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

SALMON CARRION DECOMPOSITION INFLUENCES HEADWATER STREAM COMMUNITIES OVER TIME Salmon carrion serves as a significant input of organic matter into headwater streams with lasting effects on the watershed. Our objective in this study was to determine the effect of salmon carrion introduction on aquatic macroinvertebrate and microbial communities over time. Chinook and Coho salmon carcasses were introduced to Hunt Creek, Michigan, downstream of a migration barrier. Upstream of that barrier served as a control reach, where salmon carrion was not present. Macroinvertebrates, benthic epilithic biofilms and water column microbial communities were sampled before (September) and during (October) carcass introduction along both reaches. Initial results indicate overall macroinvertebrate diversity was similar between control and salmon sites (Simpson’s Index, genus = 0.12) both before and during carcass introduction. However, the abundance of the mayfly, Acerpenna, a common collector-gatherer, was significantly higher before carcass introduction at the control sites (ANOVA, F=6.9057, p<0.05). Epilithic biofilm communities were variable over time, with trending differences between control and carcass addition reaches. Our results provide some of the first information documenting salmon carcass biotic effects in Michigan headwater streams.

Courtney Larson (Primary Presenter/Author), U.S. Environmental Protection Agency, larson.courtney@epa.gov;
U.S. EPA

Courtney Weatherbee (Co-Presenter/Co-Author), Michigan State University, weath108@msu.edu;


Jennifer L. Pechal (Co-Presenter/Co-Author), Michigan State University, pechalje@msu.edu;


Brandon Gerig (Co-Presenter/Co-Author), Northern Michigan University, bgerig@nmu.edu;


Gary Lamberti (Co-Presenter/Co-Author), University of Notre Dame, lamberti.1@nd.edu;


M. Eric Benbow (Co-Presenter/Co-Author), Michigan State University, benbow@msu.edu;

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

THE LEGACY OF LOGJAM LOSS ON BENTHIC MACROINVERTEBRATE BIOMASS AND INSECT EMERGENCE IN MOUNTAIN STREAMS Historically, the physical templates of western mountain streams were shaped by channel-spanning logjams, which increased sediment retention and created multi-thread streams channels. Today, the legacy effects of timber harvesting has reduced both wood input rates and logjam density in these streams. Here we examined mountain streams flowing through watersheds with various forest stand ages (100 to >350 years old) to determine how these systems function under both disturbed (e.g., low logjam density) and undisturbed (e.g., high logjam density) conditions. Preliminary results show that organic matter storage is ~3x higher in streams with logjams. However, benthic macroinvertebrate community biomass did not differ among streams and rates of aquatic insect emergence were lowest at sites with logjams. Trout population size was positively correlated with logjam density, suggesting that the lack of response within the benthic community was likely caused by higher trout consumption rates. Thus, while logjam strongly influence the geomorphology of mountain stream ecosystems, the primary mechanism through which they influence aquatic community structure and function is by modifying predator-prey dynamics.

Michael Venarsky (Primary Presenter/Author), Australian Rivers Institute, Griffith University, mvenarsky@gmail.com;


David Walters (Co-Presenter/Co-Author), United States Geological Survey, waltersd@usgs.gov;
Dr. David Walters is a Supervisory Research Ecologist at the Columbia Environmental Research Center. David has been a research ecologist with the USGS since 2008. Prior to that, he was an ecologist for the U.S. EPA, National Exposure Research Laboratory for 6 years. He is a freshwater ecologist with broad training in stream ecology, human impacts on aquatic ecosystems, and ecotoxicology. His current research topics include food webs and contaminant flux, aquatic-riparian linkages, stream fish ecology, land use and climate change, and invasive species.

Adam Herdrich (Co-Presenter/Co-Author), Colorado State University, adam.herdrich@gmail.com ;


Dana Winkelman (Co-Presenter/Co-Author), Colorado State University, dana.winkelman@colostate.edu ;


Bridget Livers (Co-Presenter/Co-Author), Colorado State University, bridgetlivers@gmail.com ;


Ellen Wohl (Co-Presenter/Co-Author), Colorado State University, ellenw@warnercnr.colostate.edu ;


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


Geoffrey Poole (Co-Presenter/Co-Author), Montana State University, Montana Institute on Ecosystems, gpoole@montana.edu ;

5/19/2015  |   14:00 - 14:15   |  103DE

EFFECTS OF A POLLUTED RESERVOIR ON THE DISTRIBUTION OF THE BENTHIC AND INTERSTITIAL CRUSTACEAN COMMUNITY (NORD-WEST ALGERIA) Nord-africain aquatic ecosystems, are heavily altered and exhibit a disproportional loss of invertebrate. This study aimed to identify the response of the micro-crustacean assemblages to impacts, caused by industrial contamination, and reservoir management on downstream hydrosystems. This was done by surveying the patterns of crustacean's distribution in a 300 m stretch of the middle part of the Tafna River, downstream from the dam of the Hammam Boughrara Reservoir, during natural high water, low water and reservoir water releases. Seven piezometers were sampling monthly during two years. Crustacean species were different between surface and hyporheic zone. The following species were found only in the hyporheic zone: Harpacticoidae, Pseudocandona pratensis and the stygobites species, Typhlocirolana sp, Microcharon sp., Gammaridae and Bathynellidae. These taxa were high sensitive to the hydrological modifications. A significant decrease in density of Acanthocyclops, Harpacticoides, Typhlocirolana sp. and Microcharon sp., and disappearance of some taxa were observed downstream of the dam during reservoir water releases. These results could be linked to the combination of current velocity, vertical hydraulic gradient, grain sizes, dissolved oxygen and biochemical oxygen demand.

Nouria Belaidi (Primary Presenter/Author), University of Tlemcen (ALGERIA), n_belaidi@mail.univ-tlemcen.dz;


Amina Taleb (Co-Presenter/Co-Author), University of Tlemcen (ALGERIA), taleb_14@hotmail.com;

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

EFFECTS OF ANTHROPOGENIC DISTURBANCES ON AQUATIC MACROINVERTEBRATES - DEPOSITION AND THERMAL REGIMES, OR THE IMPORTANCE OF APPROPRIATE SITES SELECTION Aquatic ecosystems are exposed to many anthropogenic pressures. One of them is the construction of dams that control the water level and sometime lead to winter drawdown. These dams are important to reduce spring flooding and produce hydropower but they also cause annual water level variations ranging from <1m to >15m. These variations can affect littoral macroinvertebrates communities via desiccation, freezing and habitat loss. It was shown that drawdown affects, positively or negatively, macroinvertebrates abundance and biodiversity, but there is no clear consensus. This lack in consensus is most likely the result of small sampling size and/or no habitat subsampling. Knowing that the abundance and community composition is influenced by the environment in the context of natural water level variations (<1m), it will be shown that the deposition and thermal environments, where you sample macroinvertebrates, also influence the abundance and the composition of the macroinvertebrates found in your sample in the context of anthropogenic disturbance (i.e. drawdown). Theses results will enable the optimization of sites selection and thus a better understanding of the impacts of anthropogenic disturbances on macroinvertebrates communities.

Gabrielle Trottier (Primary Presenter/Author), McGill University, gabrielle.trottier@mail.mcgill.ca;


Katrine Turgeon (Co-Presenter/Co-Author), McGill University, katrine.turgeon@mail.mcgill.ca;


Christian Nozais (Co-Presenter/Co-Author), Université du Québec à Rimouski, christian_nozais@uqar.ca;


Chris Solomon (Co-Presenter/Co-Author), Cary Institute of Ecosystem Studies, solomonc@caryinstitute.org;


Irene Gregory-Eaves (Co-Presenter/Co-Author), McGill University, irene.gregory-eaves@mcgill.ca;

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

RECOVERY OF AQUATIC MACROINVERTEBRATE ASSEMBLAGES FOLLOWING STREAM DRYING IN SOUTHWEST GEORGIA, USA Demand for agricultural irrigation water during recent droughts has been associated with an increase in the number of intermittent stream miles in the lower Flint River drainage basin in southwest Georgia. We sampled macroinvertebrate assemblages over 9 months in intermittent stream reaches that either remained wet (RW) or temporarily dried (DR) during this period. Prior to flow cessation, taxa and EPT richness were similar between reach types while EPT abundance was higher in DR reaches, which were closer to a perennial source. Desiccation-resistant taxa and flying adults contributed to a rapid rebound in taxa richness in DR reaches within two weeks of flow resumption, while EPT richness recovered gradually over the 5-month period. Recovery patterns for total abundance were similar while EPT abundance did not fully recover during the sampling period. EPT and taxa richness did not vary across time in RW reaches while abundance declined from September-December and increased to a peak in May. These results indicate that an extended recolonization period is required to recover sensitive (EPT) macroinvertebrate assemblages lost during periods of channel drying.

Chelsea R. Smith (Primary Presenter/Author), The University of Alabama, crsmith5@crimson.ua.edu;


Paul V. McCormick (Co-Presenter/Co-Author), J.W. Jones Ecological Research Center, pmccormick@jonesctr.org;


Alan Covich (Co-Presenter/Co-Author), Odum School of Ecology, University of Georgia, a.covich@gmail.com;


Stephen Golladay (Co-Presenter/Co-Author), Georgia Water Planning and Policy Center at ASU, steve.golladay@jonesctr.org;

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

CYCLES OF BOOM AND BUST IN COASTAL CALIFORNIA INTERMITTENT STREAMS Intermittent streams in California experience dramatic cycles of boom and bust across seasons and years. In wet winters these streams have many kilometers of flowing water, whereas in dry seasons or years only small, isolated pools remain. The communities inhabiting these remnant pools are rarely studied and their role in facilitating community recovery in adjacent reaches is unknown. We quantified community composition in remnant pools at one small and one large intermittent coastal stream in California: John West Fork (3km2) and Coyote Creek (240km2). After flow returned, we monitored community development in intermittent reaches adjacent to perennial pools. Both streams supported >150 invertebrate species in remnant pools. Coho salmon and steelhead inhabited pools at John West Fork, and 11 species of native fish and amphibians inhabited pools in Coyote Creek. Early in the wet season, communities in newly-flowing intermittent reaches were dominated by taxa with life stages resistant to drought (e.g. diapause). However, within several months taxa from perennial pools had moved into adjacent intermittent reaches. Our results demonstrate the importance of perennial refuges in maintaining biodiversity in intermittent streams.

Michael Bogan (Primary Presenter/Author), University of California, Berkeley, mbogan@berkeley.edu;


Robert Leidy (Co-Presenter/Co-Author), Environmental Protection Agency, San Francisco, Leidy.Robert@epa.gov;


Stephanie Carlson (Co-Presenter/Co-Author), Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, U.S., smcarlson@berkeley.edu;