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Hydrology and trout populations of cold-water rivers of Michigan and Wisconsin, 1974

By: Hendrickson, G.E., and Knutilla, R.L.


In the cold waters of Michigan and Wisconsin, statistical multiple-regression analyses show significant relationships between trout populations and hydrologic parameters. Parameters showing the higher levels of significance are temperature, hardness of water, percentage of gravel bottom, percentage of bottom vegetation, variability of streamflow, and discharge per unit drainage area. Trout populations increase with lower levels of annual maximum water temperatures, with increase in water hardness, and with increase in percentage of gravel and bottom vegetation. Trout populations also increase in discharge per unit drainage area. Most hydrologic parameters were significant when evaluated collectively, but no parameter, by itself, showed a high degree of correlation with trout populations in regression analyses that included all the streams sampled. Regression analyses of stream segments that were restricted to certain limits of hardness, temperature, or percentage of gravel bottom showed improvements in correlation. Analyses of trout populations, in pounds per acre and pounds per mile and hydrologic parameters resulted in regression equations from which trout populations could be estimated with standard errors of 89% and 84%, respectively. (KNAPP-USGS)

RECORD ID: 7502819

F&G CODE: 02e; 08i

Hendrickson, G.E., and Knutilla, R.L., 1974, Hydrology and trout populations of cold-water rivers of Michigan and Wisconsin: Wisconsin Academy Sciences, Arts, and Letters, v. LXII, p. 181-193.

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