SFS Annual Meeting

Teresa Newton (Primary Presenter/Author)
U.S. Geological Survey, Upper Midwest Environmental Sciences Center, tnewton@usgs.gov;

Danielle Schultz (Co-Presenter/Co-Author)
University of Wisconsin - La Crosse, dschultz@uwlax.edu;

Robert Francis (Co-Presenter/Co-Author)
U. S. Geological Survey, rfrancis@usgs.gov;

Abstract: Despite a heightened global concern for native freshwater mussels, fundamental research on mussel ecology in large rivers is lacking. A common goal of resource managers in the upper Mississippi River (UMR) is to restore and sustain native mussel assemblages. We designed reach-wide systematic surveys to estimate the number of species, population size, abundance, and recruitment of mussels across six reaches (i.e., navigation pools) of the UMR. A total of 3460 mussels were obtained in 1842-0.25 m2 samples. Across all six reaches we documented 28 live species, with a given reach containing 16-23 species. Population estimates varied almost 10-fold across reaches, ranging from 61-592 million mussels. Mean reach density varied about 2-fold and ranged from 2.9-5.4 mussels/m2. Evidence of strong recruitment by juveniles was observed; the percent of the population comprised of juveniles ranged from 14-57% across the six reaches and 61-78% of the species were found as juveniles. Interestingly, about 60% of the individuals were found in about 10% of the aquatic area. Collectively, these data indicate that the UMR, despite being regulated and impounded, contains a dense, diverse, and reproducing assemblage of native freshwater mussels.

Gretchen Rollwagen-Bollens (Primary Presenter/Author)
Washington State University, rollboll@wsu.edu;

Stephen M. Bollens (Co-Presenter/Co-Author)
Washington State University, sbollens@wsu.edu ;

Kristin Connelly (Co-Presenter/Co-Author)
Washington State University, kristin.connelly@wsu.edu;

Julie Zimmerman (Co-Presenter/Co-Author)
Washington State University Vancouver, juliezimmerman@wsu.edu;

Alixandra Coker (Co-Presenter/Co-Author)
Camas High School, Camas, WA, USA, alixandra.coker@camas.wednet.edu;

Abstract: Multiple factors influence large river phytoplankton dynamics, however eutrophication brings urgency to understanding how riverine phytoplankton respond to variable nutrient availability. Based on suggestive preliminary data, from May-September 2018 we undertook monthly 5-day experiments with the natural lower Columbia River (CR) phytoplankton assemblage incubated with amended NO3, PO4 and SiO4 to test for nutrient limitation. Treatment and non-amended control bottles were sampled daily for nutrients and chl a levels, as well as for assessment of phytoplankton composition and biomass. Phytoplankton biomass was lowest in May, when ambient nutrient concentrations were highest, and highest in August, when ambient nutrients were lowest. Diatom biomass dominated in spring, but cyanobacteria biomass increased substantially in late summer. Significantly higher phytoplankton biomass was observed in nutrient-amended treatments in June, July and September, indicating nutrient limitation in the lower CR during those months. Statistical results showed these increases were significantly associated with amended PO4 and SiO4, and to a lesser degree amended NO3 and temperature. Thus, the lower CR may not be conducive to phytoplankton growth during summer, and such conditions may become more prevalent as temperature increases under climate change.

Alfredo Mojica (Primary Presenter/Author)
Federal University of Alagoas, alfredo.mojica@penedo.ufal.br;

Abstract: The soundscape was evaluated using the passive acoustic method. Underwater recordings were made in 14 locations between dam and the mouth of São Francisco River (240 km) in December 2019 and 2020, detected different types of biological and anthropogenic sounds. The sounds production of at least 2 types of crustaceans and 18 types of fish. The sounds made by shrimp, which occurred mainly in the late afternoon and early morning. The average values of the high and low frequencies were 8.4 ± 0.8 kHz and 3.7 ± 0.3 kHz respectively, and the central frequency of 5.5 ± 0.09 kHz. In regions near to the estuary, two others types of shrimp sounds were identified with frequency between 1 and 15 kHz. Fish sounds presented frequencies between 0.2 and 1.5 kHz. The acoustic landscape presented characteristics similar to estuarine ecosystems 10 km from the mouth of river. Anthropogenic noises were also detected from different vessels with a wide frequency band (between 0.2 and 15 kHz), which can mask biological sounds. Passive acoustics tool can be used as a tool for monitoring biological and anthropic sounds, as well river and estuary environments conditions.

Daelyn A. Woolnough (Co-Presenter/Co-Author)
Central Michigan University, wooln1d@cmich.edu;

Todd J. Morris (Co-Presenter/Co-Author)
Great Lakes Laboratory for Fisheries and Aquatic Sciences, Fisheries and Oceans Canada, todd.morris@dfo-mpo.gc.ca;

David T. Zanatta (Co-Presenter/Co-Author)
Central Michigan University, zanat1d@cmich.edu;

Shay S. Keretz (Primary Presenter/Author)
Central Michigan University, allre1s@cmich.edu;

Abstract: The establishment of dreissenid mussels within the Lake St. Clair and the St. Clair-Detroit River system of the Laurentian Great Lakes region seemingly pushed native freshwater mussels (Bivalvia: Unionidae) to extirpation. To assess remnant unionid and invasive dreissenid populations in these rivers, the Detroit River was surveyed in 2019 using a mixture of stratified random, historical, and potential refuge sites (n = 56). Two hundred and twenty live unionids representing 11 species were found among 5 sites and more than 2,000 unionid shells of 31 species were collected. The highest dreissenid densities were concentrated in the upper half of the Detroit River and estimated densities ranged from 0 to 5,673 live dreissenids m-2. Species distribution models using MaxEnt have been created for unionids and dreissenids using the data collected from the Detroit River in 2019 revealing approximately 12% of the total Detroit River area and 3% of the total St. Clair River area to be suitable habitat for unionids. Models will be validated in the St. Clair River in summer 2021 and will facilitate further understanding of native and invasive mussel distributions in large river systems.

Molly Van Appledorn (Primary Presenter/Author)
U.S. Geological Survey, Upper Midwest Environmental Sciences Center, mvanappledorn@usgs.gov;

KathiJo Jankowski (Co-Presenter/Co-Author)
U.S. Geological Survey, Upper Midwest Environmental Sciences Center, kjankowski@usgs.gov ;

Kaija Gahm (Co-Presenter/Co-Author)
Yale University , kaija.gahm@yale.edu;

Jason Rohweder (Co-Presenter/Co-Author)
U.S. Geological Survey, Upper Midwest Environmental Sciences Center, jrohweder@usgs.gov;

Abstract: Large wood plays important geomorphic and ecological roles in rivers and is widely used as a habitat restoration tool. Historically, floodplain land use and wood removal altered wood dynamics in fluvial systems globally, including great rivers like the Upper Mississippi River System (UMRS). We know little about the distribution and dynamics of large wood in the UMRS despite its ecological importance and use in habitat restoration projects. We assessed 25 years of spatial wood occurrence data collected during fisheries sampling by the Upper Mississippi River Restoration Program in six reaches of the UMRS. We found significant declines in wood occurrence in most river reaches, and strong relationships between wood presence and aquatic habitat type, with the greatest abundance occurring in side channels. Wood presence was correlated with hydrogeomorphic factors such as water depth, wing dam or revetment presence, indicating transport- and source-related variables, and river infrastructure, have important influences on wood dynamics in great rivers. Our results show that large wood is a spatially and temporally dynamic component of the UMRS, and hydrogeomorphic variation should be considered when evaluating its use and longevity in large river habitat restoration projects.

Kristen Bouska (Co-Presenter/Co-Author)
U.S. Geological Survey, kbouska@usgs.gov;

Nathan De Jager (Co-Presenter/Co-Author)
US Geological Survey, Upper Midwest Environmental Sciences Center, 2630 Fanta Reed Road, La Crosse, WI 54603, ndejager@usgs.gov;

Brian Ickes (Co-Presenter/Co-Author)
US Geological Survey, bickes@usgs.gov;

KathiJo Jankowski (Co-Presenter/Co-Author)
U.S. Geological Survey, Upper Midwest Environmental Sciences Center, kjankowski@usgs.gov ;

Danelle Larson (Co-Presenter/Co-Author)
U.S. Geological Survey, dmlarson@usgs.gov ;

Jason Rohweder (Co-Presenter/Co-Author)
U.S. Geological Survey, Upper Midwest Environmental Sciences Center, jrohweder@usgs.gov;

James Rogala (Co-Presenter/Co-Author)
U.S. Geological Survey, jrogala@usgs.gov;

Molly Van Appledorn (Co-Presenter/Co-Author)
U.S. Geological Survey, Upper Midwest Environmental Sciences Center, mvanappledorn@usgs.gov;

Andrew Bartels (Co-Presenter/Co-Author)
Wisconsin Department of Natural Resources, abartels@contractor.usgs.gov;

Alicia Carhart (Co-Presenter/Co-Author)
Wisconsin Department of Natural Resources, Alicia.Carhart@wisconsin.gov;

Deanne Drake (Co-Presenter/Co-Author)
Wisconsin Department of Natural Resources, Deanne.Drake@wisconsin.gov;

Shawn Giblin (Co-Presenter/Co-Author)
Wisconsin Department of Natural Resources, shawn.giblin@wisconsin.gov;

John Kalas (Co-Presenter/Co-Author)
Wisconsin Department of Natural Resources, John.Kalas@wisconsin.gov;

Kyle Bales (Co-Presenter/Co-Author)
Iowa Department of Natural Resources, kyle.bales@dnr.iowa.gov;

Melvin Bowler (Co-Presenter/Co-Author)
Iowa Department of Natural Resources, melvin.bowler@dnr.iowa.gov;

Robert Burdis (Co-Presenter/Co-Author)
Minnesota Department of Natural Resources, robert.burdis@state.mn.us;

Eric Lund (Co-Presenter/Co-Author)
Minnesota Department of Natural Resources, Eric.Lund@state.mn.us;

Kristopher Maxson (Co-Presenter/Co-Author)
Illinois Natural History Survey, Illinois River Biological Station, kmax87@illinois.edu;

Levi Solomon (Co-Presenter/Co-Author)
Illinois Natural History Survey, soloml@illinois.edu;

Jeffrey Houser (Primary Presenter/Author)
USGS Upper Midwest Environmental Sciences Center, jhouser@usgs.gov;

Abstract: Large floodplain rivers are complex and spatially extensive. Collecting and learning from data spanning their longitudinal and lateral gradients is challenging. The Long Term Resource Monitoring element of the Upper Mississippi River Restoration Program has monitored 6 reaches of the Upper Mississippi and Illinois rivers since 1993. These reaches range in length from 38 to 125 river km, span 1500 river km, and contain diverse aquatic and terrestrial areas. Our recent assessment of long-term trends found a long-term increase in discharge throughout the system. Total phosphorus and total suspended solids decreased in some study reaches and tributaries, but total nitrogen exhibited few long-term trends. Backwater depth has decreased in some areas due to sedimentation. In some reaches, water clarity and vegetation abundance have increased and feedbacks between them may have sustained that change during recent years of high discharge. Floodplain forest area declined in most areas, likely due to long-term changes in hydrology. Bigheaded carps have proliferated in some study reaches with diverse effects on the food web and ecosystem productivity. This comprehensive river assessment is intended to inform the restoration and management of the ecosystem.

Ryan Dunbeck (Primary Presenter/Author)
University of South Dakota, ryan.dunbeck@coyotes.usd.edu;

Jeff Wesner (Co-Presenter/Co-Author)
University of South Dakota, Jeff.Wesner@usd.edu;

Abstract: Invasive bigheaded carps (Hypophthalmichthys nobilis and H. molitrix), formerly referred to as Asian carps, are generalist consumers that may directly compete with native planktivores by modifying the biomass and community structure of local plankton populations. Much of the Missouri River Basin (MRB) has been colonized by bigheaded carps except for some sites upstream of dispersal barriers like dams. To determine the potential impacts of bigheaded carps on river communities, we collected phytoplankton from 33 sites in the MRB and compared results to an identical survey conducted 70 years ago. Preliminary analysis suggests differences in the phytoplankton community, regardless of the presence of bigheaded carps, in both current phytoplankton density (individuals/ml) and community structure when compared to past data. Consistent with historical data, phytoplankton density in tributaries was several orders of magnitude greater than in the mainstem Missouri River. Historical increasing downstream trends in phytoplankton abundance within MRB tributaries, however, were not observed in recent data. Comparing current phytoplankton data from both above and below impoundments in the MRB to past studies may provide further insight into potential bottom-up effects from bigheaded carp colonization.

Hilary Dugan (Co-Presenter/Co-Author)
University of Wisconsin-Madison, hdugan@wisc.edu;

Madeline Magee (Co-Presenter/Co-Author)
Wisconsin Department of Natural Resources, madeline.magee@wisconsin.gov;

KathiJo Jankowski (Co-Presenter/Co-Author)
U.S. Geological Survey, Upper Midwest Environmental Sciences Center, kjankowski@usgs.gov ;

Robert J. Mooney (Primary Presenter/Author)
Center for Limnology, University of Wisconsin - Madison, rjmooney@wisc.edu;

Abstract: In rivers that experience winter ice cover, overwintering conditions play a central role in the survival of fishes. Centrarchids rely on backwater habitats and their populations can be bottlenecked by suitable habitat availability, which is often defined by the ranges of depth (>1 m), flow (<0.01 m/s), temperature (>1 °C) and dissolved oxygen (>5 mg/L). However, despite the importance of maintaining overwintering habitat, there remains uncertainty in the spatiotemporal drivers of midwinter conditions. We paired aquatic connectivity metrics with long-term midwinter data from field stations along the Upper Mississippi River System (UMRS) to evaluate the drivers of backwater habitat conditions. We found that presence of suitable habitat varied throughout the UMRS and within individual sites over the last 25 years. Increased ice and snow depth were associated with reduced habitat suitability. Further, increased connectivity between backwaters and lotic habitats led to elevated flow rates and reduced suitable habitat. Understanding how connectivity and climate variability combine to influence backwater environments is critical to maintaining sustainable fish communities throughout the UMRS, especially as we expect winter length and severity to change and mediate the spatial drivers of winter conditions.