SFS Annual Meeting

5/20/2019  |   11:00 - 11:15   |  254 B

DEVELOPMENT OF QPCR METHODS TO ASSESS THE SPATIAL AND TEMPORAL VARIABILITY OF HARMFUL ALGAL BLOOMS Cyanobacterial blooms are becoming a greater concern in freshwater systems due to their increasing frequency and potential to produce toxic secondary compounds. Microcystis is a common bloom forming cyanobacteria that is capable of creating harmful algal blooms (HABs) through the production of the hepatotoxin, microcystin. HABs can cause many negative effects to the surrounding environment that include scums on surface waters, hypoxia, or unsafe drinking water. The goal of my project is to develop quantitative polymerase chain reaction (qPCR) methods that allow for early detection and quantification of toxic and non-toxic Microcystis strains to aid in the management of water resources. Water samples were collected from Bear and Muskegon Lakes biweekly between July and September 2017. The samples collected during the summer indicate a much higher proportion of non-toxic to toxic cells in both lakes, which is in accordance with similar findings in the literature. DNA copy numbers of the toxin producing gene were found to be correlated with concentrations of microcystin present in the water column. The development of these qPCR methods will serve as a tool for lake managers to make informed decisions regarding public and environmental health.

Andrew Pyman (Primary Presenter/Author), Grand Valley State University, pymana@mail.gvsu.edu;


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5/20/2019  |   11:15 - 11:30   |  254 B

NUTRIENT RATIO EFFECTS ON PHYTOPLANKTON ASSEMBLAGES IN A POTABLE SOURCE-WATER RESERVOIR OF THE SOUTHEASTERN U.S. Many potable waters in the U.S. are sustaining cultural eutrophication, concomitant with major shifts in nutrient ratios. Falls Lake is a representative, eutrophic potable source-water reservoir characterized by a degraded upper region prone to algal blooms relative to the lower region. We conducted in situ summer experiments to assess phytoplankton assemblage response to inorganic N:P ratios (molar, 16:1 and 50:1) at ambient P with N added as ammonium or nitrate, and at N:P 16:1 with both inorganic N and P enriched. In the upper region, chlorophyll a significantly increased under all three conditions (16:1 using nitrate; 50:1 using nitrate or ammonium; and 16:1 with both N and P enriched, using nitrate or ammonium). In the lower region, chlorophyll a significantly increased under the 16:1 ratio with both N and P enriched, using nitrate or ammonium. The natural assemblage in the upper region was dominated by toxigenic cyanobacteria regardless of the N-enriched form, whereas in the lower region nitrate additions favored chlorophytes and ammonium additions favored toxigenic cyanobacteria. The data suggest that co-managed, balanced reductions of N and P are needed to minimize harmful algae in this important potable-source water.

JoAnn Burkholder (Co-Presenter/Co-Author), North Carolina State University, jburk@ncsu.edu;


Nicole Lindor (Primary Presenter/Author), North Carolina State University, nllindor@ncsu.edu;


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5/20/2019  |   11:30 - 11:45   |  254 B

QUANTIFICATION OF MICROCYSTIS IN MUSKEGON AND BEAR LAKES TO EVALUATE THE RELATIONSHIP BETWEEN ABUNDANCE, TOXICITY, AND ENVIRONMENTAL CONDITIONS Cyanobacterial blooms are becoming a greater concern in freshwater systems due to their increasing frequency and potential to produce toxic secondary compounds. Microcystis is a common bloom forming cyanobacteria that is capable of creating harmful algal blooms (HABs) through the production of the hepatotoxin, microcystin. HABs can cause many negative effects to the surrounding environment that include scums on surface waters, hypoxia, or unsafe drinking water. The goal of my project is to develop quantitative polymerase chain reaction (qPCR) methods that allow for early detection and quantification of toxic and non-toxic Microcystis strains to aid in the management of water resources. Water samples were collected from Bear and Muskegon Lakes biweekly between July and September 2017. The samples collected during the summer indicate a much higher proportion of non-toxic to toxic cells in both lakes, which is in accordance with similar findings in the literature. We are continuing to explore the relationships among our data and environmental parameters, including: temperature, nutrients, and microcystin concentrations. The development of these qPCR methods will serve as a tool for lake managers to make informed decisions regarding public and environmental health.

Charlyn Partridge (Co-Presenter/Co-Author), Grand Valley State University, partridc@gvsu.edu;


Andrew Pyman (Primary Presenter/Author), Grand Valley State University, pymana@mail.gvsu.edu;


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5/20/2019  |   11:45 - 12:00   |  254 B

HYPOLIMNETIC TAILWATERS AS REFUGES FOR NUISANCE AND INVASIVE SPECIES: A CASE STUDY OF DIDYMOSPHENIA GEMINATA EFFECTS ON AQUATIC MACROINVERTEBRATES Didymosphenia geminata, a diatom that has been introduced to, and proliferated within, low temperature tailwater stream systems worldwide, alters benthic habitat and community structure. Associations between macroinvertebrate communities and D. geminata biomass in riffle and run mesohabitats were investigated at three tailwater sites and one non-tailwater control site in the South Holston River, Tennessee, USA. Didymosphenia geminata biomass was significantly higher in run mesohabitats compared to riffle mesohabitats. Macroinvertebrate diversity was correlated with flow rate, temperature, specific conductance, turbidity, and D. geminata biomass. The relative abundance of most benthic taxa and D. geminata differed significantly among riffle and run mesohabitats. Ephemeropterans, plecopterans, trichopterans, amphipods and coleopterans were more abundant in riffle mesohabitats than in run mesohabitats, whereas oligochaetes, turbellarians, isopods, and chironomids dominated run mesohabitats with high D. geminata biomass. Both D. geminata and macroinvertebrates responded similarly to flow rate, DO, specific conductance, and turbidity habitat parameters in tailwater reaches. Our research suggests that tailwater management practices should consider combining increased frequencies of high discharge pulses to dislodge D. geminata mats with low-discharge pulses to increase water temperatures. These management practices may prove effective at reducing algal standing crop.

Shea Tuberty (Co-Presenter/Co-Author), Appalachian State University, tubertysr@appstate.edu ;


Peter Blum (Co-Presenter/Co-Author), The University of North Carolina at Greensboro, pwblum@uncg.edu;


Stephanie Sellers (Co-Presenter/Co-Author), Appalachian State University, sellerssc@appstate.edu ;


Michael Gangloff (Co-Presenter/Co-Author), Appalachian State University, gangloffmm@appstate.edu ;


Luke Jacobus (Co-Presenter/Co-Author), Indiana University-Purdue University Columbus, lmjacobu@iupuc.edu;


Matthew Green (Primary Presenter/Author), Clemson University , mwgreen@g.clemson.edu;


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5/20/2019  |   12:00 - 12:15   |  254 B

THIAMINE INFLUENCES THE GROWTH OF ALGAE IN STREAMS The influence of thiamine on the growth of marine phytoplankton has been studied for decades, while we know little about its impact on freshwater systems. A nutrient amendment experiment conducted in Adirondack streams for the first time found thiamine limitation to the growth of primary producers in freshwaters. Thiamine and nitrogen promoted the growth of Chlorophyta, one of the main taxonomic groups in the study stream periphyton. The percentage of Chlorophyta in terms of cell numbers was as high as 46.9%, and 45.4% when thiamine or nitrogen was provided, respectively, compared to 26.9% on the nutrient diffusing substrates without added nutrients. Scenedesmus was one of the main genera of periphyton found in this Adirondack stream; the cell density of Scenedesmus in in situ treatments with added thiamine or nitrogen reached 6.1, and 14.1 times that of the control treatment, respectively. In a laboratory incubation study with Scenedesmus obliquus, one common species of Scenedesmus, thiamine promoted growth by enhancing the efficiency of its nitrogen utilization. By contrast, thiamine did not promote growth when very low or zero nitrogen was provided in these lab experiments.

Binbin Wang (POC,Primary Presenter), Cornell University, bw424@cornell.edu;


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