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SFS Annual Meeting

2021 Detailed Schedule

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ADDRESSING THE CONTRIBUTION OF INDIRECT POTABLE REUSE TO INLAND FRESHWATER SALINIZATION [Oral Presentation]

Shantanu Bhide (Primary Presenter/Author)
Virginia Tech, bhidesv@vt.edu;

Stanley Grant (Co-Presenter/Co-Author)
Virginia Tech, stanleyg@vt.edu;

Abstract: Inland freshwater salinity is rising across many regions of the United States and globally, a phenomenon called the freshwater salinization syndrome (FSS). We explore a potential conflict between managing the FSS and augmenting drought prone water supplies through indirect potable reuse (IPR). IPR has the potential to exacerbate the FSS because salts added to the sewage collection system, or during the treatment process, are not removed by conventional treatment. Here we evaluate the relative contribution of three sources—two rapidly developing watersheds and a wastewater reclamation facility—to rising sodium concentration in a regionally important drinking water reservoir in Virginia. Sodium mass loads from the reclamation facility are comparatively small when evaluated on an annual basis but dominate mass loads to the reservoir during dry weather periods. Across all timescales and sources, sodium concentrations are highest in water discharged from the reclamation facility. Sodium in reclaimed wastewater originates from chemicals used in the treatment process, industrial discharges, human excretion, down drain disposal of drinking water, and sodium-rich household products.

AN ASSESSMENT OF THE SALINIZATION OF U.S. LAKES AND STREAMS FROM PROBABILITY SURVEY DATA [Oral Presentation]

Richard Mitchell (Co-Presenter/Co-Author)
U.S. Environmental Protection Agency, mitchell.richard@epa.gov;

Steven Paulsen (Co-Presenter/Co-Author)
US EPA, Pacific Ecological Systems Division, Corvallis, OR, Paulsen.Steve@epa.gov;

Alan Herlihy (Primary Presenter/Author)
Oregon State University, Alan.Herlihy@oregonstate.edu;

Abstract: The U.S. EPA began the NARS (National Aquatic Resource Surveys) program in 2000 to quantify the status and extent of ecological condition in the Nation’s aquatic resources and to track the changes in these conditions over time. As part of NARS, lakes, streams, and rivers have been sampled using a probabilistic design on a five-year cycle across the conterminous U.S. so that quantitative estimates of the entire population can be made. In recent surveys, 84% of the lakes and 82% of the stream/river length were freshwater using a threshold of <500 ppm salt (conductivity ~700 uS). At the other end of the spectrum, 4% of lakes and 2% of stream/river length were saline (>2000 ppm Salt). Salinity patterns varied between ecoregions, with no lakes or streams in the Northern Appalachians being saline compared to 48% of the lakes and 22% of the streams being saline in the Northern Plains, the ecoregion with the highest proportion of saline systems. Temporal analysis of the data showed little or no change in spatial salinity patterns across surveys from 2000-2019. Comparisons of ecological condition to background salinity levels will also be discussed.

CAN THE ION TRANSPORT CHARACTERISTICS OF DIFFERENT AQUATIC INSECT SPECIES PROVIDE CLUES ABOUT THEIR SENSITIVITIES TO CHANGING SALINITY REGIMES? [Oral Presentation]

David Buchwalter (Co-Presenter/Co-Author)
North Carolina State University, dbbuchwa@ncsu.edu;

Jamie Cochran (Primary Presenter/Author)
NC State University, jkcochra@ncsu.edu;

Abstract: Salinity plays a fundamental role in determining where aquatic species can thrive, but little is known about how physiological traits determine species-specific salinity niches. Concerns are rising about biodiversity losses associated with both the increasing concentrations of major ions in certain areas and decreasing concentrations elsewhere. We are using the radiotracer 22Na in conjunction with ICP-MS to measure uptake and efflux rates and species-specific osmoregulatory characteristics under more dilute conditions. Though most species maintain relatively similar total sodium tissue concentrations, their uptake and efflux rates vary considerably (38 and 156-fold across 9 taxa, respectively). Similarly, the loss of previously acquired 22Na after 9 hours of deionized water challenge varies considerably among species. For example, N. triangulifer lost 44.7% of its 22Na label while Acroneuria sp. lost only 4.8%, showing that permeability differences among taxa can be large. While these studies are in early stages, clear physiological differences in transport dynamics and permeability are emerging among species. Ultimately, these differences may help us understand what role salinity plays in species distribution and how different species may be impacted by changing salinity regimes.

CLASSIFYING FRESHWATER SALINIZATION REGIMES IN RIVERS AND STREAMS DRAINING THE WESTERN UNITED STATES [Oral Presentation]

Joanna Blaszczak (Co-Presenter/Co-Author)
Global Water Center and Department of Natural Resources and Environmental Science, University of Nevada, Reno, jblaszczak@unr.edu;

Betsy Summers (Co-Presenter/Co-Author)
University of New Mexico, shaferbetsy@gmail.com;

Lauren Bolotin (Primary Presenter/Author)
University of Nevada Reno, bolotinljb@gmail.com;

Abstract: Freshwater salinization (FS) is increasing across the globe due to non-point source loading of ions originating from anthropogenic activities such as agricultural and urban land-use. Understanding of decadal trends in FS is improving, but the spatial distributions of the timing, magnitude, and duration of characteristic annual patterns of river salinity and the relationship between annual regime types and catchment attributes remains unclear. We classified annual salinity regimes in rivers draining the western U.S. by clustering daily specific conductance (SC) time series from 244 U.S. Geological Survey (USGS) gages distributed throughout 17 states and two monitoring sites in the Rio Grande, which we flow-normalized (SC/Q) using USGS discharge (Q) data. We found two regimes: cluster 1 (73% of sites) characterized by an early-fall peak in SC/Q, and cluster 2 (28% of sites) characterized by a late-winter or early-spring peak. We used a random forest classifier and found that soil salinity and proportional area of open water were the most important catchment attributes for predicting cluster membership. Our results will improve our ability to predict the timing of excess salinity and inform mitigation of FS impacts on lotic ecosystems.

Counting our losses: Quantifying the effects of increasing salinity on invertebrate taxonomic completeness [Oral Presentation]

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

Abstract: Invertebrates vary widely in their tolerance to increased salinity, with moderate increases favoring some taxa but locally extirpating others. Increasing salinity is a global problem and likely affects the distribution of many invertebrate taxa both directly and indirectly. Though we can predict the effects of increased salinity on individual taxa, we have less understanding of assemblage responses to increasing salinity. To examine how invertebrate assemblages respond to salinity alterations I modeled the proportional taxa losses as a function of increased salinity. I used O/E scores from California as estimates of taxa losses and estimated salinity increases as the difference between observed specific conductivity and the expected natural background. Increased salinity accounted for 25% of the variability in taxa completeness, with each 1 mS/cm increase in conductivity associated with a loss of 10% of expected taxa. Oil/gas extraction were strongly associated with salinity changes (R2 = 0.68) with 1 mS/cm increase in conductivity associated with a 20% loss of expected taxa, but agriculture had only weak effects. Increases in salinity should be assessed during causal analyses as a potentially important stressor on aquatic communities.

FIELD-DERIVED SALINITY TOLERANCES MAY NOT ACCURATELY PREDICT LAB SURVIVAL IN PTERONARCYS CALIFORNICA [Oral Presentation]

Katy Gardner (Primary Presenter/Author)
Utah State University, katy.gardner@usu.edu;

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

Abstract: Increasing salinization of freshwaters threatens freshwater biodiversity. Field data are often used to infer tolerances of different species to salinity and other stressors. However, such correlative observations may not always accurately describe stressor-specific tolerances because many environmental variables naturally covary with one another. Such correlative relationships potentially confound our ability to identify the actual mechanisms influencing species distributions. It is critical to experimentally verify field-derived estimates of species’ environmental tolerances. Long-term, chronic-exposure experiments should be most useful in validating such relationships because they best mimic exposures in nature, but very few such studies have been conducted on freshwater macroinvertebrates. Field-derived estimates of salinity (measured as specific conductivity) imply that the stonefly Pteronarcys californica is restricted to conductivities < 400 µS/cm, but long-term laboratory rearing experiments indicate this species can tolerate much higher salinity levels. Such apparent mismatches might arise if laboratory treatments do not mimic well how the concentrations of specific ions vary across natural streams. Conversely, our results may indicate that field-based measures of salinity may simply be correlated with causal factors that do influence species distributions.

Influx and efflux of sulfate from ambient water in freshwater animals [Oral Presentation]

Michael Griffith (Primary Presenter/Author)
U.S. Environmental Protection Agency, Office of Research and Development, Center for Environmental Measurement and Modeling, Cincinnati, OH 45268, griffith.michael@epa.gov;

Jim Lazorchak (Co-Presenter/Co-Author)
United States Environmental Protection Agency, Office of Research and Development, Center for Environmental Measurement and Modeling, Cincinnati, OH 45268, lazorchak.jim@epa.gov;

Herman Haring (Co-Presenter/Co-Author)
Pegasus Technical Services, Inc., Cincinnati, Ohio 45268, herman.haring@hotmail.com;

Abstract: To investigate how the sulfate anion (SO42-) may be related to the adverse effects associated with elevated ionic concentrations in freshwaters, we measured influx and efflux of SO42- in four freshwater groups represented by a fish Pimephales promelas and three invertebrates: a unionid Utterbackia imbecillis, a crayfish Procambarus clarkii and a mayfly Hexagenia bilineata. Using stable isotope ratios, δ(34S/32S), and S and SO42- concentrations, we measured the SO42- influx rate, net flux, and efflux rate during an exposure of 24-hr from water with two concentrations of 34S-enriched NaSO4. The mean estimates of SO42- influx were positive for all four species, and SO42- influx was greater than 0 for both SO42- concentrations in the fish and mollusk and for the lower SO42- concentration in the crayfish. SO42- efflux and net flux estimates were much more variable than those for SO42- influx, but efflux and net flux were negative for some species by SO42- concentration combinations, which suggests net excretion of SO42- by the animals. These results suggest that uptake of SO42- from ambient waters can result in the adverse effects that have been identified with elevated SO42- in freshwaters.

INSECT BIOMASS AND EMERGENCE SUSTAINED DESPITE MAYFLY DECLINES IN MINING-INDUCED SALINIZED APPALACHIAN HEADWATERS. [Oral Presentation]

Aryanna James (Primary Presenter/Author)
Virginia Tech, aryannaj@vt.edu;

Erin Hotchkiss (Co-Presenter/Co-Author)
Virginia Tech, ehotchkiss@vt.edu;

Daniel McLaughlin (Co-Presenter/Co-Author)
Virginia Tech, mclaugd@vt.edu;

Gregory Pond (Co-Presenter/Co-Author)
USEPA, Region 3, Office of Monitoring and Assessment, pond.greg@epa.gov;

Stephen Schoenholtz (Co-Presenter/Co-Author)
Virginia Tech, schoenhs@vt.edu;

Anthony Timpano (Co-Presenter/Co-Author)
Virginia Tech, atimpano@vt.edu;

Carl Zipper (Co-Presenter/Co-Author)
Virginia Tech, czip@vt.edu;

Sally Entrekin (Co-Presenter/Co-Author)
Virginia Tech, sallye@vt.edu;

Abstract: In Appalachian headwaters, macroinvertebrate diversity declines following mining-induced salinization, but changes to biomass and subsequent emergence remain unclear. Larval biomass may be sustained through replacement by salt-tolerant taxa. However, late instars and pupae may succumb to cumulative stress (e.g., oxygen deprivation, ion regulation, diet alteration), resulting in decreased emergence to riparian habitats and recipient food webs. Therefore, assessments relying on immatures may not fully characterize salinization effects. We predicted that larval and emergent biomass would decouple in response to sulfate-dominated salinity where emergent biomass would decrease disproportionately to benthic biomass as late instars succumb to stress. We also predicted that biomass of salt-sensitive taxa (e.g. Ephemeroptera) would decrease. We sampled macroinvertebrates from riffles of six central Appalachian streams representing a salinization gradient of annual mean specific conductances (25-1460 µS/cm) in August and November 2019 and April 2020. Concurrently, we deployed emergence traps and collected insects for one to three weeks. Preliminary results from November suggest that total benthic biomass was sustained across the salinization gradient but mayfly biomass declined. We will present coupled benthic and emergent metrics as enhanced assessments of material transfer across aquatic-terrestrial interfaces.

PHYSIOLOGICAL PLASTICITY AND ACCLIMATORY RESPONSES TO SALINITY STRESS ARE ION SPECIFIC IN THE MAYFLY, NEOCLOEON TRIANGULIFER [Oral Presentation]

Tatiane Terumi Negrão Watanabe (Co-Presenter/Co-Author)
North Carolina State University, tnegrao@ncsu.edu;

David Buchwalter (Co-Presenter/Co-Author)
North Carolina State University, dbbuchwa@ncsu.edu;

Sarah Orr (Primary Presenter/Author)
North Carolina State University, seorr@ncsu.edu;

Abstract: While freshwater salinization has been correlated with significant declines in aquatic biodiversity, it remains unclear if or how species can acclimate to changing salinity regimes. We used larvae of the parthenogenetic mayfly, Neocloeon triangulifer, to ask how ionic exposure history alters subsequent ionic transport rates by using radiotracers (22Na, 35SO4 and 45Ca). We observed that mayflies reared in dilute control water (16 mg L-1 Na and 23 mg L-1 SO4) and subsequently transferred to elevated salinities (153 mg L-1 Na or 667 mg L-1 SO4) had 2-fold (p<0.0001) and 8-fold (p<0.0001) greater ion uptake rates than mayflies chronically reared in elevated Na or SO4, respectively. These acclimatory ion transport changes provided protection in a 96-hour toxicity bioassay for Na, but not SO4. Interestingly, Ca uptake was uniformly much lower and minimally influenced by exposure history, but was more harmful in the toxicity bioassays. We provide novel light microscopic evidence for Ca damage within the epithelium of the Malpighian tubules (insect primary excretory system) that leads to degeneration and necrosis. We conclude that physiological plasticity to salinity stress is ion specific and provide evidence for ion-specific toxicity mechanisms in N. triangulifer.

Road Salt Legacies: Quantifying Fluxes of Chloride to Groundwater and Surface Water across the Chicago MSA [Oral Presentation]

Kimberly Van Meter (Primary Presenter/Author)
University of Illinois at Chicago, kvanmete@uic.edu;

Erich Ceisel (Co-Presenter/Co-Author)
University of Illinois at Chicago, eceisel2@uic.edu;

Abstract: In the city of Chicago, which receives more than 90 cm of snow annually, thousands of tons of road salt are applied to roadways each winter. While much of the applied salt runs off to nearby waterways during snowmelt events, some percolates to shallow groundwater, affecting public supply wells and leading to elevations of chloride in baseflow. In the present study we have created a spatially distributed chloride mass balance (1995-2015) across the Chicago Metropolitan Statistical Area (CMSA). Our results show that inputs of the two largest sources of chloride, road salt and wastewater, increased by 30% and 35%, respectively, between 1995 and 2005. During the same period, however, riverine chloride loads leaving the CMSA remained essentially flat. Accumulation magnitudes of legacy chloride vary across the CMSA as a function of both chloride inputs and retention rates. While inputs are highest in the city center, where road densities are also high, retention rates are highest in suburban and rural areas, where there are fewer impervious surfaces and road runoff can percolate to groundwater. The present results highlight the importance of legacy chloride to water quality dynamics in North American cities.

SALTING A WATERSHED HAS MORE THAN A SEASONAL IMPACT [Oral Presentation]

Linnea Rock (Primary Presenter/Author)
University of Wisconsin , lrock@wisc.edu;

Abstract: Freshwater salinization is a threat to many surface waters across North America. Understanding local drivers and impacts is necessary to address this threat, but few studies track chloride sources and transport at the watershed-scale. We present a chloride mass balance for two drainage lakes in an urban/agricultural watershed in southern Wisconsin. Chloride concentrations in these lakes have risen from ~1-2 mgL-1 in the 1940s, to ~50-75 mgL-1 at present. For two years, we monitored the lakes and tributaries with grab sampling and in-situ conductivity sensors. These data were combined with historical lake, tributary, and storm sewer data to understand long-term changes. Although there is a significant relationship between urbanization and peaks in chloride concentrations (p < 0.005), loading from tributaries is more dependent on drainage area (p < 0.001) than development or road density (both p > 0.3). Road deicing accounts for ~90% of annual chloride loading; however, elevated year-round concentrations allude to the importance of other sources and the unknown level of legacy chloride. With continued urbanization, chloride contamination could quickly become a problem for freshwater ecosystem functions and services. Focused reduction efforts could decrease or curtail the salinization.

SALTY SUMMERTIME STREAMS: ESTIMATES OF PERCENT SPECIES IMPACTED AND THREAT TO SPECIES AT RISK FROM ROAD SALT [Oral Presentation]

Lauren Lawson (Primary Presenter/Author)
University of Toronto, lauren.lawson@mail.utoronto.ca;

Donald Jackson (Co-Presenter/Co-Author)
University of Toronto, don.jackson@utoronto.ca;

Abstract: Urban freshwaters in north temperate regions exhibit high levels of road salt contamination resulting from extensive use of road de-icing agents and high density of impermeable surfaces within cities. While many field studies of road salt contamination are performed during wintertime, recent studies reveal high chloride concentrations persist year-round. Our study assesses the spatial distribution of chloride in Southern Ontario and quantifies the number of species impacted during the summertime (considered the low season for chloride). Our study results reveal that even in summertime chloride concentrations surpass government guidelines for exposure to freshwater aquatic life. We calculate that at some sites over 2/3 of organisms are impacted by their site-specific chloride concentrations. Summertime is a time of reproduction and growth for many species, and these sensitive life stages are put at risk by elevated chloride levels which can disrupt osmoregulation and be lethal. Moreover, our study region is known as a hot spot for Species at Risk and it is one of the most rapidly urbanizing regions in the world. Therefore, increasing levels of chloride year-round may represent a major factor contributing to the decline of Species at Risk.

Ten years later, how well has the U.S. EPA’s field-based method for conductivity held up? [Oral Presentation]

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

Mark Fernandez (Co-Presenter/Co-Author)
TetraTech, Inc., mark.fernandez@tetratech.com;

Glenn Suter (Co-Presenter/Co-Author)
retired from U.S. Environmental Protection Agency, suterpro@earthlink.net;

Lei Zheng (Co-Presenter/Co-Author)
previously with Tetra Tech, Inc., lei.zheng@hotmail.com;

Abstract: How well has the 2011 U.S. EPA’s field-based method for deriving aquatic life benchmarks for conductivity held up over time? To find out, we examined the assumptions and discriminatory power of genus and community level effects. For genus level effects, we assessed confidence of the response of individual genera, number of occurrences needed for estimating effects, and influence of common and uncommon taxa. For community level effects, we assessed the ability of data sets to estimate the effect level by removing potential confounders such as seasonal influences, and we assessed the discriminatory power of the data set by making genus a random variable in permutation tests. We also critically examined independent studies of specific biological responses and quantitative results in different places with different approaches. On the bases of these analyses, the field-based method works well and can provide a reliable representation of the effects of increased ion concentrations on invertebrates in regions with low natural mineral content. Furthermore, more than ten years of scrutiny and challenges and subsequent research have made the science better and provided additional methods for using field observational data.

THE EFFECTS OF SALINITY AND N:P ON CYANOTOXINS IN A N-FIXING AND NON-N-FIXING CYANOBACTERIA [Oral Presentation]

Nicole Wagner (Co-Presenter/Co-Author)
Baylor University, nicole_wagner@baylor.edu;

Raegyn Taylor (Co-Presenter/Co-Author)
Baylor University, raegyn_taylor@baylor.edu;

Kevin Chambliss (Co-Presenter/Co-Author)
Baylor University, kevin_chambliss@baylor.edu;

Bryan Brooks (Co-Presenter/Co-Author)
Baylor University, bryan_brooks@baylor.edu;

Thad Scott (Co-Presenter/Co-Author)
Baylor University, Thad_Scott@baylor.edu ;

Felicia Osburn (Primary Presenter/Author)
Baylor University, felicia_osburn1@baylor.edu;

Abstract: The effect of increasing salinity on the growth and toxin production/leakage of harmful algal blooms (HABs) has not been widely studied. Coastal regions are beginning to experience how encroaching salt water conditions, due to rising sea levels caused by climate change, are affecting freshwater phytoplankton, with HABs being a key concern due to their ability to produce cyanotoxins. The production of nitrogen (N)-rich cyanotoxins has been shown to increase with N availability to blooms, but N is often the limiting nutrient in coastal marine ecosystems. To test how an increase in salinity will affect both microcystin-LR and cylindrospermopsin concentration both over time and under differing N availabilities, we grew Microcystis and Aphanizomenon in batch cultures for approximately a month under low (4) and high (50) N:P ratio environments. We then simulated flushing events to ocean water (OW) environments by spiking cultures with differing amounts of artificial OW (0-30%) after 21 days of growth. After, we monitored growth, carbon (C) and N stoichiometry, and toxin dynamics for 10 days. Our results suggest that the N:P of growth conditions determines how both time and salinity concentration will influence cyanotoxin production/leakage.

DEICERS, MODERATING IONS, AND THE DYNAMICS OF ACUTE AND CHRONIC CHLORIDE STANDARDS IN A SMALL URBAN STREAM [Poster Presentation]

Todd Royer (Co-Presenter/Co-Author)
O’Neill School of Public and Environmental Affairs, Indiana University, Bloomington, tvroyer@indiana.edu;

Liam Bules (Primary Presenter/Author)
O’Neill School of Public and Environmental Affairs, Indiana University, Bloomington, lfbules@iu.edu;

Abstract: The purpose of this research was to explore the dynamics of chloride pollution from deicers in the context of US EPA guidelines and the State of Indiana acute and chronic chloride water quality standards. US EPA guidelines are fixed values, whereas the Indiana chloride standards are a function of total hardness and sulfate concentration. The study stream is Campus River, a small stream that drains the Indiana University campus. More than 35% of the watershed is impervious surface and numerous storm drains discharge to the stream. We used high-frequency sampling of specific conductivity and discrete sampling of chloride, total hardness, and sulfate to determine exceedances of acute and chronic standards from 2018 to 2021. During winter storms, the Indiana acute chloride standard ranged from 620-717 mg/L due to variation in hardness and sulfate; the chronic standard ranged from 383-444 mg/L. Between October 2019 and February 2021 there were 12 exceedances of the Indiana acute standard and 4 of the Indiana chronic standard, and a peak chloride concentration of 5,817 mg/L. The heavy use of deicers on campus results in chloride concentrations that are harmful to aquatic life.

INSECT EMERGENT BIOMASS DOES NOT DIFFER IN SALINIZED STREAMS [Poster Presentation]

Sarah Turner (Primary Presenter/Author)
Virginia Tech, saraht4@vt.edu;

Taylore Sydnor (Co-Presenter/Co-Author)
Virginia Tech, tsydnor5@vt.edu;

Aryanna James (Co-Presenter/Co-Author)
Virginia Tech, aryannaj@vt.edu;

Daniel McLaughlin (Co-Presenter/Co-Author)
Virginia Tech, mclaugd@vt.edu;

Stephen Schoenholtz (Co-Presenter/Co-Author)
Virginia Tech, schoenhs@vt.edu;

Carl Zipper (Co-Presenter/Co-Author)
Virginia Tech, czip@vt.edu;

Sally Entrekin (Co-Presenter/Co-Author)
Virginia Tech, sallye@vt.edu;

Joseph Girgente (Co-Presenter/Co-Author)
Virginia Tech, joseph92@vt.edu;

Abstract: Aquatic macroinvertebrate diversity has declined in headwater streams of central Appalachia following mining activity, which accelerates weathering and results in elevated bicarbonate and sulfate ion concentrations. Effects of conductivity on emergence of aquatic macroinvertebrates are unclear. We predicted salt-sensitive insect density, richness, and biomass would be lower in streams with elevated conductivity. Emergent insects were collected from six streams with natural and elevated conductivities using quantitative emergence traps over 1-3 weeks in summer, fall, and spring of 2019-2020. Insects were identified to order except for Ephemeroptera, Plecoptera, and Trichoptera were identified to family level. Richness and densities were compared for streams with high and low conductivities. There was no difference in the number of emerged taxa at higher levels of conductivity (700-1400 µS/cm). We found a range of 0-93 individuals per taxon, with Diptera showing the highest density across all samples. Emergent insect density was 45% lower in salinized streams relative to reference streams, but only in the fall 2019. Findings on biomass of benthic macroinvertebrates will be presented that further our knowledge of salinization effects on whole-lifecycle biotic responses.

Soil Salinity in Wetlands: How Much Road Salt Do Stormwater Wetlands Retain? [Poster Presentation]

Daiyanera Kelsey (Primary Presenter/Author)
Kent State University, dkelsey3@kent.edu;

Abstract: During the winter, roads are treated with salt (NaCl) to prevent dangerous accidents resulting from precipitation and cold temperatures. However, road salt contributes to increased salt concentrations in freshwater ecosystems which can harm plants and animals that are adapted to live in freshwater. Preliminary work in the Kinsman-Costello lab has shown evidence that wetlands can remove salt from water and reduce transport of harmful concentrations of salt, but the fate of salt entering urban wetlands is unknown. The project will explore the fate of anthropogenic salt in a local wetland at Kent State University. We hypothesize that anthropogenic salt is stored in wetland soils. The two predictions that come out of this hypothesis is that A) salt concentrations decline along a flow path from the inflow to the outflow and B) soil salt concentrations will be elevated, indicating salt storage. Preliminary results from conductivity loggers suggest an overall decrease in salt concentrations. Comparison of rain gauge data and connectivity data suggest that rain combined with snow melt and heavy road salting, contributed to an increase in salt concentrations. Soil sampling and analysis of salt anion and cation concentrations is ongoing.

Understanding mechanisms of salt transport across a landscape to promote improvements in rangeland health, Northwest South Dakota [Poster Presentation]

Lisa Kunza (Co-Presenter/Co-Author)
South Dakota School of Mines and Technology, lisa.kunza@sdsmt.edu;

Kurt Chowanski (Co-Presenter/Co-Author)
South Dakota School of Mines and Technology, kurt.chowanski@sdsmt.edu;

Dan Heglund (Co-Presenter/Co-Author)
South Dakota School of Mines and Technology, Daniel.Heglund@sdsmt.edu;

Patrick Kozak (Primary Presenter/Author)
South Dakota School of Mines and Technology, patrick.kozak@mines.sdsmt.edu;

Abstract: Rangeland salinization influences soil and water quality across the western United States. Butte and Harding counties in northwestern South Dakota have over 10,000 identified impoundments as primary water sources that may influence or be influenced by regional soil salinity transport and concentration, endangering rangeland health, water quality, and riparian areas used by livestock and wildlife. To evaluate the spatial variability of impoundment and soil salinity, we selected 160 impoundments on public lands across 12 HUC12 subwatersheds. We measured impoundment conductivity, soil conductivity, and characterized soil salt concentrations upgradient and downgradient of each impoundment. To assess upgradient soil salt transport and its influence on impoundment and downgradient soil, we derived physical data about impoundments and their drainage area (impoundment area, impoundment drainage area, percent bare ground impoundment drainage area). Upgradient soil conductivity and impoundment conductivity are correlated, which implies salt transport from upgradient soils to impoundments. Across the study area, downgradient salinity either remained constant or increased in relation to upgradient soil salinity. Clarifying the mechanisms of salt transport that influence rangeland health and water quality degradation will promote improvements in rangeland practices throughout the region.

WETLAND SALINIZATION: CHLORIDE AND SULFATE DYNAMICS IN AN URBAN FRESHWATER WETLAND AND ADJACENT STREAM [Poster Presentation]

Marie Stofan (Primary Presenter/Author,Co-Presenter/Co-Author)
Kent State University, mstofan1@kent.edu;

Anne Jefferson (Co-Presenter/Co-Author)
Kent State University, ajeffer9@kent.edu;

Lauren Kinsman-Costello (Co-Presenter/Co-Author)
Kent State University, lkinsman@kent.edu;

Abstract: Freshwater systems in the U.S. are salinizing in areas of human impact as the result of deicing salt application, infrastructure weathering, and impervious surface drainage. Characteristics of freshwater salinization include increased major ion concentrations and variable water chemistry composition. Though freshwater salinization has been well characterized in streams it is less studied in wetlands, which may have unique signatures of salinization as compared to streams within the same watershed. To characterize freshwater salinization in an urban wetland system, we monitored ion concentrations in a constructed wetland complex consisting of three hydrologically connected ponds, and an adjacent first order stream in an urban watershed for one year. Chloride and sulfate mean and maximum concentrations (n=304) were consistently elevated above typical freshwater values at all sampling sites. Chloride and sulfate were significantly correlated in samples from the adjacent stream (r(34)=0.81, p=<0.05) but not samples from in the wetland complex (r(166) = 0.18, p=0.20). Factors related to the decoupling of chloride and sulfate in the wetland complex include instances of extremely high sulfate concentrations, hydrologic events, sample location along hydrologic flow path, and season of sample collection.