Mannheim Fishway Project

Bunt, C.M. 1999. Denil fishway utilization patterns and passage of several warmwater species relative to seasonal, thermal and hydraulic dynamics. In: Fishways for warmwater fishes:  utilization patterns, attraction efficiency, passage efficiency and relative physical output. Ph.D. thesis. University of Waterloo.

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Bunt, C.M., B.T. van Poorten and L. Wong. 2001. Denil fishway utilization patterns and passage of several warmwater species relative to seasonal, thermal and hydraulic dynamics. Ecology of Freshwater Fish. 10: 212-219.

Abstract.-Fishways that allow passage of as many constituents of local ichthyofauna as possible are necessary if the concept of sustainable development is to be realized. In the present study, two Denil fishways on the Grand River, Ontario, were used as check-points to evaluate the transfer of fishes over a low-head weir and to examine the proportions and inferred swimming performance of 29 warmwater fish species that used each fishway type. These species included black crappie, bluegill, bluntnose minnow, brown bullhead, common carp, common/striped shiner, common/emerald shiner, common shiner, creek chub, emerald shiner,  golden shiner, greenside darter, green sunfish, hornyhead chub, Iowa darter, largemouth bass, longnose dace, golden redhorse, greater redhorse, northern hog sucker, pumpkinseed, rainbow darter, river chub, rock bass, rosyface shiner, smallmouth bass, stonecat, striped shiner and white sucker.  Traps installed at fishway exits were used to collect fish over 24 hour sampling periods, during 40 – 51 days each year from 1995 to 1997. Passage rates, mean temperature, water velocity and turbidity for the date of maximum passage for each year were analyzed. General species composition from trap samples shifted from catostomids to cyprinids to ictalurids to percids and centrarchids, with some overlap, as water temperatures increased from 8 – 25 ° C. Due to variable accumulations of debris on upstream trash racks, water depths and therefore water velocities in each fishway were independent of river discharge. Correlations between water velocity and swimming/position-holding abilities by several species emerged. Turbidity was directly related to river discharge and precipitation events, and many species demonstrated maximum fishway use during periods of decreased water clarity. This study 1) provided evidence of migratory tendencies among several species which were previously considered non-migratory and 2) may assist fishery managers in matching physical and biological conditions within fishways with expected patterns of use by a large array of "coarse" fish, bait fish and sport fish.