5/21/2015  |   13:30 - 13:45   |  101CD

DISENTANGLING MULTIPLE STRESSOR EFFECTS ON INVERTEBRATE ASSEMBLAGES OF BOREAL STREAMS Catchment land use and other human activities interact to affect the biodiversity of stream ecosystems. Understanding how different stressors individually or in concert affect aquatic communities is needed for river basin management. The North Baltic water district, the most populated area in Sweden (ca 2.9 million inhabitants), was selected as a model system to study the cumulative effects of different stressors on benthic assemblages of streams. A total of 88 streams sampled for benthic invertebrates and water chemistry, and classified according to land use and hydrogeomorphological variables, were included in the study. Agricultural land use was the main pressure, resulting in elevated nutrient levels (mean 48 ± 43 µg TP/L, max 205; mean 428 ± 431 µg NO3-N/L, max 2332), loss of connectivity (61% or 54 sites classified as poor or bad) and alterations in morphology (44% or 39 sites). The response of benthic invertebrate diversity and selected species traits along increasing gradients of exposure to single and combined stressors will be discussed.

Richard Johnson (Primary Presenter/Author), Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden, richard.johnson@slu.se;


David Angeler (Co-Presenter/Co-Author), Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden, david.angeler@slu.se;


Brendan McKie (Co-Presenter/Co-Author), Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden, brendan.mckie@slu.se;


Leonard Sandin (Co-Presenter/Co-Author), Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden, leonard.sandin@slu.se;


Simon Hallstan (Co-Presenter/Co-Author), Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden, simon.hallstan@slu.se;

5/21/2015  |   13:45 - 14:00   |  101CD

CUMULATIVE EFFECTS OF DEVELOPMENT ON NEAR-SHORE BENTHIC MACROINVERTEBRATE COMMUNITIES OF SOUTHERN PRECAMBRIAN SHIELD LAKES The Muskoka River Watershed (Ontario, Canada) was selected by the Canadian Water Network, as a case-study region for the development of a “cumulative effects monitoring framework”. Biomonitoring was identified as a critical part of this framework because it provides biologically relevant (i.e., effects-based) indicators of cumulative effects. Two questions about biological effects were posed: Do benthic community assembly patterns exist in minimally disturbed lakes and streams in the Muskoka River Watershed? Has development altered these assembly patterns? A dataset of catchment attributes (e.g., physiography, land-use), local habitat, water quality, and the taxonomic structure of benthic communities was compiled for 120 lakes and 120 streams. Redundancy analysis (RDA) and variance components analysis were used to describe patterns of community assembly. Results provided evidence about the cumulative effects of cottage development, road building, urbanization, agriculture, and other development-related land-use changes on lakes and streams.

Chris Jones (Primary Presenter/Author), Laurentian University, f.chris.jones@ontario.ca;

5/21/2015  |   14:00 - 14:15   |  101CD

INDIVIDUAL AND CUMULATIVE EFFECTS OF FINE SEDIMENT, NUTRIENT ENRICHMENT, AND INSECTICIDE POLLUTION ON STREAM MICROCOSMS Sedimentation, nutrient enrichment, and insecticide pollution are some of the most pervasive stream ecosystem stressors associated with agriculture. However, despite their common co-occurrence, there is little empirical information about their cumulative impacts on stream communities. We manipulated fine sediment, nutrient, and insecticide (Chlorpyrifos) levels in laboratory stream microcosms to evaluate their individual, pairwise, and three-way effects on aquatic invertebrates, benthic algae biomass, and leaf litter decomposition. Two levels of each stressor (natural, high) were randomly applied to 32 microcosms in a fully crossed factorial design with eight treatments and four replicates. We hypothesized pairwise and three-way stressor combinations would have mostly additive effects and few synergistic and antagonistic interactions. Our results indicate sedimentation was the most detrimental ecosystem stressor, with significant negative effects on leaf litter decomposition and other response variables. Insecticide pollution was the second most pervasive stressor, with important negative effects on invertebrate community and leaf litter decomposition. In agreement with our hypothesis, ecosystem responses to multiple stressor treatments mainly suggested additive interactions.

Ana Chara-Serna (Primary Presenter/Author), Department of Forest and Conservation Sciences, University of British Columbia, ana.chara@forestry.ubc.ca;


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

5/21/2015  |   14:15 - 14:30   |  101CD

IDENTIFYING CRAYFISH METABOLIC PATHWAYS DIAGNOSTIC OF NUTRIENT AND DISSOLVED OXYGEN STRESS Pulse discharges are difficult to capture with community or population based bioindicators; thus, there is a need for effective, fast responding indicators at the molecular level. In this study, we investigated the suitability of the crayfish metabolome as a bioindicator of nutrient or dissolved oxygen (DO) stress by identifying altered metabolic pathways and metabolites. Forty-eight captive Procambarus clarkii were randomly assigned one of six nutrient (high, normal, low) and DO (high, normal, low) treatment groups. After four days of acclimation, crayfish were individually housed in 1.4 L aquariums for a 14 day exposure period. After the exposure period, crayfish were sacrificed, and hepatopancreas, gill, and tail muscle tissues were dissected and immediately frozen in liquid nitrogen. A Bruker Avance 600 MHz spectrometer was used to acquire 1D 1H NMR spectral data. Through multivariate data analysis of the metabolomic spectral data, we expect to identify distinguishable metabolic pathways and metabolites among crayfish subjected to varying nutrient and DO concentrations. The crayfish metabolome may be classified as a holistic, fast responding, and early warning indicator of adverse nutrient and DO concentrations.

Natalie Izral (Primary Presenter/Author), Western University & Canadian Rivers Institute, Department of Geography, London, Ontario, N6A 5C2, nizral@uwo.ca;


Robert B. Brua (Co-Presenter/Co-Author), Environment and Climate Change Canada, 11 Innovation Boulevard, Saskatoon, SK, S7N 3H5, bob.brua@canada.ca;


Joseph M. Culp (Co-Presenter/Co-Author), Environment Canada & Canadian Rivers Institute, Department of Biology, University of New Brunwsick, P.O. Box 4400, Fredericton, NB, E3B 5A3, jculp@unb.ca;


Patricia A. Chambers (Co-Presenter/Co-Author), Environment and Climate Change Canada, 867 Lakeshore Rd., Burlington Ontario, Canada, L7R 4A6, patricia.chambers@canada.ca;


Adam G. Yates (Co-Presenter/Co-Author), Western University & Canadian Rivers Institute, adam.yates@uwo.ca;

5/21/2015  |   14:30 - 14:45   |  101CD

THE FUTURE OF ECOLOGICAL CAUSAL ASSESSMENT When biological monitoring detects degraded biological conditions, causal assessments guide management actions toward factors responsible for the condition. Over the past 20 years, the U.S. EPA has developed methods to help investigators identify causes. The next generation of causal assessment methods will leverage the increased volumes of environmental monitoring data: more stressors at more locations; better temporal resolution from continuous monitors; and more types of biota detected by e-DNA. These data provide the opportunity to improve and streamline causal assessment by developing field-based exposure-response relationships for common stressors and combinations of stressors; matching degraded sites with environmentally similar non-degraded sites; and developing spatial models to better define naturally occurring parameters. These advancements likely will increase the chances of restoring degraded waters because there will be greater confidence in the science, causal explanations, and choice of management actions. DISCLAIMER: The views expressed in this presentation are those of the author and do not necessarily reflect the views or policies of the U.S. EPA

Susan Norton (Primary Presenter/Author), U.S.Environmental Protection Agency, norton.susan@epa.gov;

5/21/2015  |   14:45 - 15:00   |  101CD

SUMMARY OF THE DECONSTRUCTING CUMULATIVE EFFECTS SPECIAL SESSION: WHERE TO FROM HERE? Aquatic bioassessment programmes are typically aimed at the detection and evaluation of the effects of single industrial activities such as mining, agriculture, urban development, hydroelectric development and logging. One of these activities alone can introduce a variety of stressors into the aquatic environment, often in combinations characterised by complex stressor interactions that can make assessment and attribution of adverse effects on these systems challenging. This Special Session brought together researchers from around the globe who have taken on various aspects of this challenge. This paper will summarise the findings of the Special Session presenters, identify common themes among them and knowledge gaps they that they recommend for future research initiatives. Finally, there will be a brief exploration of the continuing challenges cumulative effects pose for researchers and resource managers, particularly with a changing climate.

John L Bailey (Primary Presenter/Author), Ontario Ministry of the Environment and Climate Change, jbailey@laurentian.ca;