SFS Annual Meeting

5/23/2019  |   14:00 - 14:15   |  254 B

A PALEOLIMNOLOGICAL HISTORY OF EUTROPHICATION IN UTAH LAKE Anthropogenic increases of phosphate availability can have negative impacts on lake ecosystems through increased harmful algal blooms, reduced visibility, and reduced macrophyte cover. Utah Lake is a large shallow lake located in north-central Utah and features the hallmark indicators of a turbid eutrophic lake. Despite local debate regarding the cause of eutrophication, there is no empirical record as to whether this lake’s waters were historically clearer and if so, when the transition occurred. We used a paleolimnological approach to identify and reconstruct shifts in macrophyte production and community composition. Preliminary organic carbon, nitrogen, and fossil data indicate a transition in the lake’s recent history marking a shift from macrophyte to phytoplankton dominance. We further use sediment eDNA to explore macrophyte and phytoplankton community shifts associated with the transition. This study will provide a historical framework for the timing of environmental shifts as they may relate to various anthropogenic forcing in the catchment and lake. It will also explore the possibility of an ecological tipping point from a mesotrophic to eutrophic regime in a large, shallow lake.

Soren Brothers (Co-Presenter/Co-Author), Utah State University, soren.brothers@usu.edu;


Janice Brahney (Co-Presenter/Co-Author), Utah State University, jbrahney@gmail.com;


Leighton King (Primary Presenter/Author), Utah State University, leighton.r.king@gmail.com;


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5/23/2019  |   14:15 - 14:30   |  254 B

WILDFIRE AND WATER QUALITY: USING FLUORESCENCE SPECTROSCOPY TO PREDICT THE BIODEGRADABILITY OF DISSOLVED ORGANIC MATTER Megafires are sweeping the western United States, increasing erosion and altering lateral transport of organic matter to surface waters. Burn-mobilized dissolved organic matter (DOM) could influence downstream nutrient loading and eutrophication, depending on DOM biodegradability. Though biodegradability is time-consuming to quantify with lab assays, there is some evidence that DOM biodegradability can be predicted with optical properties. In this context, we coupled incubation experiments with parallel factor analysis (PARAFAC) modeling of fluorescence data to characterize the reactivity and type of DOM present before and after a 610 km2 megafire in central Utah. We used samples spanning an extreme flow event to test the concentration-discharge relationships of DOM biodegradability and optical properties for burned and unburned catchments. We observed large shifts in both composition and biodegradability of DOM for all sites. However, burned catchments had DOM that differed substantially from unburned catchments, potentially due to increased interaction with mineral particles and altered sources due to combustion of surface vegetation. We discuss the reliability of optical properties for predicting DOM biodegradability and how these methods could help quantify biodegradable DOM fluxes that may trigger hypoxia or otherwise alter aquatic food webs.

Leika Patch (Primary Presenter/Author,Co-Presenter/Co-Author), Brigham Young University, leika.patch@gmail.com;


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5/23/2019  |   14:30 - 14:45   |  254 B

NUTRIENT AND TRACE METAL IMPACT ON GREAT LAKES ALGAL GROWTH AND COMMUNITY COMPOSITION Efforts to reduce the frequency and extent of harmful algal blooms (HABs) require knowledge about factors that control algal growth, toxin production, and the community shift to cyanobacterial dominance. While labile N and P fuel primary production, micronutrients play a lesser-understood role as the enzymatic engines that promote rapid and efficient growth and toxin production. Just as algal communities shift seasonally, nutrient and trace metal availability can shape community composition by selecting for specific species. In summer 2017, we completed a mesocosm nutrient enrichment experiment using water collected from four river mouths in Lakes Michigan and Erie. Nutrient treatments were fully factorial and completed in triplicate, including phosphate, ammonia as N, and trace metals (Fe, Zn, Ni, Mo, Mn). Community composition (counts), chlorophyll-a and microcystin production (ELISA) were quantified for each bottle. Preliminary data suggest that microcystin concentrations in algae are decoupled from biomass response to enrichment, and that nitrogen and trace metal addition increases Microcystis spp. abundance. These data demonstrate that a multi-nutrient view of elemental requirements is needed to understand the drivers of HABs in the Great Lakes.

Jordyn Stoll (Primary Presenter/Author), Kent State University, jstoll7@kent.edu;


Andrea Fitzgibbon (Co-Presenter/Co-Author), Kent State University , afitzgib@kent.edu;


David Costello (Co-Presenter/Co-Author), Kent State University, dcostel3@kent.edu;


James Larson (Co-Presenter/Co-Author), U.S. Geological Survey, jhlarson@usgs.gov;


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5/23/2019  |   14:45 - 15:00   |  254 B

NUTRIENT INPUTS MEASURABLY INCREASE SIZE AND DECREASE TIME TO METAMORPHOSIS OF TOADS: A MESOCOSM APPROACH Nutrient input in aquatic ecosystems through runoff is a pressing issue as the impacts of globalization continue. Many land-use types, particularly in agricultural and urban landscapes, involve chemical use that can affect water quality, aesthetics, and native organisms via runoff into surface waters. However, experimental examination of how these inputs impact lentic ecosystem fauna are still underway. Our objective was to examine the influence of Nitrogen (N) and Phosphorus (P), and N+P inputs on American toad (Anaxyrus americanus) survival and time to/size at metamorphosis. In spring and summer 2018 we used outdoor mesocosms and treatments including high and low concentrations of N, P, N+P and control (concentrations based on field survey data from golf course lentic ecosystems) in a randomized design with four replicates/treatment. Our results show addition of N and P alone result in larger toads at metamorphosis, but no significant difference in survival or time to metamorphosis. However, the combination of N+P results in larger metamorphic toads that develop at a faster rate. These data suggest inputs of nutrients could create conditions where organisms at higher trophic levels of lentic ecosystems can benefit.

Joseph Milanovich (Primary Presenter/Author), Loyola University Chicago, jmilanovich@luc.edu;


Michael Vosburgh (Co-Presenter/Co-Author), Loyola University, mvosburgh1@luc.edu;


Isabella Lentini (Co-Presenter/Co-Author), Loyola University Chicago, ilentini@luc.edu;


Martin Berg (Co-Presenter/Co-Author), Loyola University Chicago, mberg@luc.edu;


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5/23/2019  |   15:00 - 15:15   |  254 B

WHEN THE PROBLEM DOESN’T WASH AWAY: PHOSPHORUS BUDGET OF INTERNAL AND EXTERNAL LOADING STUDIES AND NUTRIENT BIOASSAY IDENTIFY WATERSHED RESTORATION GOALS Spring Lake is a drowned river mouth lake that historically has contained some of the highest phosphorus concentrations in western Michigan lakes. A 2005 alum treatment effectively reduced internal phosphorus loading in the lake, although water column concentrations exceeded restoration targets. Internal loading studies conducted in 2005, 2006, 2011, and 2016 suggest alum may be starting to lose effectiveness. Concern that high phosphorus loads may be entering the lake from the surrounding watershed prompted an external loading study of the main tributaries of Spring Lake. The results of internal and external loading studies, combined with work from earlier researchers, were used to estimate total load and generate an annual phosphorus budget for Spring Lake. The proportion of the total load contributed by tributaries more than doubled from 22% pre-alum application to 46% post-alum. A complementary nutrient bioassay in Spring Lake, with a control treatment as well as treatments of 10X ambient concentrations of nitrate, phosphate, and both nitrate and phosphate, indicated that changes in chlorophyll concentration were co-limited by nitrogen and phosphorus; future nutrient management must focus on both nutrients in the Spring Lake watershed.

Maggie Oudsema (Co-Presenter/Co-Author), Grand Valley State University - Annis Water Resources Institute, oudsemam@gvsu.edu;


Alan Steinman (Co-Presenter/Co-Author), Annis Water Resources Institute-Grand Valley State University, steinmaa@gvsu.edu;


Michael Hassett (Primary Presenter/Author), Annis Water Resources Institute - Grand Valley State University, hassetmi@gvsu.edu;


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5/23/2019  |   15:15 - 15:30   |  254 B

ASSESSING TROPHIC STATUS OF A KARST GLACIER LAKE-GAHAR, IRAN Gahar lake is in the center of the protected area of Oshtorankooh (altitude 2360m), Lorestan province, Iran. This lake is a unique "Paternoster" alpine lake with two water body that are connected by a stream. The first section is a shallow pond (Little Gahar Lake) and the second portion (or main water body) is a deep lake (Great Gahar Lake). Since there is not any limnological research on Gahar lake, we assessed trophic status of the lakes during ice-free period between May 2010 and May 2011. We measured physical parameters, water temperature, dissolve oxygen, pH, Secchi depth (transparency) and nutrients including Total Nitrates, Nitrates, Nitrites, Ammonia, Total Phosphorus, Dissolved Phosphate and Silica. Because of differences between two water bodies in depth, we used two different trophy indices. According to Carlson's index or Trophic Status Index, the great Gahar lake belongs to status of Oligotrophic level whereas based on Trophic Level Index the small Gahar lake is eutrophic.

Monir Ghiyasabadi (Primary Presenter/Author), Islamic Azad University, monir.ghiass84@yahoo.com;


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