Lake trout (Salvelinus namaycush), chinook salmon (Oncorhynchus tschawytscha), coho salmon (Oncorhynchus kisutch), steelhead trout (Salmo gairdneri), and brown trout (Salmo trutta were collected from April 30 to November 18, 1970 with gill nets at selected sites in Lake Michigan near Gary, Burns Ditch, and Michigan City, Indiana. Catch-per-uniteffort was law and most catches occurred when nets were set in water temperatures in the 50 F (10.0 C) range or lower. Sea lamprey (Petrcnyzon marinas) scars and wounds were found on 25.4% of 71 lake trout captured and fresh wounds occurred on 6.0% of the fish. Scars and wounds were restricted to lake trout 20.0 in. (50.6 cm) or greater in total length and 32.7% of the 55 fish in this size group carried scars or wounds.Food items in stomachs of 39 lake trout, 34 coho salmon, and 29 chinook salmon were expressed as percent frequency of occurrence, numerical percent, and volumetric percent. The alewife (Alosa pseudoharenp_us) was the predominate food consumed by all three species. The crustaceans, Mysis sp. and Pontoporeia affinis, were consumed only by lake trout less than 19.0 in. (48.1 cm) total length.The age and growth of 69 known age fin clipped lake trout were examined. The body-scale relationship was TL = 6.2001 + 0.1238 Sc. The mean calculated total lengths for the first 5 years of growth were 5.3, 10.7, 16.3, 21.0, and 24.0 in. (13.5, 27.2, 41.4, 53.2, and 60.8 cm). Annual growth is considerably greater than recorded for Lake Michigan lake trout prior to alewife introduction and dominance. The length-weight relationship was log W = -2.5087 + 3.2338 log L which agrees closely with previous length-weight analyses of Lake Michigan lake trout.Ball State UniversityMuncie, IN 47306
| Identifer | oai:union.ndltd.org:BSU/oai:cardinalscholar.bsu.edu:handle/180706 |
| Date | 03 June 2011 |
| Creators | Miller, William G. |
| Contributors | McComish, Thomas S. |
| Source Sets | Ball State University |
| Detected Language | English |
| Format | vi, 39 leaves : ill. ; 28 cm. |
| Source | Virtual Press |
| Coverage | nl----- |
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