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SFS Annual Meeting

2021 Detailed Schedule

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A DIATOM INDEX FOR SOUTHEASTERN US STREAMS [Oral Presentation]

Michael Paul (Primary Presenter/Author)
Tetra Tech, Inc., Michael.Paul@tetratech.com;

Diane Allen (Co-Presenter/Co-Author)
Tetra Tech Inc., Diane.Allen@tetratech.com;

Debbie Arnwine (Co-Presenter/Co-Author)
Tennessee Department of Environment and Conservation, Debbie.Arnwine@tn.gov;

Elizabeth Huff (Co-Presenter/Co-Author)
Alabama Department of Environmental Management, esh@adem.alabama.gov;

Cody Jones (Co-Presenter/Co-Author)
Georgia Department of Natural Resources, Cody.Jones@dnr.ga.gov;

Galen Kaufman (Co-Presenter/Co-Author)
USEPA, kaufman.galen@epa.gov;

Kim Laster (Co-Presenter/Co-Author)
Tennessee Department of Environment and Conservation, kim.laster@tn.gov;

Lydia Mayo (Co-Presenter/Co-Author)
USEPA, mayo.lydia@epa.gov;

Lara Panayotoff (Co-Presenter/Co-Author)
Kentucky Division of Water, lara.panayotoff@ky.gov;

Rebekah Taylor (Co-Presenter/Co-Author)
Alabama Department of Environmental Management, rebekah.taylor@adem.alabama.gov;

Abstract: Diatoms are critical components of stream ecosystems and an important part of the biological community. In addition, diatoms are especially sensitive to a wide range of stressors, especially nutrients. These attributes make them ideal candidates for indicator development and yet, of the three principal assemblages use in bioassessment (algae, invertebrates, fish), algal indicators lag behind in frequency and extent of application. We developed a diatom index for the southeastern US for use in aquatic life use assessment and in nutrient criteria development. We conducted an extensive taxonomic harmonization effort, facilitated by recent national efforts in this regard. We explored potential classification using uni- and multivariate modeling. We generated more than 200 metrics using known diatom traits. We combined those metrics into candidate indices using an all model subsets routine and selected top performing indices that were evaluated for overall discrimination, stressor sensitivity, and robust discrimination across ecoregions. We settled on a set of candidate region-wide indices composed of 8 metrics that reflect general disturbance sensitivity, tolerance, oxygen sensitivity, nutrient sensitivity, and motility. The index had a discrimination efficiency above 73% and ecoregional efficiencies ranging from 60% to 100%.

A NOVEL THIN-FILM METHOD TO IMPROVE ACCURACY OF FLUORESCENCE-BASED PHOTOPHYSIOLOGICAL ESTIMATES IN PERIPHYTIC BIOFILMS: A NUMERICAL AND EMPIRICAL EVALUATION [Oral Presentation]

Leon Katona (Co-Presenter/Co-Author)
Wright State University , katona.2@wright.edu;

Yvonne Vadeboncoeur (Co-Presenter/Co-Author)
Wright State University, yvonne.vadeboncoeur@wright.edu;

Katie Hossler (Primary Presenter/Author)
Wright State University, katie.hossler@wright.edu;

Abstract: Recent studies suggest that photophysiological parameters for intact substrates with depth (e.g. periphytic biofilms, microphytobenthos) are overestimated by pulse-amplitude modulated (PAM) fluorometry. This overestimation stems from depth-integration effects resulting from activation of deeper photosynthesizing layers by an attenuated light signal. Here we propose a novel thin-film technique in which fluorescence is measured on a representative subsample spread evenly on a microscope slide. We compare bias and precision in fluorescence-based estimates using the novel thin-film method and conventional intact biofilms. In line with previous studies, numerical simulations of periphytic biofilms demonstrated substantial reduction in bias with the thin-film method. Key parameters were overestimated for intact biofilms, with relative errors up to 145%, compared to 52% on thin films. Paired empirical observations likewise demonstrated that estimates for intact biofilms were consistently higher (up to 248%, p < 0.001) than for thin films. While bias is reduced, poor subsampling for the thin film may diminish precision. Nonetheless, empirically-based estimates of precision for replicate thin-film and intact measurements demonstrated slight improvement in precision for the thin-film method (e.g. the coefficient of variation for the maximum electron transport rate was reduced 30%, p = 0.009).

DEVELOPING DIATOMS BIOMONITORING FRAMEWORK FOR THE UPPER TANA RIVER WATERSHED IN CENTRAL KENYA [Oral Presentation]

George Gatere Ndiritu (Primary Presenter/Author)
Karatina University, Kenya, gatereg@yahoo.com;

Veronicah Muiruri (Co-Presenter/Co-Author)
National Museums of Kenya, veronica.muiruri@yahoo.com;

Taita Terer (Co-Presenter/Co-Author)
National Museums of Kenya, Nairobi, Kenya, taaita@yahoo.com;

Abstract: The development of a scientific-based biomonitoring framework that is simple and robust enough for use by the general public remains a major limitation for sustainable management of ecosystems. Such a framework should be usable by the general population to support sustainable environmental management targets during rehabilitation and restoration initiatives. This research used diatoms assemblages within the framework of the USA EPA’s Biological Condition Gradient to monitor conditions of aquatic ecosystems in the Upper Tana River (UTR). Data on water quality and diatoms were collected in six major sub-catchments in UTR. Thirty-six sampling sites were established along a disturbance gradient from pristine then moderately to severely human-impacted areas. The Canonical correspondence analysis found significant relationship between diatoms assemblages and water quality parameters of conductivity (F = 2.92, p = 0.01), elevation (F = 1.92, p = 0.01, and moderately turbidity (F = 1.64, p = 0.07). As predicted, diatoms assemblages and water parameters grouped sampling sites along ecological condition gradients and it was possible to selected diatoms associated with pristine sites (BCG tiers 1 and 2) moderately disturbed (tiers 3 and 4) several disturbed sites in BCG tier 5 to 6.

DIAGNOSING THE CAUSES OF ALTERED BIODIVERSITY IN FRESHWATER ECOSYSTEMS: DEVELOPMENT, EVALUATION, AND INTERPRETATION OF A TEMPERATURE-SPECIFIC BIOTIC INDEX [Oral Presentation]

Donald Benkendorf (Primary Presenter/Author)
Utah State University, donald.benkendorf@aggiemail.usu.edu;

Charles Hawkins (Co-Presenter/Co-Author)
Utah State University, chuck.hawkins@usu.edu;

Abstract: Most indices used to assess biological integrity do not identify specific causes of alteration. Biotic indices that measure differences between observed and expected tolerances of multiple taxa to specific stressors could help diagnose causes of biodiversity loss/alteration. Individual species tolerance values (TVs) are typically derived from species-stressor associations observed from field data. We used 6 methods to derive thermal TVs for 290 lotic macroinvertebrate taxa collected at 1954 USEPA NRSA (2008/2009) sites and examined how strongly mean assemblage thermal TVs (MATTVs) were associated with modeled stream temperature. The associations between all 6 MATTVs and site temperature at 302 NRSA 2013/2014 reference sites were similar (r2 range = 0.72–0.75). MATTV associations were weak with other environmental factors (r2<0.23) except for Chloride (r2 = 0.50), which is unlikely a stressor at the concentrations observed (<32 mg/L). We used one set of the TVs to create a temperature biotic index (TBI), which we applied to all 1789 2013/2014 NRSA survey sites. 214 (12%) and 34 (2%) of these sites had TBI values > or < than the 95th and 5th percentiles of reference-site values, respectively, implying thermally altered assemblages at these sites.

Estimating observed-to-expected taxonomic richness in streams and lakes to support existence valuation of biological health [Oral Presentation]

Ryan Hill (Co-Presenter/Co-Author)
US EPA, Pacific Ecological Systems Division, Corvallis, OR, hill.ryan@epa.gov;

Scott Leibowitz (Co-Presenter/Co-Author)
US EPA, Pacific Ecological Systems Division, Corvallis, OR, leibowitz.scott@epa.gov;

Paul Ringold (Co-Presenter/Co-Author)
US EPA, ORD, Western Ecology Division, ringold.paul@epa.gov;

Chris Moore (Co-Presenter/Co-Author)
USEPA, Moore.Chris@epa.gov;

Brenda Rashleigh (Co-Presenter/Co-Author)
US EPA, rashleigh.brenda@epa.gov;

Jessie Doyle (Primary Presenter/Author)
ORISE Research Fellow, jdoyle@csumb.edu;

Abstract: The U.S. EPA is striving to quantify the existence value of biological health in the Nation’s streams and lakes through stated preference (SP) surveys. Through focus groups, we concluded that the public understood observed-to-expected taxonomic richness (O/E) better than other candidate indicators of biological health. To quantify how value varies with proximity to resource, we need spatial interpolations of O/E for all perennial streams and lakes within the conterminous US. To make these interpolations, we used random forest to model O/E with data from the National Aquatic Resource Surveys and StreamCat/LakeCat datasets for the Eastern, Plains, and Western ecoregions. Benthic macroinvertebrates (BMI) and plankton were used for streams and lakes, respectively. The models explained 25-30% of the variation in BMI O/E scores (RMSE: 0.25-0.27) and 13-36% in plankton O/E scores (RMSE: 0.22-0.25). Maps of model residuals showed no visual spatial biases, however, there were noticeable differences in predicted values at ecoregion boundaries. To improve model performances, we are exploring modeling O and E separately, using different modeling algorithms, and including new landscape variables. We will also discuss challenges and solutions for combining model interpolations from streams and lakes.

EXPLORING THE EFFECTS OF THE CLEAN AIR ACT ON STREAM INVERTEBRATE COMMUNITIES [Oral Presentation]

Victoria Martinez Mercado (Primary Presenter/Author,Co-Presenter/Co-Author)
Barry University , vicmer714@gmail.com;

Emma Rosi (Co-Presenter/Co-Author)
Cary Institute of Ecosystem Studies, rosie@caryinstitute.org;

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

Audrey Thellman (Co-Presenter/Co-Author)
Duke University , audrey.thellman@duke.edu;

Abstract: Acid deposition in the northeastern United States is an environmental problem affecting aquatic and terrestrial ecosystems. To protect these ecosystems, the Clean Air Act Amendments of 1990 were passed to achieve a national standard of ambient air quality. Long-term pH data at Hubbard Brook Experimental Forest (HBEF) demonstrate that stream pH has increased; however, there is no comparable examination of stream macroinvertebrate recovery. To explore whether these communities have responded to the Clean Air Act Amendments, we synthesized data from the United States Geological Survey (USGS) and the New Hampshire Department of Environmental Services (NHDES) that contain both pH and stream macroinvertebrate measurements. We found that (1) evidence of acid rain recovery is limited to only 13% of sites, (2) in sites with invertebrate data, Ephemeroptera diversity was higher in slightly alkaline sites than in slightly acidic sites, and (3) many sites with temporally robust pH data did not have invertebrate data. These results suggest we lack sufficient invertebrate data to evaluate the impact of the Clean Air Act Amendments and underscores the importance of long-term invertebrate monitoring regimes.

FROM AMERICA TO AFRICA: PILOTING OF THE BIOLOGICAL CONDITION GRADIENT TO EVALUATE THE EFFECTS OF REHABILITATION AND RESTORATION OF UPPER TANA RIVER IN KENYA [Oral Presentation]

Laban Njoroge (Primary Presenter/Author)
National Museums of Kenya, Lnjoroge@museums.or.ke;

Abstract: One motivation of using living organisms such as macroinvertebrates is their capacity to assess ecological conditions. This study employed macroinvertebrates attributes to a simple monitoring framework within the United States Environmental Protection Agency’s Biological Condition Gradient (BCG). BCG was piloted in Upper Tana River in Kenya with an aim of monitoring the effects of catchment restoration. Water quality parameters and invertebrate samples were collected from the runs and identified up to family level. Using Principal Component Analysis (PCA) sites were grouped according to their water conditions. Macroinvertebrate assemblages in relation to ecological conditions were determined using Canonical Correspondence Analysis (CCA). The most significant factors influencing macroinvertebrates were elevation (F = 2.77, P= 0.01), conductivity (F = 1.94, P = 0.01) and discharge (F = 1.84, p = 0.04). All four CCA axes had a strong relationship between macroinvertebrates and water quality parameters (r = 0.87-0.94). This pilot study in Kenya using macro invertebrates yielded promising results and was consistent with other studies carried elsewhere. The BCG model, showed the potential of identifying taxa indicating various ecological conditions that can be used as indicator taxa in the Upper Tana Rivers.

IMPROVING BIOLOGICAL CONDITION ASSESSMENT ACCURACY BY MULTIMETRIC INDEX APPROACH WITH MICROALGAE IN STREAMS AND LAKES [Oral Presentation]

Bo Liu (Primary Presenter/Author)
Hebei University, liubo3@msu.edu;

Abstract: MMI approach is a broadly used in ecological assessment. Accounting for natural variation and disentangling covariation between natural environmental factors and human disturbance factors are imperative for an accurate assessment. Lots of progress has been made recently on the aforementioned two aspects. Three approaches, a priori classification of sites by regions or typologies, site-specific modeling of expected reference condition and varying metrics in site groups, have been tested in lakes and streams to improve assessment accuracy. All existed studies support that site-specific modeling can efficiently account for natural variation and generate a MMI with good performance. However, until now, no strong evidence has shown that diatom/blue-algae typologies are better than regionalization frameworks on accounting for natural variation either in lakes or in streams. To separate the natural variation explained by site specific modeling from that of varying metrics is necessary for a thorough and accurate evaluation on the valuableness of site-grouping by typologies. Different performance of varying metrics among site groups of streams and lakes was most probably caused by the lack of representativeness of diatom metrics on biological condition rather than the complex multi-stressor gradients in streams and rivers.

Linking emerging insect and eDNA biodiversity to metal concentrations in a small southern Appalachian stream [Oral Presentation]

Drew Reavis (Primary Presenter/Author)
Radford University, dreavis1@radford.edu;

Tara Pelletier (Co-Presenter/Co-Author)
Radford University, tpelletier@radford.edu;

Kristina Stefaniak (Co-Presenter/Co-Author)
Radford University, kroth1@radford.edu;

Jamie Lau (Co-Presenter/Co-Author)
Radford University, jlau@radford.edu;

Abstract: Quantifying aquatic insect biodiversity is essential to aid our understanding of ecosystem processes and implementing adequate conservation strategies. Both field techniques and molecular methods for identifying species have their strengths in quantifying biodiversity. We use both techniques to assess biodiversity in a stream in southwest Virginia, along with analyzing levels of several metals at our sites. Soil values for cadmium, chromium, copper, mercury and lead fall within regulatory limits. Emergence traps were used to collect organisms that emerged from the stream as reproducing adults over a four-week period. Environmental samples (e.g., water, soil) were also collected in order to extract and sequence the eDNA found in the samples. Emerging aquatic insect abundance, richness, and diversity increase over time, as expected. More family richness was detected using eDNA than traditional field sampling; however, many families detected using field techniques were not recovered using eDNA, furthering support that both protocols are necessary for fully documenting biodiversity. Furthermore, we did not have much success in identifying eDNA sequences to species with high sequence similarity, suggesting that invertebrate biodiversity of southwest VA is not well-documented.

LONG-TERM MONITORING REVEALS CONVERGENT PATTERNS OF RECOVERY FROM MINING CONTAMINATION ACROSS FOUR WESTERN WATERSHEDS [Oral Presentation]

William Clements (Primary Presenter/Author)
Colorado State University, william.clements@colostate.edu;

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

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

Michelle Hornberger (Co-Presenter/Co-Author)
U.S. Geological Survey, Menlo Park, CA, mhornber@usgs.gov;

Terry Short (Co-Presenter/Co-Author)
U.S. Geological Survey, Menlo Park, CA, tmshort@usgs.gov;

Abstract: Long-term studies of stream ecosystems are essential for assessing restoration success because they allow researchers to quantify recovery trajectories, gauge the relative influence of episodic events and determine the time required to achieve clean-up objectives. To quantify responses of benthic communities to stream remediation, we integrated results of 4 long-term (20-29 years) assessments of mining-impacted watersheds that were broadly distributed across the western U.S. (California, Colorado, Idaho, Montana). Using a before-after control-impact (BACI) study design we observed significant reductions in metal concentrations and improvements of benthic communities following remediation. Although episodic events changed trajectories, recovery rates were relatively consistent, and streams typically recovered within 10-15 years after remediation was initiated. Differences in recovery among watersheds were likely determined by a number of factors, including the severity of contamination, type of remediation, proximity to upstream sources of colonization and hydrologic variation. Our study illustrates the usefulness of BACI designs for demonstrating cause-and effect relationships between restoration treatments and community recovery. Because these 4 watersheds were among the most severely polluted sites in the western U.S., our study demonstrates the potential for remediation success under the most extreme conditions.

REDUCED RICHNESS AND UNDERLYING ENVIRONMENTAL GRADIENTS CREATE UNIQUE MACROINVERTEBRATE RESPONSES TO WATER QUALITY CHANGES IN MISSISSIPPI ALLUVIAL PLAN STREAMS [Oral Presentation]

Stephen DeVilbiss (Primary Presenter/Author)
United States Department of Agriculture - Agricultural Research Service, stephen.devilbiss@usda.gov;

Jason Taylor (Co-Presenter/Co-Author)
USDA-ARS, Jason.Taylor@usda.gov;

Matt Hicks (Co-Presenter/Co-Author)
United States Geological Survey, mhicks@usgs.gov;

Abstract: Mississippi Alluvial Plain (MAP) streams drain extensive agriculture and are chemically and biologically distinct from other regions of Mississippi. State water quality data showed that MAP streams have elevated alkalinity, conductivity and nutrients and lower macroinvertebrate diversity, potentially reducing the efficacy of traditional biomonitoring approaches within the region. We used threshold indicator taxa analysis (TITAN) to compare macroinvertebrate assemblage responses to water quality gradients between ecoregions in Mississippi. Individual taxa and assemblage responses occurred at higher concentrations for alkalinity, organic carbon and phosphorus but not nitrogen in MAP streams. A large proportion of indicator taxa identified were only responsive in MAP streams suggesting that assemblage responses are driven by unique taxa pools that respond to increasing degradation, but at higher levels than observed in other ecoregions. This information may be useful for setting management goals for MAP streams. However, given widespread habitat degradation within the region, these results should be compared to more sensitive biological communities (e.g., algae or bacteria) that may aid managers ability to measure ecological response to best management practices, particularly in interior MAP streams where local taxa pools may not support recovery of macroinvertebrate assemblages.

Relative importance of two correlated variables on aquatic macroinvertebrate communities in a Colorado Front Range river: selenium and urbanization [Oral Presentation]

Andrew Fayram (Primary Presenter/Author)
City of Loveland, Colorado, andy.fayram@cityofloveland.org;

Abstract: Urbanization and elevated selenium can negatively affect aquatic macroinvertebrate communities. These two factors are often highly correlated in rivers along the Front Range of the Rocky Mountains, USA. Data collected from three sites in the Big Thompson River, CO in six different years between 2007 and 2017 were used to construct a random forest model with an index of urbanization and dissolved selenium levels as predictor variables to determine the most important factor in predicting the status of aquatic macroinvertebrate communities as measured by the Colorado Multi-metric Index (MMI). Based on the percent increase in mean square error variable importance measure, dissolved selenium has a greater influence on MMI scores than the development index. The significant negative linear relationship between MMI scores and dissolved selenium predicts a MMI of 29.2 under the current dissolved selenium standard of 4.6 ug/L, 38.6 under the suggested lower standard of 3.1 ug/L, and 44 under the average dissolved selenium value (2.16 ug/L). Reduction in dissolved selenium would likely improve MMI scores but other factors may limit the maximum achievable MMI in the absence of selenium as the intercept of the relationship is 57.9.

SEASONAL PERIPHYTON RESPONSE TO LOW-LEVEL NUTRIENT EXPOSURE IN A LEAST-DISTURBED MOUNTAIN STREAM, THE BUFFALO RIVER, ARKANSAS [Oral Presentation]

Billy Justus (Primary Presenter/Author)
USGS, Little Rock, AR, bjustus@usgs.gov;

Lucas Driver (Co-Presenter/Co-Author)
USGS, Lower Mississippi-Gulf Water Science Center, ldriver@usgs.gov;

David Burge (Co-Presenter/Co-Author)
Science Museum of Minnesota, dburge@smm.org ;

Abstract: The Buffalo River in Arkansas generally has excellent water quality, but water quality concerns were magnified in 2013 when a large confined animal feeding operation(CAFO)was established in the Big Creek watershed. From June 2017 to February 2019, the U.S. Geological Survey collected monthly nutrient samples and seasonal periphyton samples at a site on Big Creek downstream of the CAFO, two Buffalo River control sites upstream of the confluence with Big Creek, and three test sites downstream of the confluence with Big Creek. Nutrient and periphyton data exhibited more temporal than spatial variability. Although nutrient concentrations were generally highest at the Big Creek site, concentrations at the three test sites were low (near laboratory reporting limits) and rarely exceeded concentrations of the two upstream control sites. Although an index developed with three periphyton metrics suggested that ecological conditions at control sites were slightly more favorable compared to test sites, scouring of periphyton during high flows often exceeded the potential positive effects that low-level nutrients had on productivity. These findings emphasize the importance of data collection across extended temporal scales, particularly when working with low-level nutrient gradients.

SMALL HYDROPOWER PLANTS - SMALL ECOLOGICAL FOOTPRINT? INSIGHTS FROM A MULTI-ANNUAL BACI ANALYSIS IN THE ITALIAN ALPS [Oral Presentation]

Alberto Scotti (Primary Presenter/Author)
Institute for Alpine Environment, Eurac Research, Italy, alberto.scotti@eurac.edu;

Dean Jacobsen (Co-Presenter/Co-Author)
Freshwater Biological Laboratory, University of Copenhagen, Denmark, djacobsen@bio.ku.dk;

Valentin Stefan (Co-Presenter/Co-Author)
Helmholtz Centre for Environmental Research, UFZ, Germany - German Centre for Integrative Biodiversity Research (iDiv), Germany, valentin.stefan@idiv.de;

Ulrike Tappeiner (Co-Presenter/Co-Author)
Institute of Ecology, University of Innsbruck, Austria, ulrike.tappeiner@uibk.ac.at;

Roberta Bottarin (Co-Presenter/Co-Author)
Institute for Alpine Environment, Eurac Research, Italy, roberta.bottarin@eurac.edu;

Abstract: The increasing incentives stemming from numerous initiatives promoting sustainable energy production have led to a global success of small hydropower plants. Nonetheless, the debate about the actual environmental impact of these kinds of structures on the riverine ecosystems has been growing, up to the point that some authors argue that their impact might be greater than that of large hydropower plants. However, a thorough evaluation of a case study following a “Before-After-Control-Impact” (BACI) design has not yet been conducted. Using aquatic macroinvertebrates as a proxy of changes in running-water environments and combining generalized linear mixed model (GLMMs), spatial and temporal beta-diversity quantification and variability assessments, we show that a small “run-of-river” hydropower plant located on a glacier-fed stream in the Italian Alps had no impact on the riverine ecosystem. Our results underline the importance of an unbiased approach to strategic energetic planning, but also the need for decision-makers to pursue informed and empirically based trade-off policies concerning water management issues.

THE INFLUENCE OF LANDSCAPE AND LOCAL FACTORS ON ALLOCAPNIA RICKERI DISTRIBUTION IN ARKANSAS [Oral Presentation]

Brianna Annaratone (Primary Presenter/Author)
University of Arkansas, briannahillebrand@gmail.com;

Camryn Larson (Co-Presenter/Co-Author)
University of Arkansas, calarson@uark.edu;

Ashley Dowling (Co-Presenter/Co-Author)
University of Arkansas, adowling@uark.edu;

Daniel Magoulick (Co-Presenter/Co-Author)
Arkansas Cooperative Fish and Wildlife Research Unit, University of Arkansas, danmag@uark.edu;

Clay Prater (Co-Presenter/Co-Author)
Trent University, prater.clay@gmail.com;

Michelle Evans-White (Co-Presenter/Co-Author)
University of Arkansas, mevanswh@uark.edu;

Abstract: Stoneflies are one of the most threatened aquatic orders globally due to climate change, pollution, and habitat loss. In Arkansas, a group of winter stonefly (Capniidae: Allocapnia) includes multiple species that have not been surveyed since the 1980s because species-level identification requires the rarely-collected adult form. In the 1980s, A. rickeri was one of the most common regional species, and the Ozark-Ouachita region was probably the southwest limit of their range. Thus, climate change, stream habitat loss, and reduced water quality in the region may be causing a range shift. Our study aim was to determine whether current A. rickeri distribution and habitat associations have shifted since the 1980s. More than 40 streams were sampled across 4 Arkansas Ecoregions; each stream was sampled several times across the A. rickeri adult emergence period (November 2020 through March 2021). Watershed land use and hydrologic data were estimated at each sampling site along with collection of local stream habitat variables, and these explanatory variables were then used to fit a logistic regression model of A. rickeri distribution. The updated Ozark-Ouachita distribution map will allow us to determine if any range shifts have occurred.

Towards the Reference Condition Approach 2.0 [Oral Presentation]

Michelle Bowman (Primary Presenter/Author)
Forensecology , michelle.f.bowman@gmail.com;

Abstract: The Reference Condition Approach (RCA) is used to monitor effects of anthropogenic stressors on aquatic ecosystems worldwide. The RCA was designed to identify the most problematic stressors across large geographic scales (e.g., countries). Regional models predict the biological condition of aquatic ecosystems based on their physical and chemical properties. Comparisons of actual and expected biological communities are used to estimate the relative amount of anthropogenic stress. The tendency is to use these models for more site specific evaluations but the accuracy and precision is often less than desired. Examples of monitoring programs across Canada will be used to illustrate elements of data collection and processing, study design, modelling, reference site selection, and bioassessment that show promise in increasing the accuracy and precision of the RCA. Improvements will increase the utility of existing RCA databases and inform the most efficient ways to accumulate new information to assess stress on aquatic ecosystems.

Bioassessment of Riparian Ecosystems After Megafire in Northern Utah [Poster Presentation]

Riley Nelson (Co-Presenter/Co-Author)
Brigham Young University, rileynelson@byu.edu;

Paul Frandsen (Co-Presenter/Co-Author)
Brigham Young University, paul_frandsen@byu.edu;

Anna Eichert (Primary Presenter/Author)
Brigham Young University, annaeichert3@gmail.com;

Abstract: In 2018, a 610-km² megafire complex and residual storms following Hurricane Rosa triggered flash flooding and debris flows throughout the Spanish Fork River (Utah) watershed. This resulted in increased runoff, deposited sediment, and altered water chemistry. Aquatic macroinvertebrates are vital in riparian and terrestrial food webs and are important indicators of ecosystem health. To understand how increasing wildfire occurrence influences macroinvertebrate richness, we compare multiple biomonitoring metrics acquired from data collected from 6 sites in 3-month increments between August 2019 and August 2020. Three sites were burned and 3 sites were unburned. The size of the megafire allows for the testing of multiple hypotheses about ecosystem recovery across elevational diversity and vegetation gradients. We compare macroinvertebrate richness among these sites via morphological classification of subsampled D-net kick samples. We use these data to generate a new understanding of freshwater ecosystem disturbances resulting from large fire complexes and inform watershed management by quantifying the rate of recolonization of burned streams with linkage between riparian ecosystem health and macroinvertebrate abundance. Preliminary findings show no obvious difference between burned and unburned site rank abundance or species richness.