Fisheries Investigations – 02 Methods

Fisheries Investigations in Crater Lake, Oregon, 1937-1940 by Arthur D. Hasler and D. S. Farner



A creel census conducted each summer through the cooperation of Paul Herrin, E. Wilcox, the ranger staff, and CCC workers recorded about 90 per cent of the catch by all anglers. This favorable return resulted from the fact that only one trail to the lake was in passable condition and the only boat concession on the lake was at the base of this trail. Some natives of the region may have reached the lake by devious passes and fished from rafts or from shore, but shore fishing has proved to be unfruitful, and fishing by this group is assumed to be less than 10 percent of all angling.

A group of fishes was selected at random from the angler’s creel each day for study of growth and survival of year classes, and to obtain general fishery information. Each fish was weighed and measured, its sex determined, and a few scales removed from below the dorsal fin. The data were analyzed according to procedures introduced by Hile (1941). The observations recorded here on the growth of salmonids serve only to interpret fishery problems and not as a contribution to the techniques of scale analyses.

1 Aided by the National Park Service, CCC, NYA, and the Department of Zoology, University of Wisconsin.

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