5/18/2015  |   13:30 - 13:45   |  103DE

EFFECTS OF CONNECTIVITY ON FLOODPLAIN MACROINVERTEBRATE COMMUNITIES ON A LARGE NEW ZEALAND RIVER SYSTEM Connectivity of rivers with floodplains is regulated in many lowland river systems worldwide to allow for human population growth and agricultural development. Disconnection of floodplains has been linked to declines in fish populations but comparatively little is known about responses of macroinvertebrate communities. We sampled macroinvertebrates in (i) terrestrial habitats characterised by different vegetation types and fed by different donor systems during a large flood, and (ii) 34 floodplain ponds during an inter-flood period. Macroinvertebrate communities in flooded terrestrial habitats were similar to those in flooded wetlands and lake outlets, and distinct from stream tributary and mainstem faunas, suggesting colonisation of inundated land predominantly from floodplain lake and wetland donor systems. In constructed floodplain ponds, macroinvertebrate community composition was affected by factors strongly associated with riverine connectivity: flood frequency, permanence, and the abundance of invasive fish. Our work highlights that achieving biodiversity returns through re-creation of natural connectivity can be compromised by the modified composition of biotic communities, and indicates that controlled connectivity with floodplains is required to achieve multiple goals.

Kevin Collier (Primary Presenter/Author), University of Waikato, kcollier@waikato.ac.nz;


Jeremy Garrett-Walker (Co-Presenter/Co-Author), University of Waikato, jgarrett@waikato.ac.nz;


Konrad Górski (Co-Presenter/Co-Author), Universidad Católica de la Santísima Concepción, kgorski@ucsc.cl;

5/18/2015  |   13:45 - 14:00   |  103DE

ASSEMBLAGE CHANGE IN A LARGE RIVER ECOSYSTEM: HISTORICAL AND RECENT FOOD-WEB COMPARISONS We identified a community shift in the fish assemblage of the Wabash River using a long-term dataset of electrofishing data from 1974-2008. The fish assemblage changed in approximately 1992 from a planktivore-omnivore dominated community to benthic invertivore dominated. A concurrent study on agricultural nutrient contributions to the river during the same time period indicated significant negative correlations of organic nitrogen with benthic invertivore fish relative abundance (and postitive correlations with phosphorus inputs). We sampled stomachs of planktivores from archival collections, as a representation of historical phytoplankton in the river. Our analyses showed phytoplankton communities of the 1960s that were dominated by green algae, a relatively high quality food source to fishes. The current community is dominated by blue-greens and diatoms that have less nutritional quality to fishes. The carbon and nitrogen isotope ratios of consumers were used to reconstruct historical food webs for comparison to recent food webs, using fishes and mussel specimens from recent and archival natural history collections. C and N isotope ratios in historical food webs were different from recent food webs.

Mark Pyron (Primary Presenter/Author), Ball State University, mpyron@bsu.edu;


Jesse Becker (Co-Presenter/Co-Author), Ball State University, jcbecker@bsu.edu;


Kevin Wyatt (Co-Presenter/Co-Author), Ball State University, khwyatt@bsu.edu;


Dawn DeColibus (Co-Presenter/Co-Author), Ball State University, dtdecolibus@bsu.edu;


Luke Etchison (Co-Presenter/Co-Author), Ball State University, letchison2@bsugmail.net;


Mario Minder (Co-Presenter/Co-Author), Ball State University, mmminder@bsu.edu;


Brent Murry (Co-Presenter/Co-Author), US Fish and Wildlife Service, Brent_murry@fws.gov;


Kyle Broadway (Co-Presenter/Co-Author), Central Michigan University, broadwaybio@gmail.com;


Rebecca Logsdon (Co-Presenter/Co-Author), Purdue University, rlogsdo@purdue.edu;


Indrajeet Chaubey (Co-Presenter/Co-Author), Purdue University, ichaubey@purdue.edu;

5/18/2015  |   14:00 - 14:15   |  103DE

HISTORICAL CHANGES IN FOOD WEB STRUCTURE OF THE MISSISSIPPI AND OHIO RIVERS IN RESPONSE TO DAMMING Damming is the single most important factor influencing river connectivity and its ecological functions. How do food webs respond to massive structural changes to river systems? The Mississippi and Ohio rivers have perhaps the best historical samples in the USA, and provided a unique opportunity to look at food web drivers over long time scales. Trophic position was evaluated using amino acid compound specific stable isotope analysis of fish museum specimens. We found a shift in trophic positions in the Mississippi River in response to the major damming events. Discharge, gage height, and temperature were not correlated with the shift in trophic position. The physical presence of the dams altered the complexity of the system, altering food web structure. The Ohio River did not show this same change in food web structure with the addition of the dams. This probably reflects the minimal change in complexity in the Ohio River with construction of the dams. The dams operate differently in the two river systems, and when habitat structure is altered from a dam, the food web is fundamentally changed.

Rachel Bowes (Primary Presenter/Author,Co-Presenter/Co-Author), University of Kansas, Kansas Biological Survey, rebowes.wildlife@gmail.com;


James H. Thorp (Co-Presenter/Co-Author), University of Kansas/Kansas Biological Survey, thorp@ku.edu;


Michael Delong (Co-Presenter/Co-Author), Winnona State University, MDelong@winona.edu ;

5/18/2015  |   14:15 - 14:30   |  103DE

INVESTIGATION OF FRESHWATER MUSSEL GLOCHIDIA PRESENCE ON ASIAN CARP AND NATIVE FISHES OF THE ILLINOIS RIVER Asian carp have been reported to serve as fish hosts to freshwater mussels in their native territories, but no one has conducted research on the potential for Silver, Bighead, or Black Carp to host North American freshwater mussels or if they serve as reproductive sinks. Native fishes and non-native carp species were collected from the Illinois River Basin during summer of 2014. Preserved fins, tail, and gills of native and non-natives were observed, of which gills were first soaked with a 5% potassium hydroxide solution for 20 minutes to increase transparency. Our primary objective was to evaluate the potential presence of glochidia on non-native fishes in the Illinois River system; if found, this would be the first documented record for Silver and Bighead Carp in North America and would provide great incentive to pursue further studies to elucidate if Asian carp could serve as a successful host fish for native mussels or if they are serving as reproductive sinks, a possibility that could have a major impact on the future stocks of currently imperiled freshwater mussels.

Sarah Douglass (Primary Presenter/Author), Illinois Natural History Survey, sabales@illinois.edu;


Alison Stodola (Co-Presenter/Co-Author), Illinois Natural History Survey, alprice@illinois.edu;


Andrea Fritts (Co-Presenter/Co-Author), Illinois Natural History Survey, afritts@illinois.edu;

5/18/2015  |   14:30 - 14:45   |  103DE

ANALYSIS OF LONG TERM PRIMARY PRODUCTION DATA IN KENTUCKY LAKE: CAN WE DETECT INVASIVE ASIAN CARP? Silver Carp (Hypopthalmicthys molitrix) have established populations throughout the Midwestern U.S and populations in Kentucky Lake have increased rapidly within the past decade. This project aims to understand potential impacts of Silver Carp on reservoir primary productivity by utilizing multivariate long term data analysis. Kentucky Lake primary production was analyzed both temporally and spatially with nonmetric multi-dimensional scaling (NMDS). Primary production was compared pre (1990-2004) and post invasion (2005-2013). Spatial analysis of primary production compared contrasting reservoir habitats (e.g embayment and main channel). To date, overall NMDS results show overlap between primary production pre-and-post invasion along with high intrasite variability, making it difficult to detect changes. However, some patterns show important differences in primary productivity post invasion and are being analyzed further. Whether the recent invasion of Silver Carp is negatively impacting Kentucky Lake is not yet clear. Future analysis will focus on developing year by year rankings based on limnological parameters to account for intrasite variability. Understanding long term trends in the Kentucky Lake ecosystem is important to understanding the invasion ecology of Silver Carp.

Benjamin Tumolo (Primary Presenter/Author), University of Wyoming, bbtumolo@gmail.com;


Michael Flinn (Co-Presenter/Co-Author), Murray State University, mflinn@murraystate.edu;

5/18/2015  |   14:45 - 15:00   |  103DE

ECOSYSTEM RESPONSES TO ASIAN CARP INVASION AND CONTROL: PATTERNS OF RIVERINE ZOOPLANKTON ABUNDANCE, BIOMASS, AND COMPOSITION Asian carp exert a strong indirect pressure on ecosystems through the planktivory. This talk summarizes projects that examine river zooplankton response to the arrival and removal of Asian carp over a 20 year period in the Illinois River. Plankton responses examined include; shifts in community composition since pre-Asian carp conditions, longitudinal patterns of plankton composition across a 250 kilometers gradient of Asian carp abundance, and an assessment of the potential for rapid recovery of the zooplankton to localized carp removals of between 2 -20 tones from a single floodplain backwater. Since Asian carp establishment in 2000, zooplankton abundance and biomass have both dramatically decreased. Although large bodied cladocerans and copepods were most affected the highly abundant rotifers, dominant in this and other large rivers systems, was also significantly reduced even though rotifer biomass was unaffected. Plankton community composition and dominance shifts markedly as carp arrived in 2000 but, to date, the localized removal efforts of a commercial fishing program have not reversed these shifts, even at a local level.

Andrew Casper (Primary Presenter/Author), Illinois Natural History Survey, afcasper@illinois.edu;


Collin J. Hinz (Co-Presenter/Co-Author), Illinois Natural History Survey, University of Illinois, collin.hinz@gmail.com;


Richard M. Pendleton (Co-Presenter/Co-Author), Illinois Natural History Survey, University of Illinois, richpend@illinois.edu;