An Evaluation of Relationships Between the Fish Community and Environmental Characteristics of the White River, Arkansas

The White River is 1,162 km long and flows through Southern Missouri and much of Northern and Eastern Arkansas. There are three major reservoirs that alter natural flow and release hypolimnetic water providing conditions for trout fisheries. In the summer of 2010 we collected fish using a boat mounted electrofisher sampling at 15 km intervals beginning near the confluence with the Mississippi River and ending at river km 660 below Bull Shoals Dam. A total of 83 species were collected.  At each sample site 12 water quality and physical habitat characteristics were collected. Canonical correspondence analysis was used to assess relationships between fish species relative abundance and environmental variables.  The model explained 39.9% of the total variation; axis 1, 2, and 3 accounted for 19.9, 10.4, and 9.6% of the variation in community structure, respectively. Correlations between environmental variables and canonical axis 1 depicted a gradient involving temperature, rock substrate, depth, and turbidity. Species-axis correlations indicated that species with the strongest association with cooler water, more rock, shallower depth, and less turbidity included brown trout Salmo trutta, rainbow trout Oncorhynchus mykiss, cutthroat trout Oncorhynchus clarkia, white sucker Catostomus commersonii, and banded sculpin Cottus carolinae. This association corresponds to an area from the tailwater down river approximately 160 km. Species associated with warmer water, less rock, increased depth, and more turbidity included  spotted bass Micropterus punctulatus, longear sunfish Lepomis megalotis, bigeye shiner Notropis boops, brook silverside Labidesthes sicculus, and longnose gar Lepisosteus osseus. This association describes the lower 400 km of the river. Axis 2 contrasted locations based on macrophytes, conductivity, velocity, and overhanging vegetation. Species associated with macrophyte presence, greater conductivity, higher velocity, and greater overhanging cover included walleye Stizostedion vitreum, yellow perch Perca flavescens, inland silverside Menidia beryllina, brown trout, and rainbow trout. Species associated with lower macrophyte presence, lower conductivity, slower velocity, and less overhanging cover included golden redhorse Moxostoma erythrurum, northern hogsucker Hypentelium nigricans, striped shiner Luxilus chrysocephalus, smallmouth bass Micropterus dolomieu, and largemouth bass Micropterus salmoides. Correlations for axis 3 depicted a gradient involving conductivity, overhanging vegetation, velocity, width, and turbidity. Species associated with greater conductivity, greater cover, faster velocity, greater width, and less turbidity inlcuded inland silverside, pumpkinseed Lepomis gibbosus, blackstripe topminnow Fundulus notatus, and golden redhorse. Species associated with less conductivity, less cover, slower velocity, smaller width, and more turbidity included bigeye shiner, blacktail shiner Cyprinella venusta, spotted bass, walleye, and yellow perch.