SFS Annual Meeting

5/24/2018  |   09:00 - 09:15   |  410 A

EVALUATING POTENTIAL EFFECTS OF BIGHEADED CARPS ON FATTY ACID PROFILES OF MULTIPLE TROPHIC LEVELS IN LARGE RIVERS OF THE MIDWEST Literature indicates that the establishment of bigheaded carp has led to a reduction in condition of native planktivores and may detrimentally affect other trophic levels by altering the base of aquatic food webs. We used fatty acids to evaluate potential effects of bigheaded carp on taxa from multiple trophic levels in the Upper Mississippi, Illinois, and St. Croix rivers. Seston fatty acid concentrations were highest in the Illinois River, indicating that these locations had abundant, high-quality basal food resources despite hosting the greatest carp densities. Fatty acid content of gizzard shad was lowest in the Illinois River, and multivariate models identified bigheaded carp densities as the predictive factor that explained the greatest amount of variability. Zooplankton abundance has been greatly reduced after bigheaded carp establishment in the Illinois River, which may explain the disconnect between the gizzard shad fatty acids and the plentiful, high-quality phytoplankton in that river. Freshwater mussel, hydropsychid caddisfly, and bluegill fatty acids did not reflect the carp abundance gradient, indicating that these species may be less affected. Our data provide additional evidence that bigheaded carp are negatively affecting native planktivores such as gizzard shad.

Andrea Fritts (Primary Presenter/Author), U.S. Geological Survey, afritts@usgs.gov;


Brent Knights (Co-Presenter/Co-Author), U.S. Geological Survey, bknights@usgs.gov;


William Richardson (Co-Presenter/Co-Author), U.S. Geological Survey, wrichardson@usgs.gov;


Lynn Bartsch (Co-Presenter/Co-Author), U.S. Geological Survey, lbartsch@usgs.gov;


Michelle Bartsch (Co-Presenter/Co-Author), U.S. Geological Survey, mbartsch@usgs.gov;


Jon Vallazza (Co-Presenter/Co-Author), U.S. Geological Survey, jvallazza@usgs.gov;


Rebecca Kreiling (Co-Presenter/Co-Author), U.S. Geological Survey, rkreiling@usgs.gov;


Sean Bailey (Co-Presenter/Co-Author), U.S. Geological Survey, sbailey@usgs.gov;


Toben Lafrancois (Co-Presenter/Co-Author), Northland College, tlafrancois@northland.edu ;


Byron Karns (Co-Presenter/Co-Author), National Park Service, byron_karns@nps.gov;


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5/24/2018  |   09:15 - 09:30   |  410 A

LONG-TERM ZOOPLANKTON COMMUNITY PATTERNS IN LAKE CHAMPLAIN, USA: THE ROLE OF INVASIVE SPECIES IN RE-STRUCTURING LAKE FOOD WEBS. Freshwater lakes provide ideal habitat for invasive species that may deteriorate ecological integrity by altering food web dynamics. Lake Champlain Long-term patterns from 1992-present illustrate the impact of invasive species on the pelagic food web. Zooplankton exhibited major shifts including a decline in rotifer abundance in the mid-1990s, following invasion of zebra mussels. More recent community shifts represent invasion of Alewife (Alosa pseudoharengus) and Spiny Waterflea (Bythotrephes longimanus). The primary driver of change in Lake Champlain’s plankton over the past two decades appears to be species invasions rather than patterns in water quality or trophic status. Food web analysis suggests zebra mussel direct impacts on Rotifers, via predation, with potential indirect effects on Cladocera, Copepods, and Mysids. Impacts of Alewife and Spiny waterflea invasion in the mid-2000s and 2014, respectively, occurred on selected larger bodied Cladocera and Copepod taxa. Post- invasion patterns in Lake Champlain’s pelagic plankton communities illustrate the threat that invasive species pose to the integrity of freshwater ecosystems.

Timothy Mihuc (Primary Presenter/Author), SUNY Plattsburgh, mihuctb@plattsburgh.edu;


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5/24/2018  |   09:30 - 09:45   |  410 A

THE AFTERMATH OF DREISSENID INVASIONS ON STREAM BENTHIC MACROINVERTEBRATE AND FISH COMMUNITIES Since their Great Lakes invasion, dreissenid mussels have impacted freshwater systems by altering nutrient cycling and community structure of macroinvertebrates and fish; however, most research has focused on the effects of living organisms. We investigated the impacts of dreissenid shells on fish and benthic macroinvertebrate communities in southeastern Michigan rivers. In the Rouge and Huron Rivers, macroinvertebrate were assessed using EPA’s rapid bioassessment, and seining used to collect fish for an evaluation of community composition. Within each river we sampled 8 sites, 4 in invaded and 4 in uninvaded sections of each river, totaling 16 locations. The fish community was evaluated at all sites during spawning and post-spawning periods, and the invertebrate community was evaluated in late summer. We found no relation between dreissenid shell density and fish spawning in either river, however, centrarchids were more prevalent at uninvaded sites compared to invaded sites. Macroinvertebrate communities were more diverse, with higher richness and EPT taxa in non-invaded when compared to invaded sites. This research shows that the presence of dreissenid shells can alter invertebrate communities, potentially degrading fish spawning areas for centrarchids, indicating an overall decline in stream ecosystem health.

Darrin Hunt (Primary Presenter/Author), University of the Ozarks, dhunt@ozarks.edu;


Donna Kashian (Co-Presenter/Co-Author), Wayne State University, dkashian@wayne.edu;


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5/24/2018  |   09:45 - 10:00   |  410 A

A BOBBER’S PERSPECTIVE ON ANGLER-DRIVEN VECTORS OF INVASIVE SPECIES TRANSMISSION Prevention of aquatic invasive species transmission by recreational fishing and boating is a fundamental management challenge. These activities can entrain non-native plants and animals via tangled lines, bait buckets, or hull encrustation, leading to introductions into new waterbodies. With hundreds of millions of people participating in fishing trips each year, understanding angler movement behavior can provide critical insight into the most effective locations and scales at which to apply preventative measures. Angler behavior is often inferred from infrequently and sparsely conducted surveys that provide limited spatial and temporal insight into this challenge. Here we capitalize on a big data opportunity provided by ReelSonar’s recently launched iBobber, a sonar-enabled bobber with over 3,000,000 records of fishing location, water depth, and environmental variables collected over three years. By quantifying geographic patterns of fishing activities and assessing how these patterns change seasonally, we will explore angler behavior in terms of fishing frequency and distance traveled between sites, and characterize the attributes of fished ecosystems. Our study offers novel insight into spatiotemporal patterns of angler behavior and carries important implications for predicting and preventing future transmission of aquatic invasive species via recreational fishing.

Rachel Fricke (Primary Presenter/Author), University of Washington, rmfricke@uw.edu;


Mathis L. Messager (Co-Presenter/Co-Author), Department of Geography, McGill University, Canada | RiverLy Research Unit, INRAE, France, mathis.messager@mail.mcgill.ca;


Dustin Martin (Co-Presenter/Co-Author), ReelSonar, Inc., dustin@reelsonar.com;


Julian Olden (Co-Presenter/Co-Author), University of Washington, olden@uw.edu;


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5/24/2018  |   10:00 - 10:15   |  410 A

LONG-TERM RESPONSES OF NATIVE BIVALVES (UNIONIDAE AND SPHAERIIDAE) TO THE DREISSENID INVASION OF THE FRESHWATER TIDAL HUDSON RIVER A 28-year study documented complicated responses of native bivalves to the dreissenid invasion of the Hudson River. Early in the invasion (1993-2000), populations of native species declined steeply, reaching 0-35% of pre-invasion densities by the year 2000. These declines in population density were accompanied by large declines in body mass, body condition, and recruitment. Since the year 2000, sphaeriid populations have recovered to pre-invasion densities, and body condition, recruitment, and juvenile growth of unionids have recovered substantially, even though the number of dreissenids in the river has not declined. However, unionid populations did not recover, and 2 of 3 formerly common unionid species have not been collected in several years. The 3rd species appears about to disappear. Statistical and demographic models suggest that the dynamics of native populations were more likely driven by exploitative competition than by fouling. They also suggest that changes in dreissenid body size may have modulated the strength of this exploitative competition over the course of the invasion. The lack of recovery of unionid populations appears to be a result of failure of juveniles to reach adulthood, probably because of high mortality from predators.

David Strayer (Primary Presenter/Author), Cary Institute of Ecosystem Studies, strayerd@caryinstitute.org;


Heather Malcom (Co-Presenter/Co-Author), Cary Institute of Ecosystem Studies, malcomh@caryinstitute.org;


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5/24/2018  |   10:15 - 10:30   |  410 A

DIFFERENTIAL EFFECTS OF BYTHOTREPHES LONGIMANUS ON POPULATION GROWTH RATES OF LAKE MICHIGAN ZOOPLANKTON SPECIES Aquatic food webs have been dramatically altered by the introduction of nonindigenous species. For instance, shortly after its introduction into the Great Lakes, the non-native predatory zooplankter, Bythotrephes longimanus, is thought to have significantly changed the community structure of mesozooplankton. However, ongoing effects of B. longimanus on zooplankton community structure and dynamics are not well understood and can be difficult to disentangle from other factors (e.g., seasonality). To address this gap, we used generalized additive models to examine the effects of B. longimanus on estimated specific growth rates for common species in Lake Michigan, generated from long-term, offshore time series data (1994-2012). Our results suggest that zooplankton species differ in the occurrence and magnitude of B. longimanus effects, with observed differences consistent with expectations based on experimental measurements of consumptive and nonconsumptive effects of B. longimanus. Estimated reductions in growth rate (e.g., estimated 20% reduction in Daphnia mendotae population growth) likely alter the availability of these species as prey for important prey fish. Our results thus provide valuable, field-based evidence for ongoing impacts of this invader in Lake Michigan, with potential consequences for ecosystem-scale processes.

Henry Vanderploeg (Co-Presenter/Co-Author), NOAA Great Lakes Environmental Research Laboratory, Henry.Vanderploeg@noaa.gov;


Steven Pothoven (Co-Presenter/Co-Author), NOAA Great Lakes Environmental Research Laboratory, steve.pothoven@noaa.gov;


Ashley Elgin (Co-Presenter/Co-Author), NOAA Great Lakes Environmental Research Laboratory, ashley.elgin@noaa.gov;


Scott Peacor (Co-Presenter/Co-Author), Michigan State University, peacor@msu.edu;


John Marino (Primary Presenter/Author), Bradley University, jmarino@fsmail.bradley.edu;


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