SFS Annual Meeting

5/21/2018  |   09:00 - 09:15   |  310 A

SEWERSHEDS AND WATERSHEDS: NATURAL AND ANTHROPOGENIC DRIVERS OF HYDROLOGY AS WATER QUALITY CONTROLS IN URBANIZED MOUNTAIN HEADWATERS Urbanization adds a layer of complexity to the hydrologic functioning of watersheds, but does not completely overwrite natural hydrologic behavior. We performed synoptic surveys in rivers along the mountain-to-urban transition in watersheds along Utah’s Wasatch Front to characterize the hydrology in the urban systems and identify how the hydrology then controls the biogeochemical functioning of the watersheds. Significant urban impacts to water quality do not appear until several kilometers into the urban environment, where there is evidence of an urban-contaminated alluvial aquifer feeding the stream baseflow. At this location the substantial increase in chloride and nitrate concentrations corresponds to an increase in the C:N of the dissolved organic matter (DOM), suggesting DOC in the subsurface is utilized for microbial denitrification of urban nitrate inputs. There is also a shift in DOM chemistry, as measured by fluorescence, with the mountain DOM having a greater aromaticity than the urban DOM, and opposite seasonal patterns in DOM chemical character. This suggests the possibility of an urban signature in DOM fluorescence measurements, and thus DOM chemistry.

Steven Hall (Co-Presenter/Co-Author), Iowa State University, steven.j.hall@utah.edu;


Dave Eiriksson (Co-Presenter/Co-Author), University of Utah, dave.eiriksson@utah.edu ;


Mallory Millington (Co-Presenter/Co-Author), University of Utah, malmillington@gmail.com ;


Hyrum Tennant (Co-Presenter/Co-Author), Utah State University, hyrumtennant@gmail.com ;


Bethany Neilson (Co-Presenter/Co-Author), Utah State University, bethany.neilson@usu.edu;


Paul Brooks (Co-Presenter/Co-Author), University of Utah, paul.brooks@utah.edu;


Rachel Gabor (Primary Presenter/Author), The Ohio State University, gabor.40@osu.edu;


Presentation:
This presentation has not yet been uploaded.

5/21/2018  |   09:15 - 09:30   |  310 A

BIOTIC RESPONSES TO MULTIPLE THREATS OF URBANIZATION AND DRYING IN HEADWATER STREAMS In developing watersheds, biota in headwater streams are not only influenced by land use disturbance, but also by seasonal drying. We were interested in determining the relative importance of hydrologic permanence and urbanization on macroinvertebrate assemblages and salamander densities. We sampled biota in 10 intermittent streams with 11.7–97.1% urban land cover. The spring of 2008 followed an exceptionally dry summer and had significantly lower macroinvertebrate density (1541 m^-2) compared to the spring of 2007 (4589 m^-2; t = -2.86, p<0.021), but composition was similar among years. Several macroinvertebrate metrics (total richness, EPT richness, % EPT abundance, % Isopoda abundance) were negatively related to % urban land cover, and these relationships held in both years. Few macroinvertebrate metrics were related to hydrologic permanence, suggesting that macroinvertebrates in these temporary habitats have traits enabling their persistence through dry spells. In contrast, densities of the two-lined salamander, Eurycea bislineata, increased with increasing permanence, but were unaffected by urbanization. These results highlight the sensitivity of macroinvertebrates to urbanization of temporary streams, regardless of stream permanence, and emphasize the challenges of managing heterogeneous headwater streams given multiple threats and multiple objectives.

Allison Roy (Primary Presenter/Author), U.S. Geological Survey, Massachusetts Cooperative Fish and Wildlife Research Unit, University of Massachusetts Amherst, aroy@eco.umass.edu;


Hannah Lubbers (Co-Presenter/Co-Author), Clermont County Water Resources, hlubbers@co.clermont.oh.us;


Michael Miller (Co-Presenter/Co-Author), University of California Davis, micmiller@ucdavis.edu ;


Presentation:
This presentation has not yet been uploaded.

5/21/2018  |   09:30 - 09:45   |  

WATERSHED URBANIZATION OVERSHADOWS RIPARIAN CANOPY EFFECTS ON STREAM PERIPHYTON COMMUNITY STRUCTURE AND FUNCTION Benthic periphyton structure and function are critical drivers of stream trophic webs and energy flow. We explored the response of benthic algal communities to varying watershed urbanization and riparian canopy cover in 8 streams in Kentucky, USA by assessing (1) in situ gross primary productivity (GPP), (2) periphyton community composition (PCC), and (3) photosynthetic response of periphyton to light level and nutrients. Greater abundances of green algae (relative to diatoms), higher reach-scale GPP, and decreased photosynthetic rates per unit of biomass were all related to elevated watershed urbanization – attributable in part to higher baseline nutrient levels in the urban streams. In vegetation-shaded reaches, the relative abundance of green algae and reach-scale GPP were suppressed for both urban and reference streams. This effect of canopy cover did not translate to differences in periphyton photosynthetic responses, suggesting that riparian canopy impacted stream productivity primarily by influencing periphyton biomass, rather than by altering photosynthetic properties via shifting PCC. Overall, the effects of urbanization on algal communities and productivity were more marked than the effects of riparian canopy, but could be tempered by the presence of riparian cover.

Jeremy Alberts (Co-Presenter/Co-Author), Environmental Solutions and Innovations, Inc., JAlberts@Envsi.com;


Jake J. Beaulieu (Co-Presenter/Co-Author), United States Environmental Protection Agency, beaulieu.jake@epa.gov;


Miriam Steinitz-Kannan (Co-Presenter/Co-Author), Northern Kentucky University, kannan@nku.edu;


Ishi Buffam (Primary Presenter/Author), University of Cincinnati, ishi.buffam@uc.edu;


Presentation:
This presentation has not yet been uploaded.

5/21/2018  |   09:45 - 10:00   |  

POPULATION DENSITY, URBAN STRUCTURE, AND STREAMS The intensive land use associated with dense human populations is detrimental to local watershed condition. High levels of impervious surface produce elevated runoff and associated nutrient and contaminant loads that contribute to geomorphic instability and degraded ecological structure and function. Exclusion of urban development can therefore protect individual small watersheds. However, at broader regional scales, change in population is a boundary condition driven by external social and economic forces, and the associated land use change depends on the distribution and density of people and commerce. At those scales, high density may have beneficial effects on regional water quality through reduction of urban land footprint, which is appropriately evaluated on a per capita rather than a per area basis. Higher population densities have a variety of other environmental costs (air quality, urban heat island) and benefits (energy efficiency and habitat preservation), and each of these costs and benefits may respond differently to population density and land use intensity. Effective watershed planning will benefit from understanding the tradeoffs among these important ecological values, and how they respond to different patterns of urbanization across different scales.

Jim Heffernan (Primary Presenter/Author), Duke University, james.heffernan@duke.edu;


Presentation:
This presentation has not yet been uploaded.

5/21/2018  |   10:00 - 10:15   |  

THE FRESHWATER SALINIZATION SYNDROME IN SOUTHEASTERN URBAN STREAMS Urbanization increases non-point source loading of major ions into freshwater ecosystems due to the efficient routing of water over surfaces heavily modified by human activities. While this increase in mean concentrations is a commonly documented phenomenon that contributes to the “freshwater salinization syndrome”, the temporal dynamics of baseflow chemistry in urban streams and its relationship to development patterns is less well understood. We analyzed bi-monthly streamwater grab samples and monitored water level and specific conductance at 5-minute intervals at the outlet of 21 watersheds within a narrow range of development intensity (10-25% impervious cover) in the Piedmont Triangle, North Carolina. We calculated the coefficient of variation of specific conductance as a metric of “chemical flashiness” and found that 48% of the variation among catchments of similar development intensity could be explained by catchment road density. Specific conductance was strongly positively correlated with Cl^- and the base cations Na⁺, Ca²⁺, and Mg²⁺ (r > 0.5), and weakest with total dissolved nitrogen concentrations. Ultimately, we show that increased temporal variability in specific conductance is primarily driven by road density in catchments, while baseflow solute chemistry strongly reflects underlying geology.

Joanna Blaszczak (Primary Presenter/Author), University of Nevada, Reno, jblaszczak@unr.edu;


Joseph Delesantro (Co-Presenter/Co-Author), University of North Carolina - Chapel Hill, jmdelesantro@gmail.com;


Dean Urban (Co-Presenter/Co-Author), Duke University, deanu@duke.edu;


Emily Bernhardt (Co-Presenter/Co-Author), Duke University, ebernhar@duke.edu;


Presentation:
This presentation has not yet been uploaded.

5/21/2018  |   10:15 - 10:30   |  310 A

HYDROLOGY AND CHEMISTRY OF URBANIZED HEADWATER STREAMS IN AUSTIN, TX: A CONTEXT FOR ECOLOGICAL EVALUATION Austin Texas has a drainage network of ~ 9,000 km of creeks, of which 40% are small headwaters < 0.25 sq km. In conjunction with this dense network of urban streams, Austin also has a robust stormwater monitoring program that has looked at the hydrology and chemistry of small-area drainages for more than 30 years. Most of this data has been used to report non-point source pollutant discharge relationships and the effects of development on watershed hydrology. More recently there has been a keen interest, both locally in Austin and nationally, in understanding the ecological dynamics of urban headwater systems, and their contributions to the larger context of water resource management. A review of these data suggests that these urban headwater streams are highly variable in their runoff-coefficients, even accounting for impervious cover relationships, particularly for smaller events, and that although some water chemistry constituents can be predicted by impervious cover, many cannot, including nutrients, bacteria and suspended solids. These results help contextualize the diversity of conditions that urban headwaters represent and suggest that they should not be grouped simplistically, as is often the case.

Mateo Scoggins (Primary Presenter/Author), City of Austin, Mateo.Scoggins@austintexas.gov;


Presentation:
This presentation has not yet been uploaded.