5/19/2015  |   13:30 - 13:45   |  103AB

EFFECTS OF CONTAMINANTS ON STREAM BIOFILMS: AMPHETAMINE, ANTIHISTAMINE, AND SALT Urban streams receiving wastewater contain contaminants including illicit drugs, pharmaceuticals, and road salt. Contaminants may have complex, sublethal consequences on ecosystem structure and function. We focused on the effects of amphetamine, antihistamine (the active ingredient in Benadryl), and road salt on the algal and bacterial communities in stream biofilms. We used artificial stream experiments, as well as contaminant exposure substrates (CES) deployed in two urban and one suburban stream locations in Baltimore, Maryland. In artificial streams, all three contaminants suppressed gross primary production (GPP) of biofilms after 3 weeks of chronic exposure. Only salt significantly suppressed community respiration (CR). In Baltimore, biofilms on CES amended with antihistamine, salt, or a mix of both also showed suppressed GPP, except for CES with antihistamine in the most urban stream location, after two weeks. None of the contaminants suppressed CR, suggesting these bacterial communities are tolerant, especially in the most urban site. To understand the mechanisms underlying changes in metabolism, we examined composition of biofilm communities exposed to contaminants using microscopic identification of algae and high-throughput sequencing of bacterial and algal genes.

Sylvia Lee (Primary Presenter/Author), U.S. Environmental Protection Agency, lee.sylvia@epa.gov;


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


Alexis Paspalof (Co-Presenter/Co-Author), University of Nebraska Lincoln, apaspalof@huskers.unl.edu;


John Kelly (Co-Presenter/Co-Author), Loyola University Chicago, Jkelly7@luc.edu;


Sujay Kaushal (Co-Presenter/Co-Author), University of Maryland, skaushal@umd.edu;
Dr. Sujay Kaushal is currently a Professor in the Department of Geology & Earth System Science Center at the University of Maryland, College Park, and he has been in this position since 2010. Prior to that, Dr. Kaushal was an assistant professor at the University of Maryland Center for Environmental Science from 2005-2010. His research expertise deals with: investigating causes and consequences of freshwater salinization, understanding the impacts of stormwater management and stream restoration on water quality, elucidating fate and transport of urban pollutants; and tracking sources of nonpoint pollution using geochemical approaches and tracers. Dr. Kaushal has authored over approximately 100 peer-reviewed papers in journals such as Proceedings of the National Academy of Sciences, Nature Reviews Earth and Environment, and Nature Sustainability, and he has received awards such as the UMD College of Computer, Mathematical, and Natural Sciences Junior Faculty Award and the IRPE Prize in limnetic ecology (https://www.int-res.com/ecology-institute/eci-prize-awarding/eci-award-ceremony-2012/). From the perspective of education and training, he was a postdoctoral fellow at the Cary Institute from 2003-2005. He received his PhD from the University of Colorado, Boulder, and he received his bachelors degree from Cornell University.

5/19/2015  |   13:45 - 14:00   |  103AB

CO-LIMITATION BY N AND P CHARACTERIZES ALGAL COMMUNITIES ACROSS LAND USE AND NUTRIENT AVAILABILITY Scientific understanding of nutrient limitation lacks predictive power and mechanistic clarity. Historically, freshwater systems were assumed to be singly limited by phosphorus (P), but a recent meta-analysis demonstrated that algal response to nutrient manipulation most frequently supports co-limitation by nitrogen (N) and P. However, the role of resource availability and the ratio of this availability on nutrient limitation of aquatic primary producer communities remains unclear. Therefore, the goal of our research was to determine how resource availability and land use influence nutrient limitation by N and P of primary production in aquatic communities across 9 lakes in Minnesota.Despite large differences in land use (agricultural, urban, and suburban), nutrient loading, and nutrient availability, algal communities’ response to nutrient manipulation was consistently characterized by a co-limitation by N and P. These results suggest that lake processes (denitrification, nitrogen fixation) likely contribute to nutrient limitation.

Anika Bratt (Primary Presenter/Author), Duke University, anikabratt@gmail.com;


Jacques Finlay (Co-Presenter/Co-Author), University of Minnesota, jfinlay@umn.edu;


Jill Welter (Co-Presenter/Co-Author), St. Catherine University, jill.welter@gmail.com;


Bree Vculek (Co-Presenter/Co-Author), St. Catherine University, bavculek@stkate.edu;


Kerrick Sarbacker (Co-Presenter/Co-Author), St. Catherine University, kesarbacker@stkate.edu ;

5/19/2015  |   14:15 - 14:30   |  103AB

USING SEASONAL DATA ON NUTRIENTS AND ALGAL BIOMASS TO INFORM THE DESIGN OF MORE EFFECTIVE AND EFFICIENT WATER QUALITY MONITORING Water quality monitoring programs face a tradeoff between spatial and temporal coverage. We use monthly data collected at 22 site in three agricultural regions of the United States to examine assumptions underlying synoptic design and to develop an more effective and efficient approach for monitoring benthic algae. Maximum benthic chlorophyll (ChlaMax) ranged from 14 to 406 mg/m2 (at-site median 118 mg/m2) and exceeded 100 mg/m2 at 13 sites. No month represented a reliable reference period for ChlaMax. Algal biomass accrued rapidly and persisted for no more than 1 to 3 months. At-site variation of monthly chlorophyll was equal to the cross-site variation in ChlaMax. A single sample of chlorophyll does not provide a reliable index of ChlaMax and there were no regionally consistent reference periods other than spring and late summer when sampling would be likely to capture high algal biomass. A single sample of DIN collected at random, however, was a useful indicator of ChlaMax. Integrating temporal information into synoptic design can lead to more effective and efficient monitoring.

Christopher Konrad (POC,Primary Presenter), US Geological Survey, cpkonrad@usgs.gov;


Mark Munn (Co-Presenter/Co-Author), U.S. Geological Survey, Tacoma, WA, mdmunn@usgs.gov;

5/19/2015  |   14:30 - 14:45   |  103AB

DIRECT AND INDIRECT EFFECT OF EUTROPHICATION ON LAKE ECOSYSTEMS: SUPPORT FOR NUTRIENT CRITERIA DEVELOPMENT Excess nutrient loading is among the most prevalent causes of water quality impairment in the United States. Nutrients affect aquatic systems most directly by increasing algal and macrophyte production and shifting algal and macrophyte species composition, and most indirectly by altering dissolved oxygen (DO) and disrupting the food web. We used a compiled long-term ecological research (LTER) dataset of 1619 lakes in the Northern Lakes and Forests ecoregion of Wisconsin to explore the effect of nutrient enrichment on biological condition of the lake community (zooplankton, invertebrate, and fish assemblages). Although the biological community, especially fish and zooplankton, responded to total nitrogen and phosphorous concentrations, their linkages with hypoxia were less clear. However, hypoxia (DO < 2 mg/L) was strongly related to Chl a concentrations despite spatial and seasonal variations of DO and lake stratification. Furthermore, elevated Chl a concentrations were strongly related to both TP (R2=0.47) and TN (R2 = 0.53), indicating enrichment predicts hypoxia in these lakes. Nutrient criteria can be established based on these direct and indirect relationships to biological communities.

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


Michael Paul (Co-Presenter/Co-Author), U.S. Environmental Protection Agency, Paul.Michael@epa.gov;


Ann Roseberry Lincoln (Co-Presenter/Co-Author), Tetra Tech, Inc., Ann.Lincoln@tetratech.com;

5/19/2015  |   14:45 - 15:00   |  103AB

ESTIMATION OF INLAND LAKE CHLOROPHYLL A BASED ON LANDSAT TM/ETM+ AND BOOSTED REGRESSION TREES (BRT) Compared to in-situ water quality measurements, remote sensing observations cover larger areas and longer periods with lower cost. Few algorithms have provided robust Chl estimation over large areas covering multiple satellite overpass paths, or/and one area for a long time period. We applied a new advanced machine learning algorithm (i.e. Boosted Regression Trees, BRT) in Chl estimation. Evaluated by 10-fold cross validation, Landsat TM/ETM+ bands and band ratios together could explain 46.1% and 37.9% of Chl variance measured, respectively, in the first National Lake Assessment (lake number = 1149) across the United States and during a 23-year program monitoring 39 reservoirs in Missouri. The BRT algorithm was slightly affected by sediments and CDOM. Most error is likely related to atmospheric effects, specular reflectance on water surface, and in-situ data that were used in BRT fitting and validation. Our work indicates remote sensing could be a valuable tool for long-term ecological assessments of inland and turbid waters.

Shengpan Lin (Primary Presenter/Author), Department of Zoology, Michigan State University, lin.shengpan@gmail.com;


Jiaguo Qi (Co-Presenter/Co-Author), Department of Geography, Michigan State University, qi@msu.edu;


John Jones (Co-Presenter/Co-Author), Department of Fisheries and Wildlife Sciences, University of Missouri, JonesJ@missouri.edu ;


Jan Stevenson (Co-Presenter/Co-Author), Michigan State University, rjstev@cns.msu.edu;

5/19/2015  |   15:00 - 15:15   |  103AB

ENVIRONMENTAL DRIVERS OF BENTHIC CYANOBACTERIAL DISTRIBUTION AND TOXIN PRODUCTION IN A RIVER NETWORK Most cyanobacterial harmful algal blooms occur in estuaries and lakes, but in the Eel River in Northern California benthic cyanobacterial mats have killed 11 dogs in the last decade. In rivers in Mediterranean climates, benthic algae fuel summer aquatic food webs. When algal assemblages tip towards toxic cyanobacteria water quality is degraded, negatively impacting food webs and public safety. During two drought summers, 2013 and 2014, we measured spatial patterns, cyanotoxin concentrations, and abiotic conditions of cyanobacterial mats in the Eel River. Species of Anabaena and Phormidium were the dominant cyanotoxin producers in the watershed. Concentrations of the neurotoxin anatoxin-a were higher than the liver toxin microcystin, and concentrations peaked during mid-summer in warm middle-reaches of the watershed. However, cyanotoxin concentrations varied weekly, suggesting rapid turnover between toxin-producing and non-producing strains. We hypothesize that low river discharge and warm water temperatures associated with droughts increase the abundance of cyanobacteria in the Eel River. Knowledge of environmental conditions that promote cyanobacteria in rivers is needed for management to maintain productive food webs and reduce public health threats from cyanotoxins.

Keith Bouma-Gregson (Primary Presenter/Author), U.S. Geological Survey, kbouma-gregson@usgs.gov;


Raphael Kudela (Co-Presenter/Co-Author), University of California, Santa Cruz, kudela@ucsc.edu;


Keith Bouma-Gregson (Co-Presenter/Co-Author), University of California, Berkeley, kbg@berkeley.edu;
Dr. Mary E. Power is Professor in the Department of Integrative Biology at the University of California, Berkeley. She was awarded an honorary doctorate by Umea University, the Kempe Medal for distinguished ecologists, and the Hutchinson Award from the American Society of Limnologists and Oceanographers. She is a member of the California Academy of Science, the American Academy of Arts and Sciences, and National Academy of Sciences, USA. She has served on the Editorial Board of PNAS (2014 to present) and Science (2006-2009). Mary also served as President of the American Society of Naturalists, and of the Ecological Society of America. Since 1988, she has been the Faculty Director of the Angelo Coast Range Reserve, (one of the UC Natural Reserve System sites, a 3500 ha reserve protected for university teaching and research). She has studied food webs in temperate and tropical rivers, as well as linkages of rivers, watersheds and near-shore environments. Focal organisms include cyanobacteria, algae, invertebrates, fish, estuarine crustaceans and terrestrial grasshoppers, spiders, lizards, birds and bats. By studying how key ecological interactions depend on landscape and temporal contexts, her group hopes to learn how river-structured ecosystems will respond to changes over space and time in climate, land use, and biota. Her group also collaborates closely with Earth and atmospheric scientists in site-based research to investigate linkages among riverine, upland, and near-shore ocean ecosystems.