6/06/2017  |   11:00 - 11:15   |  305B

A CASE FOR MODERNIZING WATER QUALITY CRITERIA Methods for establishing Water Quality Criteria for the protection of Aquatic Life in the United States were established in 1985. The US EPA is currently considering modernizing this process. Presently, the only information used to inform criteria is a compilation of single species toxicity bioassay data from a handful of “surrogate species”. Other forms of information are currently not used in criteria development. I will summarize decades of research with trace metals that demonstrates how/why using only data collected from a single methodology fails to provide relevant and important science to best inform water quality criteria development. In particular, I will discuss the importance of relevant toxicity test organisms and protocols, particularly those that consider dietary exposures to bioaccumulative contaminants. I will also discuss the prospects for integrating traditional toxicity bioassays with other laboratory approaches, mesocosm, and field survey data.

David Buchwalter (Primary Presenter/Author), North Carolina State University, david_buchwalter@ncsu.edu;


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6/06/2017  |   11:15 - 11:30   |  305B

AN ECOTOXICOLOGY APPROACH TO RESEARCHING PETROLEUM SPILLS THROUGH MESOCOSMS AND FIELD OBSERVATIONS Oil development has expanded dramatically in the Western United States over the last decade. Associated with the rapid expansion has been an increase in the number of accidental releases into the environment. Here, we explored acute and chronic biological effects of petroleum spills on coldwater streams using data collected from a spill site, as well as data from spills simulated in a mesocosm facility. First, we analyzed stream health indicators across multiple levels of biological organization to identify long-term impacts of a petroleum spill that resulted in a large fish-kill. Histological pathologies in mottled sculpin, Cottus bairdii, and alterations in benthic macroinvertebrate communities were discovered at the spill site and at downstream sites more than two years after the spill occurred. Subsequently, we conducted two mesocosm experiments, using naturally colonized benthic macroinvertebrate communities, to identify short-term impacts of simulated spills. Exposure to simulated spill conditions caused concentration-dependent macroinvertebrate drift and mortality that occurred rapidly after the spills were initiated and at lower concentrations than expected. By utilizing both field observations and mesocosm experimentation we gained insights into consequences of petroleum spills on stream communities using an ecotoxicological weight-of-evidence approach.

Sam Duggan (Primary Presenter/Author), University of Minnesota, sambduggan@gmail.com;


Paula Schaffer ( Co-Presenter/Co-Author), Colorado State University, aluapa@gmail.com;


William Clements ( Co-Presenter/Co-Author), Colorado State University, William.Clements@colostate.edu ;


Pete Cadmus ( Co-Presenter/Co-Author), Colorado Parks and Wildlife, pete.cadmus@state.co.us;


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6/06/2017  |   11:30 - 11:45   |  305B

Recovery of streams from acid mine drainage and evaluating toxic metals threshold ranges for community re-assembly Leviathan mine is an abandoned open-pit sulfur mining operation in the central Sierra Nevada. From times of uncontrolled runoff of acidic metal-contaminated water through clean-up remediation efforts, streams exposed to acid mine drainage (AMD) in this watershed have been monitored using benthic macroinvertebrates. Over time, as removal of metals load using lime treatment and microbial sulfate reduction has become more complete, the ecological state has been recovered at some sites while others remain impaired relative to reference condition. Years of high flow have resulted in degraded biological status when AMD capture has been incomplete and metals loading had increased with runoff. In addition, there are seasonal patterns of recovery evident in fall after the summer treatment season, followed by relapse in the following spring after overwinter periods when sources are not captured. As the metals load is reduced, recovery progresses through different components of community structure, function, and similarity to reference assemblage taxonomic composition. Community reassembly corresponds to predicted effects of cumulative metals toxicity. This study demonstrates recovery at sites furthest from AMD source areas but shows year-around treatment needed to reestablish biological integrity for stream zones nearest the mine.

Dave Herbst (Primary Presenter/Author), Sierra Nevada Aquatic Research Laboratory, University of California Santa Barbara, david.herbst@lifesci.ucsb.edu;


R. Bruce Medhurst ( Co-Presenter/Co-Author), Sierra Nevada Aquatic Research Laboratory, ebbnflow@yahoo.com;


Ned Black ( Co-Presenter/Co-Author), US Environmental Proection Agency, black.ned@epa.gov;


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6/06/2017  |   11:45 - 12:00   |  305B

Are aquatic macroinvertebrate communities vulnerable to engineered nanomaterials? A community composition and bioaccumulation study in outdoor wetland mesocoms Wetlands are frequently exposed to emerging contaminants through wastewater and other anthropogenic sources. Wetlands also are habitat for numerous aquatic insect species as well as birds and other wildlife that consume them when they emerge. We examined the effects of engineered copper (Cu) and gold (Au) nanomaterials on aquatic insect community composition and emergence in wetland mesocosms over nine months. Emerging insects were collected monthly for 7 days. Concentration of nanomaterials in aquatic insects was determined using ICP-MS. Cu and Au treatments suppressed the number of insects emerging from the mesocosms compared to the control treatments. The dominant major groups of all emerging taxa were Diptera (83%), Odonata (10%) and Lepidoptera (3%). These results imply that environmentally realistic concentrations of Cu and Au nanomaterials influence wetland insect emergence. This study highlights the effects of emerging contaminants on naturally colonized insect communities within a controlled experiment.

Brittany Perrotta (Primary Presenter/Author), Baylor University, bperrotta16@gmail.com;


Marie Simonin ( Co-Presenter/Co-Author), Duke University, simonin.marie@gmail.com;


Benjamin Castellon ( Co-Presenter/Co-Author), Baylor University, benjamin_castellon@baylor.edu;


Steven Anderson ( Co-Presenter/Co-Author), Duke University & Ellerbe Creek Watershed Association, sa165@duke.edu;


Cole Matson ( Co-Presenter/Co-Author), Baylor University, Cole_Matson@baylor.edu;


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


Ryan S. King ( Co-Presenter/Co-Author), Baylor University, Ryan_S_King@baylor.edu;


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6/06/2017  |   12:00 - 12:15   |  305B

Mesocosm studies bring order to cryptic ecological responses to contaminants. Ecological responses to anthropogenic stress are cryptic by nature making it difficult to make causal inferences. This is due to the fact that ecosystems are dynamic environments and no single factor can be definitively linked to a specific ecological response. Multiple lines of evidence are a common technique used to decipher ecological responses to contaminants to infer cause and effect associations. Mesocosm experiments are an underappreciated cipher of field data. Here we present a series of case studies demonstrating key scientific attributes of mesocosm experiments. Mesocosm results are reproducible, can provide direct evidence of dose-response relations, and in some cases, identify complex ecological responses such as trophic cascades and effects on multiple life stages. Ecologically relevant exposure scenarios developed in mesocosm studies can be extrapolated to natural ecosystems. Paired field and mesocosm studies provide complementary lines of evidence that act like a lens by which ecosystem complexity is simplified, and provide insight into how to manage problems associated with contamination of freshwater ecosystems.

Travis Schmidt (Primary Presenter/Author), USGS WY-MT Water Science Center, tschmidt@usgs.gov;


Janet Miller ( Co-Presenter/Co-Author), USGS, jmiller@usgs.gov;


Holly Rogers ( Co-Presenter/Co-Author), U.S. EPA, hrogers290@gmail.com;


Christopher Mebane ( Co-Presenter/Co-Author), USGS, cmebane@usgs.gov;


Pete VanMetre ( Co-Presenter/Co-Author), U.S. Geological Survey, Austin, TX, pcvanmet@usgs.gov;


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6/06/2017  |   12:15 - 12:30   |  305B

ENEMY EXACERBATION: EFFECTS OF PREDATOR STRESS ON SULFATE LETHALITY IN FRESHWATER AMPHIPODS The presence of predator cues can influence the response of aquatic organisms to anthropogenic contaminants. This study examined the effects of predator cues on behavior, metabolic rate, and sulfate (as Na₂SO₄) toxicity in amphipods (Gammarus sp). Predator cues included alarm cue (macerated conspecifics) and kairomone from mosquitofish (Gambusia affinis) fed amphipods. Avoidance behavior was quantified by measuring time spent active and sheltering in refuge when amphipods were exposed to cues. Lethality trials (96 h) were performed with amphipods exposed to salt alone and salt + cue (2 h cue exposure/day). Intermittent flow respirometry was used to measure oxygen consumption both during and after exposure to cues. Amphipods responded to both types of cue behaviorally, but toxicity tests only showed an increased response to sulfate when kairomone was present.

Trevor Chapman (Primary Presenter/Author), East Tennessee State University, chapmantl@goldmail.etsu.edu;


Joseph Bidwell ( Co-Presenter/Co-Author), East Tennessee State University, bidwell@mail.etsu.edu;


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