Density estimates of the species and life stages in different habitat types were made from electrofishing collections and underwater fish counts. During midday, fish densities in edge pool and riffle habitats were comparable, but densities in edge pool habitat were significantly higher than densities in middle pool and run habitats. Snag and edge riffie habitats supported the highest densities of fish. Habitat use and activity shifts between daytime and nighttime were found for many species. Fish species and lifestage composition and densities differed among the habitat types, and five habitat-use guilds (edge-pool, middle-pool, edge-channel, riffie, and generalists) were described. Larger centrarchids preferred deep habitats with slow velocities (deep edge and middle pool, and snags), while young centrarchids preferred shallower habitat. However, all sizes of smallmouth bass were nearly ubiquitous in the habitats of the study area. The cyprinids and percis preferred shallow areas, but preferences for velocity differed among the species and lifestages. Spawning and habitat preferences of the endemic bigmouth chub, Nocomis platyrhynchus, were described. Bigmouth chubs used areas with plenty of small to large gravel (3-64 mm diameter), shallow depths, and moderate velocities for constructing spawning mounds. Bigmouth chubs were seen only using riffie and adjacent run habitat during late summer. Within these areas, depth, velocity, substrate, and cover were used in accordance with their availability, except for an avoidance of the shallowest available depths. Bigmouth chubs occupied positions near the substrate, where velocities were slower than the mean water column velocity. / M.S.

Thesis (M.L.A.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 99-101). Also available via the Internet.

Reservoir releases for power generation often cause rapidly fluctuating water levels and increased velocities in certain downstream sections of rivers. These conditions and the natural geometry of the river can render certain sections of the river dangerous for recreation. Although public utilities take precautionary safety measures immediately downstream of the dam, their measures further downstream have been limited, if not non-existent. The placement of weirs between the dam and dangerous sections would retard the flow—slowing the rise in water levels and decreasing velocities at predetermined dangerous sections. Big Falls, on the New River near McCoy, Virginia, is a popular recreation spot and becomes dangerous at certain times of the day due to releases from Claytor Lake Dam. Several people have drowned at this location over the years. In this study, the influence of weirs placed upstream of Big Falls on the rise of water level and increase in velocity is investigated by an implicit finite difference computer model of one-dimensional gradually varied unsteady flow. The model allows for investigation of different weir geometries and placements, and the effectiveness of these weirs when subjected to various boundary conditions which arise from variations of the maximum peak release hydrograph from Claytor Lake Dam from May to September of 1983 and 1984. Results of the study consist of the optimum weir geometry and placement on the New River upstream of Big Falls. Criteria for determining the weir included physical location limitations, and the effectiveness of the weir in reducing the rate-of-rise of water levels and increased velocities at Big Falls. / M.S.

A model of the trophic dynamics among key macroinvertebrate and fish populations in the New River, West Virginia, was developed to help define the roles of predation, competition, and fishery exploitation in the food web of this large, warmwater stream. The fates of production of the harvested crayfish (Orconectes virilis, Orconectes sanbornii sanbornii, and Cambarus sciotensis), hellgrammite (Corydalus cornutus larvae), smallmouth bass (Micropterus dolomieui), rock bass (Ambloplites rupestris), and flathead catfish (Pylodictis olivaris) populations were quantified to evaluate the status of these stocks and to aid specification of the model. Analysis and application of the model were designed to address three research objectives, which were to (1) quantify the roles that predation, competition, and exploitation have in structuring the prey-predator assemblage, (2) evaluate through simulation the effects of multispecies exploitation, and (3) assess through simulation the impacts to the food web of reductions in aquatic insect production associated with the systematic control of black fly larvae in the New River. The trophic basis of production of smallmouth bass, rock bass, and flathead catfish was primarily aquatic insects (in young fishes) and crayfish (in older fishes). Hellgrammites and prey fishes were inconsequential in that regard. Predation by these fishes (primarily smallmouth bass and rock bass) accounted for 76% of the production of ages-1 and -2 crayfish, and harvest by people was equivalent to 5% of crayfish production. Fish predation (primarily by rock bass) and harvest accounted for 14% and 8%, respectively, of the annual production of ages-1 and -2 hellgrammites. Anglers harvested the equivalents of about 91% and 12% of the annual production of fully-recruited smallmouth bass and rock bass, respectively; the extent of flathead catfish harvest was unclear. Error analysis of the model suggested that “bottom-up" (food-limitation) effects were more important than “top-down" (mortality from predation) effects, interspecific and intraspecific competition, and exploitation in maintaining the structure of the prey-predator assemblage in the New River. Exploitation was important in causing transitions in assemblage structure. Simulations of multispecies exploitation demonstrated that production and yield of populations are strongly dependent on food web interactions. Simulation of a 50% reduction in aquatic insect production, similar to that observed following poisoning of black fly Iarvae, predicted substantial declines in insectivores and their predators. Management of New River resources for maxi- mum benefits to people will necessarily involve new approaches to addressing problems in a food web context. / Ph. D.

The effectiveness of a guide training program was evaluated as a means of providing interpretive services to commercial boaters at the New River Gorge National River. Commercial river guides attended a National Park Service sponsored training program which provided accurate information and education concerning natural and cultural history of the New River, the national significance of the New River Gorge National River, the history and purpose of the National Park Service, and information and services available at the visitor centers. The emphasis of the training session was to increase the river guides’ knowledge base and to encourage their interpretive presentation of this information to their customers. Customers of a commercial outfitter were administered a questionnaire before and after the guide training program. Significant differences in the amount of interpretation guides presented on the river, the amount of knowledge customers acquired during the trip, and the customers' overall trip rating were noted by empirical testing. Increases in the means of all three outcome variables occurred following guide training. Customers’ intentions to visit a New River Gorge Visitor Center did not significantly change following guide training. The validity and reliability of the instrument is discussed as well as potential biases and constraints of the study. Implications for management and further research are also discussed. / M.S.