Tuesday, June 6, 2017
11:00 - 12:30

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11:00 - 11:15: / 306C THE EFFECT OF WHOLE STREAM WARMING ON CHIRONOMID (DIPTERA) COMMUNITY COMPOSITION AND EMERGENCE TIME OF INDIVIDUALS

6/06/2017  |   11:00 - 11:15   |  306C

THE EFFECT OF WHOLE STREAM WARMING ON CHIRONOMID (DIPTERA) COMMUNITY COMPOSITION AND EMERGENCE TIME OF INDIVIDUALS To predict responses to stream water warming, we studied insect emergence for two summers in the upper reach of a spring-fed stream (5.8°C) and heated up lower reach (9.1°C) of the same stream. For comparison a warm stream (19-22°C) was studied simultaneously. Density and diversity of emerging insects was greater in the heated reach than the unheated reach, especially during the first summer. Some chironomid species are absent in the heated reach (Orthocladius frigidus, Chaetocladius laminatus, Diamesa aberrata), while other were only present in the heated reach (Rheocricotopus effusus, Paraphaenocladius impensus, O. fuscimanus, Micropsectra atrofasciata). Species found in both reaches had an earlier emergence and/or had more emergence periods in the heated reach (Thienemanniella sp., Eukiefferiella claripennis, E. minor, Parochlus kiefferi), than in the cold reach. Metriocnemus eurynotus was unaffected by the water heating. Warming up stream water by 3.3°C altered densities and diversity of emerging chironomids, their life histories and species composition.

Gisli Mar Gislason (Primary Presenter/Author), University of Iceland, gmg@hi.is;


Soila Inkeri Susanna Silvonen ( Co-Presenter/Co-Author), University of Iceland/University of Helsinki, sis164@hi.is;


Thora Katrin Hrafnsdottir ( Co-Presenter/Co-Author), Natural History Museum of Kopavogur, Iceland, thora@natkop.is;


Aron Dalin ( Co-Presenter/Co-Author), University of Iceland, adj11@hi.is;


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11:15 - 11:30: / 306C SEX AND SIZE SUBSIDIZED: THE EFFECTS OF PHOSPHORUS SUBSIDIES ON NYMPHAL MAYFLIES PHOSPHORUS CONTENT AND BODY SIZE

6/06/2017  |   11:15 - 11:30   |  306C

SEX AND SIZE SUBSIDIZED: THE EFFECTS OF PHOSPHORUS SUBSIDIES ON NYMPHAL MAYFLIES PHOSPHORUS CONTENT AND BODY SIZE Across a species’ ontogeny, small individuals grow faster than larger ones, and growth rate accelerates with dietary phosphorus (P) subsidies, potentially culminating in differences in P content and body size among populations. We sampled 7 central Texas streams representing a P enriched resource gradient and compared P content and body size between development classes and sexes of Baetis and Neochoroterpes mayfly nymphs. Percent P between sexes of Baetis did not differ within sites, whereas Neochoroterpes females were more P enriched than males in the largest size class, and female P enrichment increased across the P gradient. High P site Baetis were 4X as massive, and Neochoroterpes were 2X as massive as individuals from low P sites. At low P sites, Baetis mass did not differ among sexes within size classes, but Baetis females were at least 25% larger than males at high P sites. Neochoroterpes females were usually larger than males at low P sites, and at least 30% larger than males at high P sites. Body size increases have direct fitness consequences for mayflies because body size and fecundity are positively correlated.

Jeffrey A. Back (Primary Presenter/Author), Baylor University, Jeff_Back@baylor.edu;


Jason M. Taylor ( Co-Presenter/Co-Author), USDA, Agricultural Research Service, National Sedimentation Lab, jason.taylor@ars.usda.gov;


Ryan S. King ( Co-Presenter/Co-Author), Baylor University, Ryan_S_King@ Baylor.edu;


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11:30 - 11:45: / 306C COMPARING THE POPULATION DYNAMICS OF THREATENED LAHONTAN CUTTHROAT TROUT IN TWO DISPARATE NATIVE LAKES

6/06/2017  |   11:30 - 11:45   |  306C

COMPARING THE POPULATION DYNAMICS OF THREATENED LAHONTAN CUTTHROAT TROUT IN TWO DISPARATE NATIVE LAKES Eutrophic, desert terminal Summit Lake and oligotrophic, montane Independence Lake are home to the last two native, self-sustaining, lacustrine populations of threatened Lahontan cutthroat trout (Oncorhynchus clarkii henshawi, aka LCT). To aid conservation strategy by increasing knowledge of LCT population ecology across its habitat spectrum, we compared the population dynamics of these special populations. Using a novel stage-structured matrix population model that incorporates spawning transitions, we estimated the populations’ growth and net reproductive rates and performed sensitivity analyses. We parameterized the models with estimates from a population viability analysis at Independence Lake and a ‘robust design’ capture mark recapture experiment at Summit Lake. Preliminary results indicate that both populations are declining and that the juvenile stages are the most sensitive. However, unlike Independence Lake, adult non spawners that spawn the following year displayed the second highest sensitivity at Summit Lake. Although the results suggest that their dynamics are similar, conservation managers should remain vigilant to evaluate each population and its environmental context separately. For example, recent drought conditions may be the key driver affecting the spawning behavior at Summit Lake.

Teresa Campbell ( Co-Presenter/Co-Author), University of Nevada Reno, tcampbs@gmail.com;


Christopher Jerde ( Co-Presenter/Co-Author), University of Nevada Reno, Global Water Center, cjerde@ucsb.edu;


Sudeep Chandra ( Co-Presenter/Co-Author), University of Nevada Reno, Global Water Center, sudeep@unr.edu;


Zeb Hogan ( Co-Presenter/Co-Author), University of Nevada Reno, Global Water Center, zhogan@unr.edu;


William Cowan ( Co-Presenter/Co-Author), Summit Lake Paiute Tribe, william.cowan@summitlaketribe.org;


Robert Zeyer ( Co-Presenter/Co-Author), Summit Lake Paiute Tribe, robert.zeyer@summitlaketribe.org;


Jessica Saenz ( Co-Presenter/Co-Author), Summit Lake Paiute Tribe, jessica.saenz@summitlaketribe.org;


Kristin Holbert ( Co-Presenter/Co-Author), Summit Lake Paiute Tribe, kristin.holbert@summitlaketribe.org;


Nick Rzyska-Filipeck ( Co-Presenter/Co-Author), Summit Lake Paiute Tribe, nicholas.rzyska-filipek@summitlaketribe.org;


James Simmons (Primary Presenter/Author), University of Nevada Reno, jamessimmons@nevada.unr.edu;


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11:45 - 12:00: / 306C THE EFFECTS OF ONTOGENY, DENSITY, AND FLOW ON THE SPATIAL DISTRIBUTION OF LARVAL BLACK FLIES ON A SINGLE BED ELEMENT.

6/06/2017  |   11:45 - 12:00   |  306C

THE EFFECTS OF ONTOGENY, DENSITY, AND FLOW ON THE SPATIAL DISTRIBUTION OF LARVAL BLACK FLIES ON A SINGLE BED ELEMENT. Investigation into resource acquisition of organisms with complex life cycles has primarily focused on ontogenetic shifts in feeding niche, and less is known about ontogenetic changes within one life stage. One such group, the black flies (Diptera: Simuliidae) are a widely distributed group, whose benthic, suspension feeding larvae prefer high velocity microhabitats to maximize resource flux. We investigated the individual and integrated effects of ontogenetic stage (larval size), density (individuals vs. aggregations) and flow (both bulk and small spatial variations), on microhabitat optimization on a single bed element for larvae of the black fly Simulium tribulatum. All three factors significantly affected larval responses to fine-scale flow conditions. Late instar larvae were more likely to move to higher flow regions when initially attaching to the experimental bed element in lower flow areas, and both bulk flow velocity and population density modified this behavior. Neonate larvae did not similarly respond to local flow conditions. Understanding these effects will increase both our understanding of and ability to predict population-level distributions of these organisms, and similar filter-feeding macrobenthos that are important for stream ecosystems.

Christy Violin (Primary Presenter/Author), Saint Joseph’s University, Philadelphia, PA, USA, cviolin@sju.edu;


Jonathan Fingerut ( Co-Presenter/Co-Author), Saint Joseph’s University, Philadelphia, PA, USA, jfingeru@sju.edu;


James Thomson ( Co-Presenter/Co-Author), Monash University, Melbourne, Victoria, Australia, jim.thomson@delwp.vic.gov.au;


David Hart ( Co-Presenter/Co-Author), Mitchell Center for Sustainability Solutions, University of Maine, Orono, ME, USA, david.hart@umit.maine.edu;


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12:00 - 12:15: / 306C CRYPTIC LINEAGES OF THE COMMON ALPINE MAYFLY BAETIS ALPINUS SHOW STRONG LIFE HISTORY DIVERGENCE

6/06/2017  |   12:00 - 12:15   |  306C

CRYPTIC LINEAGES OF THE COMMON ALPINE MAYFLY BAETIS ALPINUS SHOW STRONG LIFE HISTORY DIVERGENCE Cryptic species challenge our understanding of species ecology and response to environmental change. If species, in fact, comprise multiple ecologically divergent lineages, any apparent wide ecological niche and strong life-history plasticity may actually reflect genetically distinct specialists. We tested for the presence of cryptic lineages in the common alpine mayfly Baetis alpinus across the Swiss Alps using mitochondrial cytochrome oxidase I gene and 10 polymorphic nuclear microsatellites markers. Genetic analyses revealed two highly differentiated cryptic lineages that occur sympatrically over broad spatial scales. One lineage appeared to be more restricted to high elevation sites. Further, we examined larval cohort structure in two glacial headwater basins in 2013 to determine whether the two lineages differ in voltinism and phenology. We found contrasting life cycles between cryptic lineages involving differential developmental pathways. An egg clutch survey within one basin consistently indicated partial temporal segregation in reproductive periods. Widespread generalist morphospecies can hide cryptic lineages with much narrower ecological niches and distribution ranges, and higher risk of extinction in the face of global change.

Marie Leys (Primary Presenter/Author), Swiss Federal Institute of Aquatic Science and Technology, EAWAG, ; Aquatic Ecology dpt., marie.leys@eawag.ch;


Irene Keller ( Co-Presenter/Co-Author), University of Bern and Swiss Institute of Bioinformatics, irene.keller@dkf.unibe.ch;


Katja Räsänen ( Co-Presenter/Co-Author), Aquatic Ecology - Eawag, katja.rasanen@eawag.ch;


Christopher Robinson ( Co-Presenter/Co-Author), Swiss Federal Institute of Aquatic Science and Technology, EAWAG ; Aquatic Ecology dpt., Christopher.robinson@eawag.ch;


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12:15 - 12:30: / 306C CONSERVATION GENOMICS OF AN ALPINE STONEFLY THREATENED BY CLIMATE CHANGE

6/06/2017  |   12:15 - 12:30   |  306C

Conservation genomics of an alpine stonefly threatened by climate change Climate warming is causing rapid loss of glaciers and snowpack in mountainous regions worldwide. These changes are predicted to negatively impact the habitats of many range-restricted species, particularly endemic, mountaintop species dependent on the unique thermal and hydrologic conditions found only in glacier and snowfed alpine streams. Zapada glacier (Order Plecoptera: Family Nemouridae) was recently petitioned for listing under the U.S. Endangered Species Act due to climate change-induced habitat loss. Zapada glacier is known from 10 streams and three mountainous regions, Grand Teton National Park, the Absaroka-Beartooth Wilderness, and Glacier National Park, all within the Rocky Mountains. Evidence from the mitochondrial genome indicates contemporary but rare gene flow among mountain ranges, and much lower genetic differentiation among populations versus ecologically similar, confamilial species. Here, we incorporated a nuclear genome-wide perspective via double-digest restriction-site associated DNA sequencing (ddRAD) to better characterize population structure, demographic history, and species boundaries within this imperiled species.

Scott Hotaling (Primary Presenter/Author), University of Kentucky, scott.hotaling@uky.edu;


J. Joseph Giersch ( Co-Presenter/Co-Author), USGS Northern Rocky Mountain Science Center, jgiersch@usgs.gov;


Debra Finn ( Co-Presenter/Co-Author), Missouri State University, dfinn@missouristate.edu;


Lusha Tronstad ( Co-Presenter/Co-Author), Wyoming Natural Diversity Database, University of Wyoming, tronstad@uwyo.edu;


Clint Muhlfeld ( Co-Presenter/Co-Author), U.S. Geological Survey, cmuhlfeld@usgs.gov;


David Weisrock ( Co-Presenter/Co-Author), University of Kentucky, dweis2@uky.edu;


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