Thesis (Ph. D.)--University of Tennessee, Knoxville, 2004. / Title from title page screen (viewed May 14, 2004). Thesis advisors: Robert A. Bohm, Michael J. McKee. Document formatted into pages (xi, 185 p. : ill. (some color)). Vita. Includes bibliographical references (p. 116-122).

Thesis (M.A.)--University of Arizona. / Typewritten manuscript. Bibliography: leaves 61-70.

Declining unionid populations in the Clinch River are of concern due to the high endemism in the diverse fauna of the Cumberlandian region. Increase in agricultural and mining activities, as well as in industry and urbanization, are coupled with unionid declines throughout the watershed. In many reaches of the Clinch River, mussel populations exist which fail to show recruitment suggesting that this is the weak link in the complex life cycle. Two possible factors which could endanger the sensitive juvenile stage are the presence of sediment toxicants or adult Corbicula fluminea in the depositional areas, the preferred habitat of the juveniles. Before investigating the impacts of these factors, it was necessary to characterize the relationship of the juveniles with the sediment they inhabit. Observations of feeding behavior using videotape, dye studies in a feeding chamber, and gut content analysis were used to determine mechanisms of feeding, the primary food source, and the origin of substances taken up by juveniles. Exposure to sediment came not only through direct contact, but also through filtration of interstitial water and sediment-associated fine particulate organic matter. Juveniles used pedal locomotory and pedal sweep feeding behaviors to facilitate movement of particles into the pedal gape. Intermittent sediment toxicity was found in laboratory bioassays using Daphna magna and Chironomus riparius. These data, along with fluctuating metals in the Clinch River sediments, indicated that acute insults existed from which recovery would depend on the frequency, intensity and duration of the events. Field studies revealed that the intermittent toxicity is reflected in the community structure of benthic macroinvertebrates and impairs growth of juvenile unionids in-situ studies. The intermittent toxicity which may be associated with rain events impairs stream biota and may prevent recruitment of juvenile unionids. The presence of adult C. fluminea in sediments was found to decrease juvenile unionid growth and recovery from test sediments and to increase mortality and resuspension of juveniles into the water column. Both the presence of sediment-bound toxicants and C. fluminea may be contributing to unionid bivalve declines in the Clinch River, Virginia. / Ph. D.

Growth rates, age-frequency distributions, and mortality rates of six mussel species were examined at four sites in the Clinch River, Virginia and Tennessee, to identify potentially impacted sites in the upper river. The bioaccumulation of copper in mussel shells also was examined as a possible contributing factor to the declining mussel fauna. Higher growth rates observed at Hackneys site, river kilometer (RK) 433.7, may have been due to the discharge of domestic sewage from the town of Cleveland into the Clinch River. However, a sewage treatment facility was constructed in 1986 which removed the source of enrichment. Growth rates of female Lampsilis fasciola were significantly less than growth rates of male L. fasciola after 3 years of age, probably due to the onset of sexual maturity. Age-class distributions revealed an absence of recruited juveniles at the Slant site (RK 359.3) after 1977 to 1979 for four mussel species examined. Substantial erosion of stream banks in tributaries of the Clinch River and deposition of sediment in the Clinch River were observed at Slant, indicating a potential cause of decline. Mean annual mortality rates of adult mussels were extraordinarily high for all species at all sites, which confirms the overall decline of freshwater mussels in the upper Clinch River. There were no statistically significant differences in accumulation of copper in shells of L. fasciola among sites or sexes. Although Appalachian Power Company’s Clinch River Plant (CRP) had a history of high copper levels in the effluent discharge, it is apparently not the cause of reduced recruitment at the Slant site, located 72 km downstream. As indicated by this research, water quality or habitat conditions of the upper Clinch River continue to be insufficient to sustain freshwater mussels. The CRP has improved the effluent discharge to contain less than 12 μg Cu/L, which should improve conditions directly downstream; however, erosion of stream banks, sewage treatment facilities, and agricultural and urban runoff, continue to contribute to the demise of a rich freshwater mussel fauna. / Master of Science

The Clinch River, Virginia is known for high aquatic biodiversity, particularly Unionidae which are declining at remarkable rates. Studies conducted on the mainstem have only addressed effects of point-source stressors (various toxic spills and effluents from the Clinch River Plant (CRP), Carbo, Virginia) that have been introduced into the Clinch River. It is hypothesized that the tributaries of the Clinch River deliver a variety of stressors to the mainstem, which may affect the diverse fauna. The aquatic health of 19 upper Clinch River tributaries, Virginia, was assessed via ecotoxicological ratings that indicated the least healthy catchments were associated with mining activity (Dumps, Russell and Coal Creeks). Tributaries were categorized by land use and mining streams were significantly different from agricultural and forested streams (F = 9.63, p<0.0001). Tributaries with ecotoxicological ratings (ETR) <80 from 100 were deemed suboptimal and thus studied further. Using identical response variables and upstream and downstream sites, resulting ETRs for nine streams indicated no model significance regarding land use, year, or site. Variability within treatments and low sampling sizes contributed to lack of significance, and results indicate that future studies need to be designed incorporating sites with analogous land use stressors. This first assessment of upper Clinch River tributaries indicates the catchments requiring remediation are Dumps, Russell and Coal Creeks, while tributaries requiring extensive evaluations are Big, Lick, Swords, Big Spring, Guest River, Cavitts and Middle Creeks. Tributaries that were deemed healthy (ETRs >80) were Big Stony, Copper, Indian, Stock, Little River and Cove Creeks. / Master of Science

The periods of gravidity and glochidial release, required fish hosts, and age and growth characteristics of Fusconaia cuneolus were studied in the upper Clinch River, Virginia during 1986 and 1987. This summer brooder is gravid from mid-May through late July, releasing most glochidia in midJune. Gills of gravid females assume the color of enclosed conglutinates, and hues change from pink to peach as embryos mature to glochidia. As judged by diel sampling of stream drift, glochidia of the fine-rayed pigtoe are most abundant in the water column in early morning. A total of 1,619 fish representing 39 species were electroshocked and examined from the Clinch River at Slant for glochidial attachment. Prevalence of infestation of amblemine glochidia was highest on species of the Cyprinidae (27 to 46%), and six species were identified as possible fish hosts for the glochidia of the fine-rayed pigtoe. Amblemine glochidia were absent on non-cyprinid fish species. Glochidia exhibited host specificity in laboratory experiments, metamorphosing on the following seven minnow and one sculpin species: fathead minnow (Pimephales promelas), river chub (Nocomis micropogon), stoneroller (Campostoma anomalum), telescope shiner (Notropis telescopus), Tennessee shiner (Notropis leuciodus), white shiner (Notropis a/beo/us), whitetail shiner (Notropis galacturus), and mottled sculpin (Cottus bairdi). Tested species of sunfishes, catfishes, and darters did not serve as hosts. Age and growth characteristics were obtained by thin-sectioning shells collected in muskrat middens at Slant and Pendleton Island, Virginia. As predicted by the von Bertalanffy equation, the fine-rayed pigtoe achieves a maximum length of roughly 90 mm and age of 35 yr in the Clinch River. Annual growth in length averaged 5 mm/yr through age 10, decreasing to a rate of roughly 2 mm/yr thereafter. Based upon an age-length key, most individuals (50%) were of intermediate ages (13 to 16 yr). Specimens less than 10 yr old were uncommon, comprising only 22.4% of the deme at Slant. No individuals less than 6 yr old were found at Slant or Pendleton Island. Based on cohort structure at these sites, the fine-rayed pigtoe population appears to be declining in the Clinch River. A monitoring program is suggested. / Master of Science

This research was divided into four objectives for assessing the impacts of coal mining on ecosystem health. The first objective was to provide an ecotoxicological assessment in the upper Clinch River using standard bioassessment techniques. Analysis of sediments and interstitial water (porewater) indicate higher concentrations of trace metals in samples from sites located above both a power plant (CRP) and Dumps Creek mining influences. The furthest sampling site located near Pounding Mill, Virginia (CR-PM) had higher concentrations of aluminum (2,250.9 mg/kg), copper (5.9 mg/kg) and iron (12,322.6 mg/kg) compared to samples collected directly below the Dumps Creek confluence (site CR-2). Similar results were obtained from bioaccumulation in-situ tests with the Asian clam (Corbicula fluminea) in 2009. Aluminum (7.81 mg/kg), Fe (48.25 mg/kg) and Zn (7.69 mg/kg) were accumulated in higher concentrations at CR-PM site than CR-2. However, the site located below the CRP effluent discharges (CR-3L) on the left bank had substantially higher concentrations of Al (14.19 mg/kg), Cu (6.78 mg/kg), Fe (88.78 mg/kg) and Zn (7.75 mg/kg) than both CR-PM and samples collected directly opposite of this site at CR-3R. To further understand the potential impact active mining on the Clinch River, a more comprehensive ecotoxicological evaluation was conducting in the Dumps Creek subwatershed. Field bioassessments determined that biological impairment occurred directly below a deep mine discharge (CBP 001), which was characterized by a distinct hydrogen sulfide odor. Total abundance and richness of benthic macroinvertebrates decreased to 3.5-20 and 1.25-2.3, respectively at DC-1 Dn. The discharge also caused the proliferation of a sulfur-oxidizing bacterium, Thiothrix nivea. During continuous discharge of the effluent, the bacteria was observed coating all surfaces at DC-1 Dn and may also contribute to an Fe-encrusted biofilm observed on in-situ clams at downstream site, DC-2 Dn. Toxicity tests with mining effluents indicate some potential toxicity of the 001 discharge, but this was variable between test organisms. Selecting the most appropriate test species for sediment and water column assays has been a primary goal for ecotoxicologists. Standard test organisms and established test guidelines exist, but US EPA recommended species may not be the most sensitive organisms to anthropogenic inputs. Therefore, Chapter Three and Four addressed the use of mayflies in routine laboratory testing. Preliminary results of toxicity tests with the mayfly, Isonychia sp. (Ephemeroptera) suggested that Isonychia were moderately sensitive to NaCl after 96-hr with an average LC50 value of 3.10 g NaCl/L. When exposed to a coal-mine processed effluent, Isonychia generated LC50 values that ranged from 13 to 39% effluent and were more sensitive to the effluent than Ceriodaphnia dubia. Based on results of the feasibility study in presented in Chapter Four, field collected organisms appear to be too unpredictable in test responses and therefore, such tests would be unreliable as stand-alone indicators of effluent toxicity. / Ph. D.

The impact of a power plant discharge (Clinch River Plant, CRP, Carbo, Virginia) on resident snail populations was assessed. In 1988, snail absence below the plant, was attributed to plant discharges rather than naturally occurring habitat limitations. Habitat limitations for the two dominant snail species, Leptoxis praerosa and Pleurocera unciale were defined before power plant impact was assessed. Eleven physicochemical parameters (i.e., flow rate, substrate type, silt accumulation, depth, water chemistry and food biomass parameters) were measured at selected sites and compared to snail density. Flow rate, substrate type and periphyton biomass were the most influential parameters in determining Leptoxis density; while periphyton biomass was the most influential for Pleurocera. Cluster analysis also linked Leptoxis density with river structure and flow. Other variables linked to Pleurocera density were flow rate, river structure and silt. Although Leptoxis is most prolific in riffle/shoal areas and Pleurocera in slower riffle-pool interfaces, these two ‘species often coexist. This research suggests that habitat partitioning between these two species is influenced most by flow rate. Greatest density of Leptoxis occurred at flow rates of 20-30 cm/sec. Frequency of occurrence was greatest at 20-100 cm/sec. Pleurocera occurred most frequently at flow rates of 20-30 cm/sec with greatest density at 25-45 cm/sec. Measurements of impact of the CRP effluent (i.e., toxicity, metals {mainly copper} bioaccumulation in aufwuchs and snails, and cellulase enzyme activity impairment) were summarized by using zone delineation. Habitat parameters were measured below plant discharges and upstream, and compared with water column Cu, snail tissue Cu and aufwuchs Cu measurements. Habitat selection was strongly influenced by effluent but the role of waterborne metals concentration and habitat alterations (e.g. periphyton changes and bioconcentration) was unclear. Feeding studies were conducted to estimate impact of aufwuchs bioconcentration of metals on snails. Leptoxis significantly bioconcentrated Cu when fed aufwuchs containing 564 (±269) ug Cu/g in artificial stream feeding studies, but no cellulase impairments were seen in these studies. No foodborne bioconcentration was found from aufwuchs containing up to 20,000 (±18,400) ug Zn/L. These results suggest that though foodborne uptake of Cu may occur, water column Cu concentrations may have to be an order of magnitude higher for impairment to occur through injestion than through waterborne exposures. Acute and chronic effects of both whole effluent and Cu on Leptoxis were measured in laboratory and artificial stream exposures. The 96-hr LC₅₀ was 95% effluent (containing 148 ug Cu/L)in flow-through exposures, but in Static stirred exposures, 100% effluent (105 ug Cu/L)was not toxic. The lowest-observable effect concentration (LOEC)from 30-day exposures was 10% effluent (22 ug Cu/L) causing cellulase activity impairment (70% of control activity) and bioconcentration (300 ug Cu/g). Constituents of effluent other than Cu were believed to contribute to impairment effects since no impairment was found in 30-day CuSO₄ dosings of up to 25 ug Cu/L. The LOEC for Cu from 30-day CuSO₄ dosings ranged from 17-35 ug/L and the no-observed effect concentration (NOEC)was 12 ug Cu/L. The EPA water quality criteria concentration (17 ug Cu/L)was questionable for Leptoxis in long-term exposures (114-day), causing enzyme impairment and mortality. Chronically toxic conditions to Leptoxis occurred on the left side of the river for 0.7 km downstream of discharge, where the water column contained 42 ug Cu/L, while acutely toxic conditions occurred in the immediate mixing zone. Artificial stream impairment tests were substantiated in the river except in lower reaches of the impairment zone (left side of river, 0.7-0.9 km below cooling tower discharge), where snail absence was attributed to periphyton Cu bioconcentration (242 ug Cu/g). Functional recovery (of enzyme activity) was found at the next acceptable habitat downstream (Station 14A), so the area of impact extended 0.9 km downstream of the discharge on the left side of the river. It was concluded that zone delineation by simultaneously evaluating structural and functional aspects of environmental change is a better approach to impact assessment than approaches that only use functional measurements. / Ph. D.

No description available.

Freshwater mussel propagation techniques were tested at the Virginia Department of Game and Inland Fisheries Aquatic Wildlife Conservation Center through a series of three experiments. Experiment 1 tested the suitability of a pond and raceway for rearing juvenile oystermussels (Epioblasma capsaeformis) and wavyrayed lampmussel (Lampsilis fasciola). This experiment was prematurely terminated due to predation on mussels by fathead minnows (Pimephales promelas). Experiment 2 evaluated growth and survival of juvenile rainbow mussels in outdoor troughs and indoor aquaria. There was no significant difference in survival or growth between the two systems. Experiment 3 used troughs similar to those in Experiment 2 to rear E. capsaeformis and L. fasciola under two silt regimes. Survival for Experiment 3 was significantly greater for L. fasciola. The comparison between silt regimes indicated that individuals in the high-silt treatment had better survival than those in the low-silt treatment. The difference between these 2 treatments may be a reflection of increased escapement in the low-silt treatment, which may have resulted from more frequent disturbance during sampling. Growth of L. fasciola was significantly greater than E. capsaeformis, and was greater in the low-silt treatment. A habitat survey of the Clinch River, Virginia was conducted from Blackford, Clinch River Kilometer (CRK) 478 to the Tennessee border, CRK 325. Physical characteristics identified in the survey were combined with water quality and impact source data to develop a habitat suitability index for freshwater mussels within this study reach. Model parameters were indexed and weighted to give a final suitability ranking. Habitat units having the highest overall ranking included: Nash Ford (CRK 449), Artrip (CRK 442), several riffles and runs below Carterton (CRK 417), upstream of Mill Island (CRK 389.5), and Pendleton Island (CRK 365), and Speers Ferry (CRK 333-325). Potential locations for habitat restoration projects and additional monitoring were also identified. / Master of Science