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SFS Annual Meeting

Monday, May 20, 2019
09:00 - 10:30

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09:00 - 09:15: / 254 B SPATIAL VARIATIONS IN THE BENTHIC DIATOM FLORA AND ITS DIVERSITY IN THE HIGHLAND-PLATEAU RIVERS (CENTRAL INDIA)

5/20/2019  |   09:00 - 09:15   |  254 B

SPATIAL VARIATIONS IN THE BENTHIC DIATOM FLORA AND ITS DIVERSITY IN THE HIGHLAND-PLATEAU RIVERS (CENTRAL INDIA) Diatoms constitute over 80% of the primary producers in the highland stream and river ecosystems. The study area is a north-eastern part of the Central Highlands ecoregion located to north of the tropic of Cancer between Narmada in the south and Gangetic Plains in the north. Their floras consist of total 276 taxa, 206 and 212 taxa in Ken and Tons, respectively and are quite similar (Sorensen Similarity Cs 0.67). Flora is highly similar within each river (Cs 0.65- 0.9) but varies among their corresponding sections (upper to mouth) as Cs is low (0.44 - 0.52). A general longitudinal decline in the species richness and diversity is hence evident in these rivers attributed to reduction in substrate size and its heterogeneity from source to mouth. This study examines spatial distribution of diatom communities from the rivers Ken and Tons in Central India. Studies will be useful to understand the regional patterns of diatom diversity and formulate reference conditions in these and other rivers of this region. Aim of this study to examine the spatial distribution of diatom communities and species diversity in the highland - plateau rivers Ken and Tons.

Jyoti Verma (POC,Primary Presenter), , diatombuster@gmail.com;


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09:15 - 09:30: / 254 B IDENTIFICATION OF THE NEUROTOXIN BETA-METHYLAMINO-L-ALANINE (BMAA) IN AUSTRALIAN FRESHWATER DIATOMS.

5/20/2019  |   09:15 - 09:30   |  254 B

IDENTIFICATION OF THE NEUROTOXIN BETA-METHYLAMINO-L-ALANINE (BMAA) IN AUSTRALIAN FRESHWATER DIATOMS. The amino acid beta-methylamino-L-alanine (BMAA) has been linked to numerous neurogenerative diseases, including amyotrophic lateral sclerosis (ALS) in parts of the USA. BMAA is found globally and bioaccumulates in invertebrate and vertebrate organisms. BMAA is produced by some species of cyanobacteria, marine diatoms and marine dinoflagellates. However, to date, BMAA production has not been observed in freshwater diatoms. This study aimed to determine whether freshwater diatoms produce BMAA, which could potentially pose a major threat to freshwater ecosystems, recreational water and drinking water supplies, particularly as diatom blooms regularly go unmonitored and unmanaged. Five freshwater diatom species were isolated from five locations in New South Wales, Australia and axenic cultures were established. Amino acids were extracted from the diatom cultures and analysed using liquid chromatography-tandem mass spectrometry. The production of BMAA by freshwater diatoms isolated from eastern Australian freshwater systems was confirmed, indicating a wider distribution of BMAA than previously thought.

Jordan Facey (Primary Presenter/Author), University of Technology Sydney, Jordan.A.Facey@student.uts.edu.au;


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09:30 - 09:45: / 254 B PATTERNS AND IMPLICATIONS OF MOTILITY IN EUNOTIA EHR., A DIATOM GENUS WITH A REDUCED RAPHE SYSTEM

5/20/2019  |   09:30 - 09:45   |  254 B

PATTERNS AND IMPLICATIONS OF MOTILITY IN EUNOTIA EHR., A DIATOM GENUS WITH A REDUCED RAPHE SYSTEM Motility in diatoms, largely centered on motile diatoms with complex raphe systems, remains understudied for diatoms with reduced raphe systems like in the genus Eunotia. Examination of motility in this weakly or slightly motile genus may provide unique insight into motility in diatoms overall, especially for raphid diatoms. Coverage of historical and current accounts of motility in a handful of Eunotia species reveal a variety of movement types that allow cells to move forward, pivot, and reorient to ventral-girdle view where raphe ends can connect with the substratum. Variations in overall valve morphology, especially with respect to raphe characteristics and the presence of rimoportulae, likely drive patterns of movement in this genus. The ability to move and to carry out different types of movements may influence resource interactions and habitat preferences. Consideration of motility in Eunotia in the context of diatom evolution reinforces the need for the inclusion of eunotioid taxa in studies on diatom motility. I pose directions for future study to increase knowledge around motility in Eunotia to help flesh out understanding around motility in diatoms as a whole.

Paula Furey (Primary Presenter/Author), St. Catherine University, pcfurey@stkate.edu;


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09:45 - 10:00: / 254 B FACTORS INFLUENCING POLYPHOSPHATE STORAGE IN STREAM BIOFILMS ACROSS A PHOSPHORUS GRADIENT

5/20/2019  |   09:45 - 10:00   |  254 B

FACTORS INFLUENCING POLYPHOSPHATE STORAGE IN STREAM BIOFILMS ACROSS A PHOSPHORUS GRADIENT Polyphosphate plays a myriad of physiological roles in organisms spanning every domain of life. Although likely important, we are just beginning to understand the role these phosphate chains play in the biogeochemistry of aquatic systems. The purpose of this study was to examine the polyphosphate content of stream biofilms in 20 streams sampled at base-flow throughout central Pennsylvania. These streams represented a gradient of potential phosphorus impact, driven by varying agricultural intensity in watersheds upstream of sample sites. We found that polyphosphate content as a proportion of total phosphorus content of the biofilm was positively related to algal biomass and negatively related to water column soluble reactive phosphorus (SRP). This relationship seems to be influenced mainly by the presence of Cladophora sp. in streams with low base-flow SRP. It is likely that the presence of polyphosphate in these high biomass assemblages might indicate a stress response to low phosphorus and possibly indicate a strategy for maximizing future uptake and storage of phosphorus delivered in storm runoff.

Steven Rier (Primary Presenter/Author), Bloomsburg University, srier@bloomu.edu;


Aaron Gordon-Weaver (Co-Presenter/Co-Author), Bloomsburg University, amg43366@huskies.bloomu.edu;


Jennifer Soohy (Co-Presenter/Co-Author), Bloomsburg University, jat18435@huskies.bloomu.edu;


Emily Ashberry (Co-Presenter/Co-Author), Bloomsburg University, ela77590@huskies.bloomu.edu;


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10:00 - 10:15: / 254 B COMPOSITION OF ALGAL ASSEMBLAGES DIFFERS WITH THE TEMPORAL PATTERN OF PHOSPHORUS LOADING

5/20/2019  |   10:00 - 10:15   |  254 B

COMPOSITION OF ALGAL ASSEMBLAGES DIFFERS WITH THE TEMPORAL PATTERN OF PHOSPHORUS LOADING Ecological theory suggests resource availability regulates community composition. In streams, nutrients are a limiting resource for algal assemblages. Nutrient loading to streams, however, varies temporally with the input of continuous or episodic loads from point and non-point sources, respectively. Nutrient loading pattern can thus alter the temporal availability of nutrients to stream algal assemblages. To assess how phosphorus loading pattern structures taxonomic composition and biomass of algal assemblages, we conducted a 29-day phosphorus enrichment experiment in nine stream mesocosms randomly assigned to three treatments: (1) a continuous, high phosphorus load (~5.9 g) delivered evenly (press); (2) an episodic, high phosphorus load (~5.9 g) with ~85% delivered in two 48-hour events (pulse) and; (3) a continuous, low phosphorus load (~1.2 g) representing background phosphorus concentrations (control). Phosphorus enrichment increased biomass accrual, but peak biomass did not differ between press and pulse treatments. Composition of algal classes were also similar between enriched assemblages yet differed in comparison to the control. However, diatom species composition differed among all treatments. Our results demonstrate equivalent potential for algal assemblages to accrue biomass from continuous and episodic phosphorus loads, but assemblage composition diverges with loading pattern.

Nolan J.T. Pearce (Primary Presenter/Author), Western University & Canadian Rivers Institute, npearce7@uwo.ca;


Kathryn E. Thomas (Co-Presenter/Co-Author), Environment and Climate Change Canada, katie.thomas@canada.ca;


Isabelle Lavoie (Co-Presenter/Co-Author), Institut National de la Recherche Scientique (INRS-ETE), isabelle.lavoie@ete.inrs.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;


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