The overall objective of this study was to identify trends of sediment nutrients and benthic macro-invertebrates in recreational fishing ponds. The Ekman dredge and the Yabby pump, also were compared for benthic macro-invertebrate sampling effectiveness. Large ranges in the coefficient of variation for Pw (52 – 123.9), C:N (13.4 – 124), density (61.5 – 98.5), and diversity (67 – 142) indicated significant spatial variability within and among ponds. Invertebrate familial diversity was the only variable that did not show any significant temporal variation (H = 4.31, P = 0.230). Results from the gear comparison indicated no differences between the Ekman dredge and Yabby pump (3 pulls); however, showed the Ekman dredge was more effective than the Yabby pump (12 pulls) (Z = -1.796, P = 0.073) indicating potential gear saturation. Although these data supported no discernable patterns between sediment nutrients and macro-invertebrates, it provided an opportunity to detail an operational framework for future studies.

Rivers are among the most anthropogenically affected ecosystems in the world by irrigation, transportation, channelizing, and hydropower. Habitat restorations have become a popular method to restore the heterogeneity and complexity of rivers aiming for improvement of biodiversity. In this master thesis, I studied the effects of restoration in a regulated and channelized river in the middle of Sweden. Differences in fish abundance and diversity together with hatching success and survival rate from egg to smolt of Seatrout (Salmo trutta) and Atlantic salmon (Salmo salar) were tested between restored and unrestored reaches. In addition, differences in abundance, biomass, diversity, and composition of benthic species between restored and unrestored areas were studied.  The study design consisted of three restored and three unrestored locations where artificial spawning grounds (redds) were placed, electrofishing was conducted, and an inventory of abundance, biomass and diversity metrics of benthic fauna was performed. Whitlock-Vibert boxes were used in the artificial redds and were used to calculate hatching success. The inventory of benthic fauna consisted of kick-sampling and sampling of stones followed by identification and measuring of length in the lab.  The findings in this study suggest that the survival of salmonids is not limited by the hatching success but that the lack of migration possibilities and the low survival rate from egg to smolt makes it unlikely with a successful reintroduction of Atlantic salmon and seatrout in Dalälven. Furthermore, one could argue that the habitat restorations have not increased the diversity of benthic fauna. However, it is possible that there is an ongoing shift in the benthic fauna towards a more diverse community in the restored areas and it is possible it will be more visible in a few years which supports maintaining long-term monitoring. Lastly, this study enlightens consequences with anthropogenically affected rivers and leaves opportunities for further studies.

No description available.

学位プログラム名: 京都大学大学院思修館 / 京都大学 / 0048 / 新制・課程博士 / 博士(総合学術) / 甲第22610号 / 総総博第10号 / 新制||総総||2(附属図書館) / 京都大学大学院総合生存学館総合生存学専攻 / (主査)教授 山敷 庸亮, 准教授 趙 亮, 准教授 竹門 康弘 / 学位規則第4条第1項該当 / Doctor of Philosophy / Kyoto University / DFAM

Relationships between macroinvertebrate assemblages and environmental stressors were assessed from fall 2002 through spring 2004 in five small streams that represented a study design that involved a gradient of increasing stress (increased cattle density). Macroinvertebrate assemblages were related to environmental factors that were quantified at the sample scale. Environmental factors and macroinvertebrates were concurrently collected so that assemblage structure could be directly related to environmental variables and so that the relative importance of stressors associated with cattle grazing in structuring assemblages could be assessed. Macroinvertebrate metrics showed significant and strong responses to cattle density during most sampling periods. The majority of metrics responded negatively to the grazing gradient, while a few (total taxa richness, number of sensitive taxa, and % collector filterers) increased along the gradient before declining at the most heavily grazed sites. Total number of sensitive taxa and % Coleoptera had the strongest relationship with cattle density throughout the study period. Based on sample-scale, quantitative measures of environmental variables, measures of physical habitat (% fines and substrate homogeneity) were most important in structuring assemblages. Detrital food variables (coarse benthic and fine benthic organic matter) were secondarily important while autochthonous food variables (chlorophyll a and epilithic biomass) were not as important in influencing assemblage structure. Based on a comparative analysis of reach-scale habitat measures and estimates, quantitative measures of % fines, collected from within an enclosed sampler concurrently with macroinvertebrates, were the best predictor of macroinvertebrate assemblages. Quantitative measures and visual estimates of riparian and channel characteristics had strong relationships with macroinvertebrate metrics but the relationships were never as strong as those detected with instream measurements of % fines. The channel characteristic, bank height, was the best predictor of % fines. / Ph. D.

Acid mine drainage (AMD), a result of oxidation of minerals containing reduced forms of sulfur (pyrites, sulfides) upon exposure to water and oxygen, is an environmental problem associated with abandoned mined lands (AML). Numerous studies have documented the impacts of AMD upon aquatic communities within acidified stream reaches; these impacts include reduced taxonomic richness and abundance, and/or a shift from pollution sensitive to pollution tolerant species. This dissertation comprises a number of integrative assessments and experiments conducted to investigate the nature of AMD ecotoxicity in the upper Powell River watershed. Emphasis was placed upon bioassessment methodologies and AMD impacts beyond the zone of pH depression. Major findings and processes developed included: 1) an Ecotoxicological Rating (ETR) system was developed that integrates chemical, toxicological, and ecological data into a single value depicting the relative environmental integrity of a given station within a watershed; 2) water column chemistry rather than sediment toxicity was the major factor causing acute toxicity to aquatic biota in close proximity to AMD discharges; 3) solid ferric hydroxide can cause acute toxicity to standard test organisms in the absence of dissolved iron; 4) Asian clams (Corbicula fluminea) can be used to detect both acutely toxic AMD inputs and nutrient loading in low order streams, and clam responses of survival and growth reflect those of indigenous communities to the two contaminant types; 5) aluminum (Al) in transition from acidic to neutral pH waters can cause acute toxicity to aquatic invertebrates, and may be the cause of impaired benthic macroinvertebrate communities in neutral pH (>7.0) waters downstream of an acidic tributary; 6) in the larger river system (North Fork Powell and Powell mainstem), urban inputs appear to have a greater influence upon aquatic communities than metal loading from AMD impacted tributaries; 7) the use of individual level assessment endpoints, such as Asian clam growth in in situ toxicity tests, eliminates variables that may confound attribution of community level impacts to contaminants; and 8) the near elimination of predatory stoneflies (Plecoptera) downstream of the Stone/Straight Creek tributary to the North Fork Powell River was associated with water column Al concentrations. This research was funded by the Virginia Department of Mines, Minerals, and Energy, Division of Mined Land Reclamation, and by the Powell River Project. / Ph. D.

Agriculture, urbanization, and human activities, if not managed carefully, can expose a water body to environmental degradation, decreased water quality, and ultimately impaired benthic macroinvertebrate assemblage conditions. In streams where the benthic macroinvertebrates are impaired, the stream itself will not be meeting the water quality standards set forth in the Clean Water Act. As a result, the goal of this study was to establish relationships between benthic macroinvertebrates and their stressors so that stressor levels that would not adversely impact the benthic macroinvertebrates could be determined. Stressors such as sediment, habitat, water quality, landuse, watershed characteristics, and livestock numbers impact the benthic macroinvertebrate assemblage conditions. Since sediment is recognized as the Nation's leading pollutant and since the benthic macroinvertebrates live in the sediment on a stream bottom, this study placed emphasis upon the investigation of sediment as a primary stressor to the benthic macroinvertebrates. The specific objectives of this study were to develop relationships between the benthic macroinvertebrates and sediment and other stressors for Virginia streams, to evaluate the accuracy of the stressor/benthos relationships, and to discuss the implications of the study results for development of benthic TMDLs. A procedure to determine the relationships between stressors and benthic macroinvertebrate assemblage conditions was developed. Existing data on sediment, habitat, water quality, landuse, watershed characteristics, livestock numbers, and benthic macroinvertebrate assemblage conditions were compiled for 34 stations with 105 samples collected from the fall of 1996 to the fall of 1998. The 34 stations were located within 13 counties in Virginia (Rockbridge, Rockingham, Augusta, Frederick, Shenandoah, Page, Loudoun, Fairfax, Prince William, Fauquier, Culpeper, Rappahannock, and Madison) and in watersheds dominated by agricultural, urban, and forested landuses. Virginia currently uses the Rapid Bioassessment Protocol (RBP) method in its Biological Assessment Program. The RBP compares habitat and biological measures of the benthic macroinvertebrates to reference conditions using individual metrics. VADEQ's Biomonitoring Database, together with Ambient Water Quality Monitoring reports, GIS data layers, and VADCR's Hydrologic Unit Animal Census Database provided all of the necessary information for the stressor variables and benthic macroinvertebrate conditions. Accordingly, the stressor/benthos relationships were evaluated using statistical analyses procedures such as forward, backward, and stepwise multiple regression techniques; correlation analysis; principal component analysis; and r-square analysis. The statistical results indicated that sediment alone cannot be used to assess the benthic macroinvertebrate assemblage conditions. Other stressors such as dissolved oxygen, flow, % urban land, total suspended solids, temperature, stream velocity, substrate, hardness and alkalinity greatly impact the benthic macroinvertebrate assemblage conditions. The study results also indicate that the individual metrics within the RBP procedure are just as critical as the final RBP values in describing the benthic macroinvertebrate assemblage conditions. Upon completing the steps needed to develop stressor/benthos relationships, the validity of the relationships were verified for their application to other streams in Virginia. Validation was completed using 10 stations with 29 samples from the fall of 1996 to the fall of 1998. The 10 stations were located within 8 counties in Virginia (Bedford, Montgomery, Pulaski, Giles, Botetourt, Albemarle, Orange, and Culpeper) and in watersheds dominated by agricultural, urban, and forested landuses to correspond with the stations used to develop the stressor/benthos relationships. The implications of the relationships with regard to TMDLs were also studied using total suspended solids (TSS) loadings, turbidity levels, and embeddedness levels as the stressors of concern. The results for all benthic stations within Virginia showed that moderately impaired streams generally need to reduce the amount of embeddedness by 11, reduce turbidity levels by 5 FTU (57%), and reduce TSS values by 7 mg/L (68%) to meet a threshold value that would no longer adversely impact the benthic macroinvertebrates. Similarly, for the severely impaired stations throughout Virginia to meet threshold values, embeddedness amounts need to be reduced by 22, turbidity reduced by 57 FTU (93%), and TSS reduced by 74 mg/L (96%). This study was important since the proposed stressor/benthos relationships can provide policymakers with a useful tool to determine stressor thresholds that will not adversely impact the benthic macroinvertebrate assemblage conditions for use in developing benthic TMDLs in Virginia. The stressor/benthos relationships could also be used to determine the impact of certain activities or stressors on the benthic macroinvertebrates assemblage conditions in a given stream. / Master of Science

Hollow fills are composed of excess spoil and debris produced from surface coal mining that is not returned to the original mined site. Hollow fills are often constructed in the head of hollows nearby or adjacent to the mined land area, which may be the origins of headwater streams or drain into low order systems. Eleven hollow fills were utilized in evaluating the influence fill drainages had on low order streams in Virginia and West Virginia. The study was conducted in six watersheds including; Five Mile Creek in Mingo County, West Virginia, Trace Fork in Mingo County, West Virginia, Lavender Fork in Boone County, West Virginia, Middle Creek in Tazewell County, Virginia, South Fork of the Pound River in Wise County, Virginia, and Powell River in Wise County, Virginia. Bioassessment procedures used in the evaluation of hollow fill drainages included water/sediment chemistry, acute water column toxicity testing using <i>Ceriodaphnia dubia</i>, chronic sediment toxicity testing using <i>Daphnia magna</i>, benthic macroinvertebrate surveys, and <i>in situ</i> Asian clam (<i>Corbicula fluminea</i>) toxicity testing. Common significant differences in water quality between reference and fill influenced sites, among all watersheds, were elevated conductivity and water column metal concentrations, particularly aluminum and copper. Water column and sediment toxicity testing reported limited significant mortality or reproductive impairment associated with hollow fill drainages. The West Virginia watersheds used in the study consisted of headwater streams originating directly from the settling ponds, placed at the base of the hollow fills, receiving drainages from the fills. Benthic macroinvertebrate analysis reported no significant alteration in total taxa or EPT richness downstream of the ponds. Yet, collector filterer populations, including benthic macroinvertebrates and <i>in situ</i> Asian clams, were enhanced directly downstream of the ponds due to organic enrichment originating from the ponds. A decrease in collector filterer populations and lowered clam growth suggested the organic enrichment dissipated downstream from the ponds. Chlorophyll <i>a</i> analysis of the phytoplankton community was not significantly related to the enhance collector filterer populations in the streams, however the high concentrations in the settling ponds suggest abundant algal communities. The hollow fills evaluated in Virginia drained into receiving systems, whose headwater origins were not directly related to hollow fill drainages. Low taxa richness was associated with the hollow fill and settling pond drainages, however receiving system sites were minimally influenced. Yet, as reported in the West Virginia watersheds, the settling ponds input organic enrichment that enhanced collector filterer populations, including benthic macroinvertebrates and <i>in situ</i> test clams. An analysis of the hollow fills' age, or maturity, reported no significant difference between young and old fills. In general, a common feature of among the various aged fill drainages was elevated conductivity, compared to reference sites of the watersheds. / Master of Science

This study compared physical characteristics used when selecting comparison (healthy) watersheds for the All-Forested Load Multiplier (AllForX) Approach, and examined a quantitative watershed characteristic as a selection criterion. The AllForX Approach uses a regression relationship between Virginia Stream Condition Index (VSCI) scores and AllForX values (a unit-less multiplier that is the ratio of a modeled existing sediment load divided by a modeled all-forested load condition) for an impaired watershed and several comparison watersheds to develop sediment TMDL target loads. The Generalized Watershed Loading Function (GWLF) model was used to simulate sediment loads for 20 watersheds (four impaired and 16 comparison) in the Upper James and New River basins in Virginia's Ridge and Valley physiographic region. Results suggest that within Virginia's Ridge and Valley physiographic region it may be possible to select comparison watersheds that are of a different stream order (watershed size) and lie in different river basins from the impaired watershed. Results further indicated that the topographic index (TI) distributions were not different across the modeled watersheds, indicating the watersheds are hydrologically similar. These results support selecting comparison watersheds regardless of river basin or stream order within Virginia's Ridge and Valley physiographic region. Finally, there was no statistical difference between the AllForX regressions when using the entire period of record or the two most recent VSCI data points. Therefore, for the watersheds modeled for this study, either all of the VSCI samples or the two most recent may be used in the AllForX Approach. / Master of Science

I investigated the relationships between historical and contemporary land cover and macroinvertebrate communities, water quality, and nutrient levels in 10 streams in a historically agricultural region of the Virginia Piedmont. Historical (1963) and contemporary (2011) impervious surface, open area, and forested cover were evaluated using aerial photos and GIS data. Macroinvertebrates were collected in the fall of 2012 and spring of 2013. Water quality parameters (temperature, conductivity, alkalinity, hardness, and DO) and nutrient concentrations (NH3+NH4, PO4-P, NO3-N, Cl, and SO4) were measured at each site. Overall, forest cover decreased by 6.29%, open area decreased by 1.46%, and impervious surface increased by 4.83% from 1963 to 2011. Macroinvertebrate communities were explored using Principal Coordinates Analysis and were found to be significantly related to 2011 percent impervious surface. Water quality parameters were not significantly related to contemporary or historical land cover. Nitrate was negatively related with 2011 forest cover and positively related with 2011 open area; chloride was positively related with 2011 impervious surface and negatively related with 2011 open area. For the 10 watersheds included in this study, contemporary land cover is a better predictor of macroinvertebrate assemblages and nutrient concentrations than historical land cover. / Master of Science