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

REGINAL MONITORING NETWORKS: EXPLORING NATURAL VARIABILITY IN BIOLOGICAL, THERMAL AND HYDROLOGIC DATA AT FRESHWATER WADEABLE STREAMS SITES States, tribes and other entities in the eastern and midwestern US have been working with EPA to collect biological and year-round thermal and hydrologic data at Regional Monitoring Networks (RMNs) sites in freshwater wadeable streams. Building on existing state and tribal bioassessment efforts, RMN surveys have the goal of collecting regionally comparable data on an annual basis at a limited number of sites from a pre-defined class that can be pooled. We present results from preliminary analyses on data that have been collected from a subset of RMN sites representing high quality, medium to high gradient, wadeable streams in the eastern US. First we characterize natural temporal patterns and episodic events in the thermal and hydrologic data. Then we examine natural variability in the biological data and explore associations between these data and variations in the thermal and hydrologic conditions. An understanding of natural temporal and spatial variation in aquatic systems is important because it enables monitoring programs to separate natural variation from human-induced changes.

Britta Bierwagen ( Co-Presenter/Co-Author), US EPA, bierwagen.britta@epa.gov;


Jen Stamp ( Co-Presenter/Co-Author), Tetra Tech, jen.stamp@tetratech.com;


David Gibbs ( Co-Presenter/Co-Author), U.S. Environmental Protection Agency, gibbs.david@epa.gov;


Anna Hamilton (Primary Presenter/Author), Tetra Tech Center for Ecological Sciences, Anna.Hamilton@tetratech.com;


Erik Leppo ( Co-Presenter/Co-Author), Tetra Tech, Inc., erik.leppo@tetratech.com;


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

STREAM SIZE-DEPENDENT SPATIAL AND TEMPORAL PATTERNS IN DIATOM ASSEMBLAGES: EVIDENCE FROM A LONG-TERM STUDY IN MULTI-STRESSOR SYSTEMS Bioassessment is commonly used to evaluate the integrity of rivers and streams, determine changes related to point source discharges, and inform management decisions. Although periphyton chlorophyll a is often incorporated into bioassessment programs, assessment of periphytic diatom assemblages is less common. Using a multi-year (n=13), multi-site (n=5-7/stream), seasonally sampled (spring and fall) dataset, we evaluated spatial and temporal patterns in diatom assemblages relative to non-point sources, and inputs from tributaries and pulp and paper mill discharges in four streams (Codorus Creek, PA; Leaf River, MS; McKenzie and Willamette Rivers, OR) of varying drainage area and land use. Diatom assemblage structure and biotic integrity/diagnostic metrics (e.g. %eutrophic, %sensitive, etc.) differed with stream size. In the larger rivers, significant differences in diatom assemblages occurred between seasons and across years, but spatial differences were rarely observed. In contrast, significant spatial and seasonal differences in diatoms were seen in wadeable Codorus Creek. Associated water quality and habitat measures support the hypothesis that stream size mediates spatial variability in these systems. Findings from this study highlight the value of spatially and temporally comprehensive datasets in elucidating assemblage patterns.

Camille Flinders (Primary Presenter/Author), NCASI, cflinders@ncasi.org;


William Arthurs ( Co-Presenter/Co-Author), NCASI, warthurs@ncasi.org;


Joan Ikoma ( Co-Presenter/Co-Author), NCASI, jikoma@ncasi.org;


Renee Ragsdale ( Co-Presenter/Co-Author), NCASI, rragsdale@ncasi.org;


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

COMPARISON OF THE PERFORMANCE OF FOUR BIOTIC INDEXES DEVELOPED FOR USE ON PUERTO RICO STREAMS Until recently water quality practitioners in Puerto Rico lacked stream bioassessment protocols and indexes that directly assess and report on biological conditions. This was attributed to slow development of biological assessment protocols applicable for Caribbean streams. To evaluate four newly developed biotic indexes, Macroinvertebrate Integrity Index (MII), Percent Model Affinity (PMA), Index Biological Monitoring Working Party (BMWP’PR), and Index Biotic Family (IBF’PR), scores were calculated using macroinvertebrate data collected from the Rio Piedras and other stream sites located throughout the island. Performance of each index was tested to determine differences in the responses along environmental gradients related to land use, water chemistry, and physical habitat. Overall, each index showed a moderate to strong response across these gradients and the responses were generally similar. Conclusions on the sensitivity of each index should be viewed cautiously until index variability is better understood and the indexes are tested on subtle gradients of environmental conditions caused by anthropogenic activities. The macroinvertebrate indexes show potential to determine aquatic life use support, help develop biological criteria, and protect aquatic stream resources in Puerto Rico.

James Kurtenbach (Primary Presenter/Author), USEPA Region 2, kurtenbach.james@epa.gov;


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

ASSESSING ECOLOGICAL HEALTH OF DRY PHASE INTERMITTENT RIVERS AND EPHEMERAL STREAMS Intermittent rivers and ephemeral streams (IRES) can remain dry from weeks to years, making traditional assessment techniques impractical. As perennial river systems become increasingly intermittent worldwide, there is a growing need to develop tools to assess ecological health during the dry phase. We sampled bryophytes and terrestrial arthropods at thirty-nine sites in the San Diego region across environmental and disturbance gradients as potential biological indicators during dry periods. We collected bryophytes within the channel and surrounding riparian zone using a microhabitat-based sampling protocol and arthropods using ramped pitfall traps within the channel. Bryophyte morpho-species richness differed significantly (p < 0.05) between reference and non-reference sites. Several of the 18 arthropod metrics tested also differed significantly, including: ant relative richness and combined beetle and spider relative richness. We expect that accounting for natural variability in metric scores and assessing additional arthropod metrics (e.g. dispersal ability and functional feeding groups) will yield additional sensitive metrics. These initial results suggest that multi-metric indices based on terrestrial arthropods and bryophytes may be used to assess IRES ecological condition when dry.

Matthew Robinson (Primary Presenter/Author), California State University Monterey Bay, marobinson@csumb.edu;


John Olson ( Co-Presenter/Co-Author), Dept of Applied Environmental Science, California State University Monterey Bay, CA, USA, joolson@csumb.edu;


Raphael Mazor ( Co-Presenter/Co-Author), Southern California Coastal Water Research Project, raphaelm@sccwrp.org;


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

EFFECTS OF POST-FLOOD “STREAM CLEANING” ON BENTHIC ORGANIC MATTER STORAGE AND ECOSYSTEM FUNCTION IN THREE NORTHERN APPALACHIAN STREAMS During fall 2011, Tropical Storm Lee produced extensive flooding throughout central Pennsylvania. Widespread property and infrastructure damage led to public outcry to revive a time-honored tradition of “cleaning” streams through channelization and removal of large woody debris. Otherwise pristine mountain streams were altered, providing a unique opportunity to study the effects of channelization on stream ecosystem function in the absence of other anthropogenic stressors. We measured ecosystem metabolism, algal biomass, nutrient uptake and fine benthic organic matter storage in channelized and reference reaches of three streams draining forested catchments. Although channelized sections had less canopy cover, gross primary productivity and algal biomass were not consistently higher in channelized reaches. However, nitrate uptake was up to five times lower in the channelized sections, which corresponded with lower ecosystem respiration and lower fine benthic organic matter. Transient storage measured at the time of the nutrient releases did not explain differences in nitrate uptake. This study suggests that “stream cleaning” reduces a stream’s capacity to retain benthic organic matter, thus reducing microbial demand for nitrate and ultimately leading to greater downstream export.

Steven Rier (Primary Presenter/Author), Commonwealth University of Pennsylvania, srier@commonwealthu.edu;


Meredith Salmon ( Co-Presenter/Co-Author), Bloomsburg University, msalmon@peddie.org;


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

HYDROLOGICAL, ENVIRONMENTAL AND SPATIAL VARIABLES INTERACT TO DETERMINE SPECIES, TRAIT COMPOSITION AND BETA DIVERSITY OF PELAGIC ALGAE Algae based bio-assessments, particularly trait-based approaches, are increasingly used now. However, the contribution of hydrological variables to algal community’s variation has been rarely reported, and the main drivers of species, trait composition and beta diversity are less studied. This study aimed to link species and trait composition to multiple factors (i.e. hydrological, local environmental and spatial variables), and to disentangle the relative importance of distinct factors in shaping species, trait composition and beta diversities of pelagic algae. Both trait and species composition showed significant correlations with hydrological, environmental and spatial variables, respectively. However, trait composition was better explained than species composition by the three factors. Variation partitioning revealed that the hydrological and local environmental variables outperformed spatial variables. Both species and trait based beta diversities were significantly related to hydrological and environmental distances, while the pure spatial distance was shown to be less important. In addition, the decay of community dissimilarities against environmental distance was consistently weaker than hydrological distance, suggesting that environmental filtering did not account for much of the among-site differences in species and trait compositions.

Naicheng Wu (Primary Presenter/Author), Aarhus University, naichengwu88@gmail.com;


Yueming Qu ( Co-Presenter/Co-Author), Kiel University, nwu@hydrology.uni-kiel.de;


Björn Guse ( Co-Presenter/Co-Author), Kiel University, bguse@hydrolog.uni-kiel;


Kriste Makareviciute ( Co-Presenter/Co-Author), Helmholtz Centre for Ocean Research Kiel (GEOMAR), kriste.makareviciute@gmail.com;


Szewing To ( Co-Presenter/Co-Author), Kiel University, stu205208@mail.uni-kiel.de;


Tenna Riis ( Co-Presenter/Co-Author), Aarhus University, nwu@aias.au.dk;


Nicola Fohrer ( Co-Presenter/Co-Author), Kiel University, nwu@daad-alumni.de;


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6/06/2017  |   15:30 - 15:45   |  302C

Understanding Urban Land Use Disturbance in Streams: A comparison of multiple biotic multi-stressor models. In 2014, the U.S. Geological Survey sampled 74 streams across 5 States in the S.E Piedmont of the U.S. Ecological condition of streams were assessed in relation to multiple stressors including streamflow, suspended sediment, nutrients, major ions, dissolved pesticides and degradates, and sediment-associated contaminants. Streams were sampled for algae, macroinvertebrates and fish in late spring under base-flow conditions. Our overall objective was to understand whether aquatic assemblages are responding to multiple stressors in comparable or differential ways and to identify a subset of important indicator stressors for each assemblage. Individual aquatic assemblage were related to multiple stressors using exploratory, statistical and machine learning data analysis techniques including data visualization, correlation and boosted regression modeling, respectively. A secondary objective was to tease out the variability associated with changes in aquatic assemblage condition based solely on land use relative to changes based on specific instream stressors such as habitat, nutrients and contaminants. Such evaluations are explored through model performance by stressor category, comparison of final explanatory variables and stressor assessment across the large urban gradient.

Ian Waite (Primary Presenter/Author), U.S. Geological Survey, Portland, OR, iwaite@usgs.gov;


Mike Meador ( Co-Presenter/Co-Author), U.S. Geological Survey, mrmeador@usgs.gov;


Mark Munn ( Co-Presenter/Co-Author), U.S. Geological Survey, Tacoma, WA, mdmunn@usgs.gov;


Daren Carlisle ( Co-Presenter/Co-Author), U.S. Geological Survey, dcarlisle@usgs.gov;


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