Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range and reductions in Pacific lamprey abundance have been observed in Western North America, and may be indicators of range-wide declines. In the face of declining populations, the U.S. Fish and Wildlife Service has partnered with tribal, state, federal, and local entities to implement a regional Pacific lamprey conservation agreement aimed at reducing threats to Pacific lamprey and improving their habitats and population status. Research needs identified in the conservation agreement include assessing larval Pacific lamprey occupancy and distribution, habitat requirements, and the limiting factors of larval distribution in the freshwater ecosystem. As part of the effort to address these knowledge gaps, we investigated the potential for larval lampreys to occur in tidally-influenced estuarine environments. Research of this type may be valuable for future conservation, management or recovery efforts of Pacific lamprey throughout its range. We employed a two-phased approach, consisting of laboratory and field components to address our aims. We first conducted a series of controlled laboratory experiments to evaluate osmotic stress tolerance and osmoregulatory status of larval Pacific lamprey exposed to a range of (1) fixed salinity in various dilutions of saltwater and (2) oscillating salinity treatments designed to simulate tidal activity. Tolerance was assessed by monitoring and comparing survival of larvae in various treatments through 96 h. Osmoregulatory status was assessed by quantifying and comparing total body water content, plasma osmolality, and plasma cation (i.e., sodium) concentrations among larvae surviving various treatments. In fixed salinity experiments, 100% survival was observed in 0‰, 6‰, 8‰ and 10‰ through 96 h, while 0% survival was observed through 48 h in 12‰, 30 h in 15‰, and 12 h in 25‰ and 35‰. In oscillating salinity experiments, on the other hand, a significant increase in survival (100%) was observed through 96 h in treatments that oscillated between 12‰ and 0‰ (freshwater) at about 6 h intervals versus fixed 12‰ salinity experiments. A significant increase in survival also occurred in oscillating 15‰ treatments (60%) versus fixed 15‰ through 96 h. Linear regression analysis indicated higher environmental salinity in laboratory experiments was significantly related to increases in plasma osmolality and plasma sodium (the most abundant osmotically active plasma cation) concentrations, and concurrent decreases in total body water content among larvae that survived various treatments. Tidal oscillations in salinity appeared to temper the desiccating effects of salinity, as changes in body water content and sodium ion concentration were less abrupt than fixed salinity treatments. These results suggest larvae cannot osmoregulate in hyperosmotic environments, but are able to tolerate some fixed and oscillating hyperosmotic salinity exposure. Consequently, larvae may be able to occur in certain areas of estuaries, such as oligohaline habitats that are characterized by low levels of salinity. Experimental results were used, in part, to guide larval sampling in a tidally-influenced habitat. Occurrence of larval Pacific lamprey and Lampetra spp. (western brook and river lampreys) was subsequently investigated across a gradient of salinity in Ellsworth Creek (Pacific County, Washington) by electrofishing. Larval Pacific and Lampetra spp. were detected within an approximately 300 m long tidally-influenced segment of the study area. Salinity monitoring was conducted in six tidally-influenced reaches where larvae were detected for up to 14 d following electrofishing. Maximum tidal cycle salinity exceeded 15 ppt during 52% to 80% of tidal cycles within tidally-influenced reaches where larvae were detected. These results suggest potential for larval lamprey to occur in certain portions of tidal estuaries. However, long-term residence of larvae in tidally-influenced habitats and whether larvae are able to subsequently survive, grow, transform, and out-migrate is not known and requires further study. Given the potential for tidally-influenced habitats to be occupied by larvae, assessments of larval occurrence in other areas, such as the lower Columbia River, may be warranted. Knowledge of larval lamprey distribution in estuarine environments may be valuable for habitat restoration, and mitigating potential impacts from dredging and other human disturbances.

In-stream aquatic habitat depends on adequate levels of dissolved oxygen. Human alteration of the landscape has an extensive influence on the biogeochemical processes that drive oxygen cycling in streams. Historic datasets allow researchers to track trends in chemical parameters concomitant with urbanization, while land cover change analysis allows researchers to identify linkages between water quality trends and landscape change. Using the Seasonal Kendall's test, I examined water quality trends in oxygen demand variables during the mid-1990s to 2003, for twelve sites in the Rock Creek sub-watershed of the Tualatin River, northwest Oregon. Significant trends occurred in each parameter. Dissolved oxygen (DO (%sat)) increased at five sites. Chemical oxygen demand (COD) decreased at seven sites. Total Kjeldahl nitrogen (TKN) decreased at five sites and increased at one site. Ammonium (NH3-N) decreased at one site and increased at one site. Multiple linear regression indicates that nitrogenous oxygen demand accounts for a significant amount of variance in COD at ten of the twelve sites (adjusted R2values from 0.14 to 0.73). Aerial photo interpretation revealed significant land cover change in agricultural land cover (-8% for the entire basin area) and residential land cover (+10% for the entire basin area). Correlation results between seasonal oxygen demand data and land cover values at multiple scales indicated that: (I) forest cover negatively influences COD at the full sub-basin scale and positively influences NH3-N at local scales, (2) residential land cover positively influences DO (%sat) values at local scales, (3) agricultural land cover does not influence oxygen demand at any land cover assessment scale, ( 4) local topography negatively influences TKN and NH3-N, and (5) urban runoff management infrastructure correlates positively with COD. Study results indicate that, with the exception of forested land, local scale land cover and landscape variables dominate influence on oxygen demand in the Rock Creek basin. Since DO conditions have improved in these streams, watershed management efforts should emphasize local influences in order to continue to maintain stream health.

No description available.

The purpose of this investigation is to compare the dissolved and suspended organic material in Lake Dallas to that coming into the lake through Pecan Creek.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Lee R. Skabelund / Throughout the history of Kansas City, the Brush Creek Corridor has experienced severe flooding which, on numerous occasions, has resulted in loss of life. This urban stream supports a high profile area of the city. It is located adjacent to what is considered Kansas City’s most elite shopping district, the JC Nichols Country Club Plaza, the University of Missouri - Kansas City urban campus, as well as numerous high density residential units. The stream corridor has been confined due to the encroachment of the surrounding urban environment which has minimized many opportunities for the future management of Brush Creek. There have been many flood control projects but these solutions have not been effective in reducing along the entire corridor. Previous projects have been done in a way that alienates urban dwellers from Brush Creek and does not allow pedestrians to utilize the stream corridor as an effective urban green space. The Brush Creek Corridor can be redesigned to revitalize the existing area by embracing natural ecological processes in order to create a more sustainable urban stream system. Brush Creek can be envisioned in a way that will enhance visitor experience by exposing and revealing the ecological processes to the users without inhibiting the functionality of those natural processes. Four project goals have been identified through research: improve, connect, and educate. In order to achieve the project goals, a set of sites are to be selected from the corridor. A corridor study is done to identify sites by assessing factors related to the site’s ability to improve, connect, and educate. Once the sites have been identified and defined, programming and site design strategies will be implemented to relate to the project goals. The selected sites within the Brush Creek Corridor will be models for experience oriented urban stream design. The project area will harbor healthy ecosystems with integrated pedestrian oriented spaces that connect the corridor, improve environmental conditions, and support environmental education. These projects will be catalysts for experience oriented ecological design solutions throughout the Brush Creek Corridor in the future.

Spatio-temporal variability in groundwater discharge and contaminant fluxes along a channelized stream in western Kentucky Surface and groundwater discharges and contaminant fluxes can vary with time and space depending upon the hydrogeological processes and geological setting of the area of interest. This study examined a ~300-m-long, channelized reach of a first-order perennial stream, Little Bayou Creek, in the Coastal Plain of far western Kentucky during the period October 2010–February 2012. Along the study reach, springs discharge groundwater contaminated by the chlorinated organic compound trichloroethene (TCE) and radionuclide technetium-99 (99Tc) released as a result of past activities at the U.S. Department of Energy’s Paducah Gaseous Diffusion Plant. The study addressed variability in groundwater discharge patterns and contaminant concentrations at various timescales (seasonal, annual, and decadal) and the extent to which the discharge sites are spatially persistent. Understanding patterns of groundwater discharge along a stream can be important for assessing the fate and transport of aqueous contaminants. Groundwater discharge was estimated during baseflow conditions using different mass-balance approaches, including velocity-area and dye-dilution gauging. Discharge fluctuated seasonally but typically increased downstream, indicating the entire study reach to be gaining throughout the year. Discharge rates of individual springs also fluctuated seasonally. Tracer test data were utilized to model flow and transient storage along the reach using the USGS software OTIS-P. Cross-sectional area determined from OTIS-P was similar to that measured by velocity-area gauging. Reach area-normalized discharge fluxes were comparable to values determined by Darcy’s law calculations from a pair of monitoring wells at the downstream end of the study reach. Temperature data acquired from probing along grids in winter and summer, from fiber-optic sensing along the reach in autumn, and from data-loggers and manual measurements in springs were used to delineate focused discharge locations. Comparison of temperature-probing results with prior studies indicated that locations of some springs persisted over a decade, whereas other springs emerged and disappeared. Because the stream is located in unlithified sediments, discharge rates of springs appear to fluctuate with soil piping and collapse along joints in fractured clay. Contaminant concentrations in springs decreased downstream along the reach and were lower than observed during September 1999 – May 2001. The continued occurrence of dissolved oxygen and the absence of TCE daughter products in springs suggest that the decrease in TCE concentrations resulted from the installation of upgradient extraction wells, rather than from intrinsic reductive degradation. KEYWORDS: Contaminant fluxes, trichloroethene, technetium-99, baseflow, temperature probing.

The conservation of freshwater resources is fundamental in supporting modern society and preserving natural habitats and ecosystems. Deterioration of water quality in urban landscapes and loss of municipal water to leaky water distribution infrastructure are two substantial challenges to water-resource sustainability. I examine the geochemistry of streamwater, municipal water, wastewater, soil, and bedrock from the Bull Creek watershed, a rapidly urbanizing watershed in Austin, Texas, to achieve a better understanding of the processes of geochemical evolution as anthropogenically-sourced water recharges natural systems. Urbanization patterns in the Bull Creek watershed have created a contiguous expanse of urban development that covers roughly two thirds of the watershed, whereas the remaining third is rural, enabling direct comparison between urban and rural streamwater from a single watershed. Results indicate that Na, Cl, K, and SO₄ in urban springs and tributaries are elevated more than two-fold in comparison with rural springs and tributaries. A comparison of Sr concentration and Sr isotopic composition for spring and tributary samples indicates that municipal water and wastewater provide a substantial contribution to the urbanized stream branches of Bull Creek. This water is reactive in the subsurface after it leaks from the municipal system, evolving via a pathway of water-rock interaction with limestone. / text

On the basis of three morphological characters (e.g., filament, width, chloroplast number, and type of cell end wall), six filament types of Spirogyra were collected along Bear Creek in the Santa Catalina Mountains near Tucson, Arizona. The occurrence and distribution of filament types showed seasonal and geographical patterns. Filaments were more frequently collected in early summer from pools at lower elevation. Growth of Spirogyra may be influenced by water temperature, pH, and water amount. Most filaments occurred more abundantly while water temperture and pH were relatively high. The number of filament types was greatest at sites with a semi-permanent water supply rather than in temporary and permanent pools. Of the six types of Spirogyra, Type V showed morphological and genetic changes through vegetative growth and sexual reproduction in a clonal culture in the laboratory. After 33 months culturing, a narrower filament-width group (Group II, 22.0 ± 1.1 μm) was produced in the original clone (Group I, 30.9 (+OR-) 0.7 μm). Groups I and II were homothallic and sexually compatible. Zygospores from the cross of I x II yielded germlilngs of Groups I, II, III (27.2 ± 1.0 μm) and a binucleate IV (44.9 ± 0.8 μm). Chromosome counts were: Group I (24), Group II (12), Group III (18), and Group IV (24, one nucleus). Relative nuclear-DNA fluorescence values increased as filament width and chromosome number increased. Cytologically, Group I is a tetraploid, Group II a diploid, and Group III a triploid. Systematically, Groups I, II and III key out to pirogyra singularis, S. communis, and S. fragilis, respectively, using Transeau's monograph on Zygnemataceae. These species are interpreted to be a species complex of S. communis (whose name has priority) with the ancestral haploid (x = 6) missing. Five years after isolation of the original strain in this species complex filaments corresponding to Groups I and II were found at the original collection site. The two field-collected groups were indistinguishable from the laboratory species complex in morphology and chromosome number. Homothallic conjunction within two field width groups yielded progeny similar to those from homothallic conjunction of groups in the laboratory species complex. Filament widths of progeny were generally within the width limits of respective parental groups. The four intergroup crosses between laboratory and field width groups were successful and yielded progeny representing Groups I, II, and III. The similarities in morphology, chromosome numbers, and reproductive behavior of laboratory and field width groups imply that the laboratory species complex of S. communis has a natural counterpart in the field.

No description available.

No description available.