feet. The lake was covered with ice 6 1/2 months annually; the highest surface temperature recorded was 67°F. Predominant insects by volume and number were the Tendipedidae (=Chironomidae), larvae and pupae. By July 14, 1953, an oxygen deficiency in the waters below a depth of 20 feet made them unsuitable for fish life. The grayling was introduced in the lake in 1921. Rainbow trout were planted in 1907, and cutthroat trout in 1912 (only hybrid trout are present now). In the population estimates of 1953-54 trap nets were utilized along with a mark-and-recapture method. Approximately 28,000 grayling were in the lake in 1953 and 27,000 in 1954. The standing crop of fish in Grebe Lake each year approximated 81 pounds per acre of which 73 pounds per acre were grayling and 8 pounds per acre were trout....

Grayling of Grebe Lake, Yellowstone National Park, Wyoming

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