6/07/2017  |   09:00 - 09:15   |  302B

NEW INSIGHTS TO STREAM METABOLISM IN THE ERA OF FOOD PROCUTION: A GLOBAL META-ANALYSIS. Global agriculture has widely altered stream ecosystem processes. At the base of the food web agriculture modifies the rates of gross primary production and ecosystem respiration (i.e. stream metabolism), and can lead to changes in carbon sources fueling ecosystem function. Previous synthesis of anthropogenic influences on metabolism have studied the aggregated effects of diverse land uses (e.g. urban, logging and agriculture) despite that metabolic responses may differ between land use types. Recent metabolism studies including previously underrepresented biomes provide a timely opportunity to deepen our understanding of global patterns of metabolism in reference and agricultural streams. The overarching goal of this meta-analysis was to provide a global view of how agriculture has altered metabolism across biomes. Specifically, we set out to answer the following questions: Do streams in biomes with contrasting riparian vegetation types respond differently to agriculture? How does metabolism differ between food production systems? We discuss the implications of the light regime as a main driver of global stream metabolism, the implications of food production on metabolism and address future research needs.

Aline Ortega Pieck (Primary Presenter/Author), University of Idaho, alineorteg@gmail.com;


Alexander Fremier ( Co-Presenter/Co-Author), Washington State University, Pullman, WA, alex.fremier@wsu.edu;


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6/07/2017  |   09:15 - 09:30   |  302B

GEOMORPHOLOGIC DRIVERS OF MACROINVERTEBRATE COMMUNITY STRUCTURE AND PRODUCTION IN TWO CONTRASTING LARGE RIVERSCAPES Understanding the interaction between geomorphology and ecosystem processes is a central theme in ecology. Although there is a rich history of linking variation in habitat features to biota in small streams, these connections are poorly understood in large riverscapes. Recent studies suggest that both in-channel and external habitat-forming processes are important in large rivers. However, research is needed to (a) understand how these processes differentially generate patterns of benthic habitat, and (b) scale to influence macroinvertebrate productivity. We combined benthic habitat maps, aerial photography, and benthic sampling to explore linkages between geomorphology and secondary production at multiple scales in the Missouri (regulated) and Yellowstone (largely free-flowing) rivers in Montana, USA. We found that interactions between the river and surrounding landforms generate a mosaic of stable habitat patches that positively influence macroinvertebrate diversity and production. Further, impoundment led to a reduction in downstream off-channel habitats and larger sediment size through channel degradation, resulting in a highly productive, species-poor community. Elucidating connections between geomorphology and ecological processes will help predict how habitat alteration will influence productivity in large rivers.

Eric Scholl (Primary Presenter/Author), U.S. Geological Survey, escholl@usgs.gov;


Wyatt Cross ( Co-Presenter/Co-Author), Montana State University, wyatt.cross@montana.edu ;


Addie Dutton ( Co-Presenter/Co-Author), Montana Cooperative Fishery Research Unit, Montana State University , adeline.dutton@msu.montana.edu;


Christopher Guy ( Co-Presenter/Co-Author), U.S. Geological Survey, Montana Cooperative Fishery Research Unit, Montana State University, cguy@montana.edu;


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6/07/2017  |   09:30 - 09:45   |  302B

Phosphorus Releases From Glen Canyon Dam Control Riverine Primary Production and Higher Trophic Levels Up To 120 Km Downstream Dams can dramatically alter the transport of nutrients through river networks and can also disrupt downstream community structure. Still, the linkages between dam-induced changes in water chemistry and riverine food webs are not well understood. Here, we use high frequency dissolved oxygen measurements in combination with an inverse modeling approach to estimate daily rates of gross primary production for five years in the Colorado River at a site 120 kilometers downstream of Glen Canyon Dam. We compared these rates to monthly nutrient concentrations at the outflow to Lake Powell and to quarterly measurements of macroinvertebrate biomass and native fish condition in the Colorado River. Soluble reactive phosphorus concentrations at the dam outflow were positively related with early spring (February-April) and pre monsoon (May-July) primary production across five years. Seasonal primary production was also positively related to invertebrate drift biomass and the condition of native fish. We hypothesize that phosphorus limitation below Glen Canyon dam lowers production at the base of the food web with consequences for higher trophic levels.

Bridget Deemer (Primary Presenter/Author), U.S. Geological Survey, Southwest Biological Science Center, bdeemer@usgs.gov;


Charles Yackulic ( Co-Presenter/Co-Author), USGS Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, cyackulic@usgs.gov;


Robert O. Hall ( Co-Presenter/Co-Author), Flathead Lake Biological Station, University of Montana, bob.hall@flbs.umt.edu;


Ted Kennedy ( Co-Presenter/Co-Author), USGS Southwest Biological Science Center, Grand Canyon Monitoring and Research Center, tkennedy@usgs.gov;


Jeffrey Muehlbauer ( Co-Presenter/Co-Author), University of Alaska Fairbanks, USGS Alaska Cooperative Fish and Wildlife Research Unit, jdmuehlbauer@alaska.edu;


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6/07/2017  |   09:45 - 10:00   |  302B

ESTIMATION OF ECOSYSTEM METABOLISMS BY OPEN DIEL OXYGEN METHOD IN THE MIMI RIVER, JAPAN Quantitative estimation of ecosystem metabolism is significant to understand their functions and suggest sustainable plans for management of ecosystem services. Aquatic ecosystem metabolism can be estimated by monitoring the diel change in dissolved oxygen concentrations. We have been monitoring of water quality items of water temperature, dissolved oxygen, pH, electric conductivity, and turbidity for several years in the large river Mimi River in Kyushu, Japan. We are able to use the discharge data from outlet flow of upstream dam. The mean annual discharge of Mimi River is approximately 45 m3 s-1.There are two main events of heavy precipitation by seasonal rain front and typhoons in Japan of Asian monsoon zone. High discharges of Mimi River were recorded to be more than 1000 m3 s-1 during floods. We investigated accuracy and uncertainty of river metabolism estimations, especially during floods and immediately after floods and tried to evaluate impacts of flood disturbance on river metabolism. We also showed seasonal changes in river metabolism and discussed environmental factors for changes in river metabolism.

Ryosuke Yamamoto (Primary Presenter/Author), Central Research Institute of Electric Power Industry, r-yama@criepi.denken.or.jp;


Daisuke Nakano ( Co-Presenter/Co-Author), Central Research Institute of Electric Power Industry, d-nakano@criepi.denken.or.jp;


Masahiro Imamura ( Co-Presenter/Co-Author), Central Research Institute of Electric Power Industry, mima@criepi.denken.or.jp;


Ryosuke Yamamoto ( Co-Presenter/Co-Author), Central Research Institute of Electric Power Industry, r-yama@criepi.denken.or.jp;


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6/07/2017  |   10:00 - 10:15   |  302B

A LITTLE BIT OF ALGAE GOES A LONG WAY: NUTRIENT ENRICHMENT STIMULATES ALGAL GROWTH IN HEAVILY SHADED STREAMS Algae are often limited by nitrogen (N) and/or phosphorus (P) but the strength of nutrient limitation is thought to vary with light availability. Here, we tested responses of algae to experimental N and P enrichment in five heavily shaded (light-limited) streams that were enriched along dual gradients of high to low P and low to high N concentrations. Mean annual biofilm chlorophyll-a increased during enrichment (6x-17x, e.g., from 1 mg/m2 to 20 mg/m2), whereas mean annual biofilm biomass only increased up to 1.8x. During high-light periods in spring, chlorophyll-a increased up to 33x and biomass up to 3.3x compared to pre-enriched conditions. Biomass and chlorophyll-a responded more to N than to P enrichment. Although responses of algae were temporally limited, high-magnitude, short-term biofilm production was positively correlated with biomass of diatom-consuming macroinvertebrates (R2 = 0.20), likely via increased proportions of diatoms consumed. Moreover, we found an increased importance of diatom-consumers in salamander diets. Our study suggests that nutrient enrichment can lead to seasonal pulses of biofilm production, with measurable effects at higher trophic levels, even in naturally light-limited, detritus-based ecosystems.

Phillip Bumpers (Primary Presenter/Author), University of Georgia, bumpersp@gmail.com;


Amy Rosemond ( Co-Presenter/Co-Author), University of Georgia, rosemond@uga.edu;


Jonathan P. Benstead ( Co-Presenter/Co-Author), The University of Alabama, jbenstead@ua.edu;


Lee Demi ( Co-Presenter/Co-Author), North Carolina State University, mickdemi@yahoo.com;


John S. Kominoski ( Co-Presenter/Co-Author), Florida International University, jkominoski@gmail.com;


John C. Maerz ( Co-Presenter/Co-Author), University of Georgia, jcmaerz@uga.edu;


David W. P. Manning ( Co-Presenter/Co-Author), The Ohio State University, manning.413@osu.edu;


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