Monday, June 5, 2017
11:00 - 12:30

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11:00 - 11:15: / 305B ATTAINING THE GOAL OF MORE “ECO” IN ECOTOXICOLOGY DEPENDS UPON BUILDING CONCEPTUAL BRIDGES BETWEEN OBSERVATION AND EXPERIMENT

6/05/2017  |   11:00 - 11:15   |  305B

ATTAINING THE GOAL OF MORE “ECO” IN ECOTOXICOLOGY DEPENDS UPON BUILDING CONCEPTUAL BRIDGES BETWEEN OBSERVATION AND EXPERIMENT Early papers on development of contaminant guidelines suggested data from nature were desirable but were too complex to be useful. However, understanding of geochemistry, bioavailability, species-specific biological effects, ecological implications and models that tie these together has advanced greatly in the last three decades. This paper will review, with examples, lessons learned in applications of these advances. Linking ecology and ecotoxicology depends upon linking experiment and observations of nature. The historic tension between the reductionist and the naturalist is no longer valid given the understanding that each has brought. Mechanistic understanding is necessary to explain observations and can lead to increasingly powerful models of nature. But data from nature, in turn, are also necessary to validate mechanisms and both validate and calibrate models. Time series are an underused but powerful tool for not only asking questions, but themselves become experiments if appropriately conceived. The bridge to more effective environmental policies lies in a superstructure made up of knowledge from interlinked disciplines like geochemistry, biology and ecology and a roadway that is paved with observations and experiments from all.

Samuel Luoma (Primary Presenter/Author), University of California, Davis, snluoma@ucdavis.edu;


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11:15 - 11:30: / 305B TRACING COAL ASH THROUGH AQUATIC FOOD WEBS

6/05/2017  |   11:15 - 11:30   |  305B

TRACING COAL ASH THROUGH AQUATIC FOOD WEBS Coal combustion residuals (CCRs) represent the second largest waste stream in the United States (~117 million tons in 2015).1 In North Carolina, CCRs chronically released to freshwater ecosystems via permitted effluent streams represent stressor mixtures and contain several constituents of concern (i.e. Se, As, Mn). In the present study, we track the movement of CCR-derived trace elements from abiotic compartments (surface water, sediment, and sediment pore water) to biotic compartments (biofilm, zooplankton, and three fish species) in Sutton Lake, a hydrologically closed lake system adjacent to the Sutton Steam Plant in Wilmington, NC. With these data, we ask “what factors account for differential trace element uptake and transfer through aquatic food webs?” Results are initially compared to a non-CCR receiving reference lake and subsequently to lakes with similar CCR-loading but differing limnology and biogeochemistry. We identify patterns in contaminant distribution and report that subsequent to loading via effluent streams, in which trace element ratios are relatively consistent, CCRs undergo concentration or dilution in an environmental compartment-specific manner. 1 ACAA. 2016. 2015 Coal Combustion Product (CCP) Production & Use Survey Report.

Jessica Brandt (Primary Presenter/Author), Duke University, jessica.brandt@duke.edu;


Richard Di Giulio ( Co-Presenter/Co-Author), Duke University, richd@duke.edu;


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


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11:45 - 12:00: / 305B EXPERIMENTAL APPROACH TO UNDERSTANDING RESPONSES OF SPECIES TRAITS TO METAL CONTAMINATION AND SEDIMENT DEPOSITION AT DIFFERENT SPATIAL SCALES

6/05/2017  |   11:45 - 12:00   |  305B

EXPERIMENTAL APPROACH TO UNDERSTANDING RESPONSES OF SPECIES TRAITS TO METAL CONTAMINATION AND SEDIMENT DEPOSITION AT DIFFERENT SPATIAL SCALES The analysis of how biological traits respond to contaminants and other anthropogenic stressors may allow for comparisons of sites with different taxonomic composition and provide insight into the underlying mechanisms that explain species occurrence. We used species traits to analyze trends in benthic invertebrate colonization over time to both a single stressor (metal-contaminated sediment) and multiple stressors (metal-contaminated and fine sediment) in Colorado, USA, and Gunma, Japan. We observed a greater effect of fine-sediment deposition compared to responses based on taxonomic composition. Traits related to mobility, life history, and ecological niche were better for distinguishing the effects of fine-sediment quality. Dominant taxa also appeared less effective when observing responses to multiple stressors; however, this was not the case when comparing responses to a single stressor. In contrast, traits did not show significant responses to a single stressor across all sites, which supports the hypothesis that availability of refugia and fine-sediment quality are most important for avoiding contaminants. This study demonstrates that community trait based assessments at varying spatial scales are necessary if we are to move forward in developing a universal traits-based approach to improve management strategies in impaired environments.

Brittanie Dabney (Primary Presenter/Author), Colorado State University, brittaniedabney@gmail.com;


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


Yuichi Iwasaki ( Co-Presenter/Co-Author), Toyo University, iwasaki086@toyo.jp;


Shosaku Kashiwada ( Co-Presenter/Co-Author), Toyo University, kashiwada@toyo.jp;


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12:00 - 12:15: / 305B TRACE ELEMENT ACCUMULATION IN DRAGONFLY NYMPHS AND CRAYFISH AS INDICATORS OF CONSTRUCTED WETLAND EFFECTIVENESS

6/05/2017  |   12:00 - 12:15   |  305B

TRACE ELEMENT ACCUMULATION IN DRAGONFLY NYMPHS AND CRAYFISH AS INDICATORS OF CONSTRUCTED WETLAND EFFECTIVENESS The H-02 wetland system was constructed to regulate pH and remove trace metals, particularly Cu and Zn, from an effluent line on the Department of Energy’s Savannah River Site. Six dragonfly nymph genera were used as a biomonitors of bioavailable contaminants throughout the wetland system and two reference wetlands. Crayfish from the receiving stream were also analyzed. Concentrations of 15 elements were evaluated in over 600 whole-body composite samples. Element accumulation varied more among than within genera, suggesting genus to be a reasonable taxonomic level for both spatial and taxonomic comparisons. Spatial variability in trace element accumulation differed among genera. Genera more closely associated with sediments generally accumulated higher contaminant concentrations. Nymph Cu and Zn concentrations in the constructed wetland sites were often elevated above those from reference wetlands. Overall, element accumulation did not follow the expected contamination gradient based on water concentrations throughout the system. Some contaminants accumulated to similar levels above and below the treatment wetlands. Despite reducing water concentrations at base flow discharge, biologically available contaminants are passing though the wetlands. Potential causative factors were identified.

D.E. Fletcher (Primary Presenter/Author), Savannah River Ecology Laboratory-University of Georgia, fletcher@srel.uga.edu;


A.H. Lindell ( Co-Presenter/Co-Author), Savannah River Ecology Laboratory-University of Georgia, lindell@srel.uga.edu;


P.T. Stankus ( Co-Presenter/Co-Author), Savannah River Ecology Laboratory-University of Georgia, stankus@srel.uga.edu;


Gary Mills ( Co-Presenter/Co-Author), Savannah River Ecology Laboratory-University of Georgia, gmills@srel.uga.edu;


D.B. Pitt ( Co-Presenter/Co-Author), Savannah River Ecology Laboratory-University of Georgia, dbpitt@uga.edu;


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12:15 - 12:30: / 305B DISSOLVED ORGANIC CARBON AS A POTENTIAL VECTOR FOR METAL BIOACCUMULATION IN AQUATIC FOOD WEBS

6/05/2017  |   12:15 - 12:30   |  305B

DISSOLVED ORGANIC CARBON AS A POTENTIAL VECTOR FOR METAL BIOACCUMULATION IN AQUATIC FOOD WEBS Understanding factors impacting biotic uptake of toxic metals is critical to predicting effects to aquatic biota. The bioavailability framework used for some metals, including copper, is the Biotic Ligand Model (BLM). Two striking features of the BLM are 1) the model estimates availability from the dissolved phase only, ignoring dietary exposure, and 2) The underlying chemical speciation models predict most dissolved copper is not freely available in the water column, and instead is bound by dissolved organic carbon (DOC). We argue this pool of DOC-bound metal may be available to aquatic organisms which consume DOC via the microbial loop. To test this, we exposed filter-feeding black flies, Simulium vittatum, which use the microbial loop, and shredding amphipods, Hyalella Azteca, which do not, to a gradient of copper concentrations in the presence or absence of labile and recalcitrant DOC. Our data suggest that DOC was protective of copper uptake for Hyalella, but not for Simulium, likely due to consumption of DOC. Collectively, these data suggest DOC is not protective of metal accumulation for all aquatic organisms as the BLM assumes.

Nathan Tomczyk (Primary Presenter/Author), University of Georgia, nathan.tomczyk@gmail.com;


Thomas Parr ( Co-Presenter/Co-Author), University of Oklahoma, Thomas.parr@ou.edu;


Krista Capps ( Co-Presenter/Co-Author), University of Georgia, kcapps@uga.edu;


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