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Leo F. Erkkila

Publications and source records attributed to Leo F. Erkkila.

5 recordsLinked to original sources
USGS1965

Food of lake trout in Lake Superior

Stomachs were examined from 1,492 lake trout and 83 siscowets collected from Lake Superior. Data are given on the food of lake trout of legal size (17 inches or longer) by year, season, and depth of water, and on the relation between food and size among smaller lake trout. Fish contributed 96.7 to 99.9 per cent of the total volume of food in the annual samples. Ciscoes (Coregonus spp.) were most common (52.2 to 87.5 per cent of the volume) in 1950 to 1953 and American smelt ranked first (65.6 per cent of the volume) in 1963. Cottids were in 8.9 to 12.3 per cent of the stomachs in 1950 to 1953 but in only 4.3 per cent in 1963. Insects ranked second to fish in occurrence (9.6 per cent for the combined samples) and crustaceans followed at 3.9 per cent. The greatest seasonal changes in the food of lake trout were among fish caught at 35 fathoms and shallower. The occurrence of Coregonus increased from 34.6 per cent in February-March to 71.1 per cent in October-December. Smelt were in 76.9 per cent of the stomachs in February-March but in only 2.2 per cent in October-December. Cottids, Mysis relicta, and insects were most common in the July-September collections. Lake trout taken at depths greater than 35 fathoms had eaten a higher percentage of Cottidae and Coregonus than had those captured in shallower water. Smelt, ninespine sticklebacks, Mysis, and insects were more frequent in stomachs of lake trout from less than 35 fathoms. Crustaceans comprised more than 70 per cent of the total volume of food for 4.0- to 7.9-inch lake trout but their importance decreased as the lake trout grew larger. Pontoporeia affinis was the most common in the stomachs of 4.0- to 6.9-inch lake trout and Mysis held first rank at 7.0 to 12.9 inches. Ostracods were important only to 4.0- to 4.9-inch lake trout. As the lake trout became larger, the importance of fish grew from 4.4-per cent occurrence at 5.0 to 5.9 inches to 93.9 per cent at 16.0 to 16.9 inches. Smelt were most commonly eaten by undersize (less than 17 inches) lake trout.

Transactions of the American Fisheries Society↗
USGS1953

The movement of tagged lake trout in Lake Superior, 1950-52

A total of 733 native lake trout was tagged at two widely separated localities in Lake Superior; subsequent recaptures numbered 155 fish (21.1 percent) during the year following marking. In October 1950, 116 large lake trout (average total length, 27.3 inches) were tagged near Keweenaw Point, Michigan. Fifteen (12.9 percent) were recovered during the first year at points as far west as the Gooseberry River, Minnesota (190 miles), north to the Slate Islands, Ontario (95 miles), and east to Grand Marais, Michigan (100 miles). Nine fish (7.8 percent) were recovered during the second year after marking. Returns from 617 tagged lake trout of smaller size (average length 18.2 inches) released in the Apostle Island region of Wisconsin during the period June 12 to August 6, 1951, numbered 140 (22.7 percent) during the first year. Of these fish, 90 percent were recaptured within a radius of 50 miles of the points of release. Seventy-six percent were caught in Wisconsin, 14 percent in Minnesota, and 9 percent in Michigan waters. The fish retaken in Michigan had moved 120 to 255 miles between the time of release and recapture, traveling as far west as Grand Marais. Lake trout recaptured at distances of more than 50 miles from the tagging locality were of larger average size than marked fish caught within this radius. The four types of tags used in the marking of lake trout in the Apostle Island region, together with the number tagged and percentage recovered during the first year were as follows: 103 aluminum lower-jaw tags (used only on fish less than 17 inches in length when marked)-10.7 percent; 200 monel upper-jaw tags-14 percent; 162 streamer tags-19.8 percent; and 152 Peterson tags-45.4 percent. Obviously lake trout marked with the Peterson tag, with the discs and ends of the pin projecting from each side near the point of maximum girth, were more vulnerable to the fishery than were fish marked with other tags. The recoveries of marked fish show that Lake Superior lake trout-particularly fish of large size-may move many miles and freely cross political boundaries; and that the rate of harvest is moderately high for a fish with a life history as long as that of the lake trout.

Michigan, Minnesota, Wisconsin↗
USGS1953

Movement of tagged lake trout in Lake Superior, 1950-1952

A total of 733 native lake trout was tagged at two widely separated localities in Lake Superior; subsequent recaptures numbered 155 fish (21.1 percent) during the year following marking. In October 1950, 116 large lake trout (average total length, 27.3 inches) were tagged near Keweenaw Point, Michigan. Fifteen (12.9 percent) were recovered during the first year at points as far west as the Gooseberry River, Minnesota (190 miles), north to the Slate Islands, Ontario (95 miles), and east to Grand Marais, Michigan (100 miles). Nine fish (7.8 percent) were recovered during the second year after marking. Returns from 617 tagged lake trout of smaller size released in the Apostle Island region of Wisconsin during the period June 12 to August 6, 1951, numbered 140 (22.7 percent) during the first year. Of these fish, 90 percent were recaptured within a radius of 50 miles of the point of release. Seventy-six percent were caught in Wisconsin, 14 percent in Minnesota, and 9 percent in Michigan waters. The fish retaken in Michigan had moved 120 to 255 miles between the time of release and recapture, traveling as far east as Grand Marais. Lake trout recaptured at distances of more than 50 miles from the tagging locality were of larger average size than marked fish caught within this radius.

The Fisherman↗