Tuesday, June 6, 2017
14:00 - 15:45

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14:00 - 14:15: / 302A COMPARING SEASONAL PATTERNS OF STREAM MACROINVERTEBRATES IN URBAN STREAMS WITH VARYING STORMWATER CONTROL

6/06/2017  |   14:00 - 14:15   |  302A

COMPARING SEASONAL PATTERNS OF STREAM MACROINVERTEBRATES IN URBAN STREAMS WITH VARYING STORMWATER CONTROL Urbanization decreases the abundance and diversity of macroinvertebrates in streams. Stormwater control measures (SCMs) are implemented to mitigate these impacts and improve overall stream health; however, few data exist quantifying whether SCMs positively influence stream ecosystem function. We investigated seasonal changes in stream macroinvertebrates from 2011 – 2013 in 4 small watersheds (2 urban; 2 suburban) with SCMs in Charlotte, NC. Samples were collected immediately upstream and downstream of the confluence of the SCM outlet and the stream channel and at two additional locations downstream using NC DENR Qual 4 methods. There were differences in community structure among sites indicating that there are factors contributing to the maintenance of local invertebrate communities in each watershed. We tested multiple watershed metrics that quantify the degree of urban impact and SCM mitigation and found that total imperviousness (TI) and not SCM type was a more important variable in predicting total and EPT diversity. While urbanization decreases the abundance and diversity of macroinvertebrates in streams, SCMs play an important role in preventing further macroinvertebrate species loss.

Sandra Clinton, PhD (Primary Presenter/Author), University of North Carolina at Charlotte, sclinto1@uncc.edu;


Colin Bell ( Co-Presenter/Co-Author), Colorado School of Mines, cdbell@mines.edu;


Anne Jefferson ( Co-Presenter/Co-Author), Kent State University, ajeffer9@kent.edu;


Sara McMillan ( Co-Presenter/Co-Author), Purdue University, mcmill@purdue.edu;


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14:15 - 14:30: / 302A MICROPLASTIC DEPOSITION IN STREAMS: INFLUENCE OF POLYMER TYPE AND BIOFILM COLONIZATION

6/06/2017  |   14:15 - 14:30   |  302A

MICROPLASTIC DEPOSITION IN STREAMS: INFLUENCE OF POLYMER TYPE AND BIOFILM COLONIZATION Environmental accumulation of plastic waste is an agent of environmental change that has stimulated a rapidly developing field of research in ecosystems worldwide. River networks are implicated as a primary source of microplastic (i.e., particles <5 mm) to oceans, but there are few measurements of microplastic abundance and dispersal in rivers and streams. We adapted spiraling metrics used for organic matter and solutes to quantify microplastic deposition in an outdoor experimental stream at the ND-LEEF facility. We conducted replicated pulse releases of 3 microplastics commonly found in rivers: polystyrene beads, fragments, and acrylic fibers. For each particle type, we repeated pulses using particles with and without biofilm colonization. We predicted the greatest retention for the densest particles (i.e., acrylic fibers) colonized by biofilms. We placed results in context by comparing deposition rates to ongoing research on microplastic abundance in water, sediment, invertebrates, and fish in Lake Michigan tributaries. Results from this research are the first empirical measurements of microplastic deposition in lotic ecosystems, and will contribute significantly to the broader field of research on the global ecology of plastic waste.

Timothy Hoellein (Primary Presenter/Author), Loyola University Chicago, thoellein@luc.edu;


Arial Shogren ( Co-Presenter/Co-Author), University of Notre Dame, ashogren@nd.edu;


Jennifer L. Tank ( Co-Presenter/Co-Author), University of Notre Dame, tank.1@nd.edu;


John Kelly ( Co-Presenter/Co-Author), Department of Biology, Loyola University Chicago, Chicago, IL, USA, Jkelly7@luc.edu;


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14:30 - 14:45: / 302A EVALUATING MACROINVERTEBRATE COMMUNITY RESPONSES TO IMPERVIOUS COVER IN CALIFORNIA WITH THRESHOLD INDICATOR TAXA ANALYSIS

6/06/2017  |   14:30 - 14:45   |  302A

EVALUATING MACROINVERTEBRATE COMMUNITY RESPONSES TO IMPERVIOUS COVER IN CALIFORNIA WITH THRESHOLD INDICATOR TAXA ANALYSIS Since 2010, new construction in California is required to include stormwater detention and infiltration that is designed to capture rainfall from the 85th percentile of storm events in the region, preferably through green infrastructure. This study used recent macroinvertebrate community monitoring data to determine the ecological threshold for percent impervious cover prior to large scale adoption of green infrastructure using Threshold Indicator Taxa Analysis (TITAN). TITAN uses an environmental gradient and biological community data to determine individual taxa change points with respect to changes in taxa abundance and frequency across that gradient. Individual taxa change points are then aggregated to calculate the ecological threshold. This study used impervious cover data from National Land Cover Datasets and macroinvertebrate community data from California Environmental Data Exchange Network and Southern California Coastal Water Research Project. Preliminary TITAN runs for California’s Chaparral region indicated that both increasing and decreasing taxa had ecological thresholds of <1% watershed impervious cover. Next, TITAN will be used to determine shifts in the ecological threshold after the implementation of green infrastructure on a large scale.

Stephanie Figary (Primary Presenter/Author), ORISE Research Participant at the USEPA EPA/ORD/NHEERL Atlantic Ecology Division, figary.stephanie@epa.gov;


Naomi Detenbeck ( Co-Presenter/Co-Author), U.S. EPA/ORD/NHEERL Atlantic Ecology Division, Detenbeck.Naomi@epa.gov;


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14:45 - 15:00: / 302A URBAN STREAMFLOW SUBSIDIES INFLUENCE RIPARIAN VEGETATION AND SOILS IN A MEDITERRANEAN CLIMATE

6/06/2017  |   14:45 - 15:00   |  302A

URBAN STREAMFLOW SUBSIDIES INFLUENCE RIPARIAN VEGETATION AND SOILS IN A MEDITERRANEAN CLIMATE In Mediterranean climates, urban runoff can dramatically increase streamflow during the summer dry season, sometimes causing intermittent streams to become perennial. We examined the effects of summer streamflow subsidies on riparian soils and vegetation along headwater streams in the metropolitan region of Sacramento, California. Localized dry-season water subsidies in this area create a heterogeneous distribution of perennial and intermittent stream reaches, and we sampled soils and understory vegetation at the stream edge in forty 150-m reaches during summer 2016. We found that perennial reaches supported significantly more live plant cover (p < 0.05) and species richness (p < 0.01) than intermittent reaches, as well as higher levels of soil organic matter (p < 0.001). Greater cover and richness in perennial reaches were due to both native and non-native species, including recognized invasive plants. Promotion of urban water conservation in this area could increasingly restore an intermittent flow regime in small streams. While this change would mimic historical conditions and might limit the spread of some invasive species, it could also limit riparian zone productivity, nutrient retention, and native biodiversity.

Joanna Solins (Primary Presenter/Author), University of California, Davis, jsolins@ucdavis.edu;


Mary Cadenasso ( Co-Presenter/Co-Author), University of California, Davis, mlcadenasso@ucdavis.edu;


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15:00 - 15:15: / 302A FISHING IN THE CITY’S SHADOW: TOWARDS AN UNDERSTANDING OF FISH POPULATION REGULATION IN AN ANGLER-DOMINATED LANDSCAPE

6/06/2017  |   15:00 - 15:15   |  302A

FISHING IN THE CITY’S SHADOW: TOWARDS AN UNDERSTANDING OF FISH POPULATION REGULATION IN AN ANGLER-DOMINATED LANDSCAPE Recreational fisheries are spatially structured social-ecological systems where waterbodies are linked by mobile anglers. It has been hypothesized that the reduction or collapse of fish populations should occur in areas near large aggregations of recreational anglers where harvest pressure is presumed to be greatest. To test this hypothesis, we evaluated the direct and indirect influences of recreational anglers on bluegill (Lepomis macrochirus) and largemouth bass (Micropterous salmoides) fisheries across the landscape using path analysis and structural equation modeling. Across 29 lakes, the impacts and responses of angler numbers and movements manifested differently across the landscape. High angler abundances located near large cities reduced bluegill but not largemouth bass abundances, perhaps owing to anglers participating in the catch-and-release of bass but not bluegill. In contrast, angler movements positively tracked bass abundance, indicating anglers traveled further to lakes with more bass. Angler travel distances were also shortest near large cities. Findings support the hypothesis that large angler populations can reduce fish abundances, but indicate impacts will differ in mixed-stock fisheries.

Scott Collins (Primary Presenter/Author), Illinois Natural History Survey, collscot@illinois.edu;


David Wahl ( Co-Presenter/Co-Author), Illinois Natural History Survey, d-wahl@illinois.edu;


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15:15 - 15:30: / 302A CUMULATIVE EFFECTS OF HEADWATER IMPAIRMENT ON DOWNSTREAM ECOSYSTEMS IN HIGHLY MODIFIED LANDSCAPES

6/06/2017  |   15:15 - 15:30   |  302A

CUMULATIVE EFFECTS OF HEADWATER IMPAIRMENT ON DOWNSTREAM ECOSYSTEMS IN HIGHLY MODIFIED LANDSCAPES Headwater streams contribute important materials to downstream habitats including sediment, nutrients, organic matter, and organisms. As the upstream parts of dendritic river networks, they occupy a substantial proportion of total stream length and watershed area. Despite well-established functional linkages between up- and downstream habitats and biota, less research focuses on predicting cumulative effects of headwater impairment. This is particularly important in urbanizing regions since individual headwaters are small and intermittent, may be considered less important than larger streams, and have less legislated protection. In addition, cumulative effects are likely complex and non-linear with thresholds and synergistic interactions occurring across scales. Predicting downstream responses first requires a multiscale understanding of headwater stream variability. We used a spatially extensive dataset of >1000 headwater streams across an urbanization gradient to explore spatial structure of headwater conditions and their relationship to land use. Our analysis revealed predictive capacity is enhanced by incorporating multiple scales, but that type of spatial structure matters (e.g., overland vs. stream distance). Understanding these complex interactions will allow us to predict how headwater impairment cumulatively impacts downstream benthic macroinvertebrate communities.

Brian Kielstra (Primary Presenter/Author), University of British Columbia, b.kielstra@alumni.ubc.ca;


Les Stanfield ( Co-Presenter/Co-Author), Ecohealth Solutions, les.stanfield@outlook.com;


Lenka Kuglerová ( Co-Presenter/Co-Author), University of British Columbia, leku0004@mail.ubc.ca;


John Richardson ( Co-Presenter/Co-Author), Department of Forest and Conservation Sciences, University of British Columbia, Canada, john.richardson@ubc.ca;


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