Factors Influencing Hoop Net Catches in Channel Habitats of Pool 9, Upper Mississippi River

The catch per unit of effort and species selectivity of two hoop net types fished in channel habitats of Pool 9 were described. Variation in catch was noted between the two net types, as well as between sampling areas and channel types. The total catch with bait nets was 580 fish in the main channel border and 539 in side channels, while buffalo nets captured 1,213 fish from the main channel border and 1,004 from side channels with the same amount of fishing effort. Six species comprised 93% of the bait net samples: shorthead redhorse, black crappie, freshwater drum, flathead catfish, bluegill, and channel catfish. The six most abundant species in buffalo nets were: shorthead redhorse, freshwater drum, smallmouth buffalo, mooneye, bluegill, and common carp. Species collected in greater numbers in main channel border habitats were: gizzard shad, mooneye, quillback, white sucker, smallmouth buffalo, bigmouth buffalo, channel catfish, flathead catfish, and black crappie. Side channels produced greater numbers of common carp, shorthead redhorse, and bluegill. Multiple regression analysis showed that variation in water temperature, current velocity, turbidity, dissolved oxygen, channel type, and sampling area accounted for variation in the catch of several fish species. Turbidity was the most common variable to be related to catch and tended to have a negative relationship