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SFS Annual Meeting

Tuesday, June 4, 2024
15:00 - 16:30

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C10 Biogeochemistry

15:30 - 15:45 | Independence Ballroom D | IMPACT OF CLIMATE CHANGE AND RESTORATION ON PHOSPHORUS LOADING IN AN IMPAIRED WETLAND

6/04/2024  |   15:30 - 15:45   |  Independence Ballroom D

Impact of Climate Change and Restoration on Phosphorus Loading in An Impaired Wetland Around two-thirds of the coastal wetlands in Michigan have been lost to development and human modification. Restoring these wetlands can increase biodiversity through habitat rehabilitation and improved water quality. Prior agricultural practices at a coastal wetland restoration site in west Michigan have caused high legacy phosphorus concentration in sediments. Sediment dredging is being considered as a restoration tool to control internal phosphorus loading (IPL). Climate warming is resulting in increases to both mean temperature and temperature extremes, which may affect IPL. I examined the effects of both sediment dredging and climate warming on P dynamics in this wetland complex by incubating sediment cores in a controlled laboratory experiment. Unexpectedly, dredged sediment cores had higher phosphorus release rates throughout the incubation compared to undredged cores. Temperature regime had less of an effect on P flux and had varying effects overall. The observed results may be attributed to the extreme P saturation prevalent in both ponds. Ongoing analyses using generalized additive models aims to provide more insight into the complex incubation results. These preliminary results not only challenge the conventional knowledge surrounding dredging as a restoration technique, but also emphasize the importance of precursory research. This information will be crucial for our partner restoration team, as it will inform them on decisions surrounding the long-term success of the wetland restoration project.

Kate Lucas (Primary Presenter/Author), Annis Water Resources Institute - Grand Valley State University, lucakath@mail.gvsu.edu;

Alan Steinman (Co-Presenter/Co-Author), Annis Water Resources Institute-Grand Valley State University, steinmaa@gvsu.edu;

15:45 - 16:00 | Independence Ballroom D | INCREASING PHOSPHORUS TRENDS IN A NORTHERN PRAIRIE RIVER ARE LINKED TO INCREASING URBAN POPULATION AND HYDRO-CLIMATIC CONDITIONS

6/04/2024  |   15:45 - 16:00   |  Independence Ballroom D

Increasing phosphorus trends in a northern prairie river are linked to increasing urban population and hydro-climatic conditions Lake Winnipeg, Canada has been experiencing extensive nuisance and toxic algal blooms for over two decades. Research has linked these blooms to increased phosphorus loadings from tributary systems, particularly from the Red River. Phosphorus loads in the Red River were identified to be increasing nearly 20 years ago, however, there has been no recent assessment of phosphorus trends. More importantly, the key contributors to the loads have not been clearly identified. The goal of this study was to identify trends in concentrations and loads of the main phosphorus species (total phosphorus, particulate phosphorus, and dissolved phosphorus) and determine if these trends are temporally associated with changes in hydrologic, climatic, and anthropogenic conditions. We found that total phosphorus loads have more than tripled in the last 60 years due to increases in dissolved phosphorus, particularly during the snowmelt and summer seasons. Particulate phosphorus has not increased over the analyzed period of record. Increases in dissolved phosphorus are most associated with the post 1990 20% increase in urban populations along the Red River. Changes in river flow and climatic conditions also corresponded to P loads but could not be linked to concurrent changes in non-point activities, suggesting mobilization of legacy phosphorus stores from land and channel-based sources. Findings from this study indicate that P loads to Lake Winnipeg are still increasing, potentially exacerbating the eutrophication of the lake. However, our study indicates improved wastewater treatment as a means of potentially reducing P loadings to the Red River and Lake Winnipeg.

Adam Yates (Primary Presenter/Author), University of Waterloo, adam.yates@uwaterloo.ca;

Amy White (Co-Presenter/Co-Author), University of Waterloo, a33white@uwaterloo.ca;

Juwairiya Suhail (Co-Presenter/Co-Author), University of Waterloo, jsuhail@uwaterloo.ca;

Robert Brua (Co-Presenter/Co-Author), Environment Canada, bob.brua@ec.gc.ca;

16:00 - 16:15 | Independence Ballroom D | REDOX POTENTIAL IN A HYDRODYNAMICALLY VARIABLE COASTAL ESTUARY OF LAKE ERIE ACROSS TIME

6/04/2024  |   16:00 - 16:15   |  Independence Ballroom D

REDOX POTENTIAL IN A HYDRODYNAMICALLY VARIABLE COASTAL ESTUARY OF LAKE ERIE ACROSS TIME Many biogeochemical processes that occur in aquatic ecosystems are coupled reduction-oxidation (redox) reactions, which are highly driven by water level and oxygen availability in sediments. Great Lakes coastal estuaries can be hydrodynamically variable, potentially creating complex redox dynamics across temporal scales. We evaluated how changes in hydrology affected redox potential (Eh) and the cycling of key nutrients and metals in porewater and sediment collected from July – December 2023 in Old Woman Creek, a coastal estuary of Lake Erie in Huron, OH. Over the six-month time span, sediment redox potential varied with overlying water depth. Redox potential in the top 10 cm of sediment was ~ -125 to 200 mV when overlying water was present and ~ 250 – 500 mV when it was absent. The pulses of oxidizing and reducing conditions were related to pulses in upstream discharge and the opening/closing of the barrier beach in the estuary. In July and August when no surface water was present, the highest concentrations of soluble reactive phosphorus (437 ug/L) and ammonium (7615 ug/L NH4+-N) were from surface sediments, while the highest nitrate (61 ug/L NO3--N) was from 30 cm into the sediment. These results suggest that redox potential and nutrient cycling are not only related to ecosystem wide hydrology, but also fine scale changes in water depth within the sediments. Understanding how redox potential varies across time within a hydrodynamically variable estuary will better inform how nutrients and metals are cycled in these ecosystems and the models that use this data.

Erin Eberhard (Primary Presenter/Author), Kent State Univeristy , ekeberha@mtu.edu;

Talia Pope (Co-Presenter/Co-Author), Kent State University, tpope8@kent.edu;

Gil Bohrer (Co-Presenter/Co-Author), Ohio State University, bohrer.17@osu.edu;

Elizabeth Herndon (Co-Presenter/Co-Author), Oak Ridge National Laboratory, herndonem@ornl.gov;

Chelsea Monty-Bromer (Co-Presenter/Co-Author), Cleveland State University, c.montybromer@csuohio.edu;

Tim Morin (Co-Presenter/Co-Author), SUNY-ESF, thmorin@esf.edu;

John Senko (Co-Presenter/Co-Author), University of Akron, senko@uakron.edu;

Lauren Kinsman-Costello (Co-Presenter/Co-Author), Kent State University, lkinsman@kent.edu;

16:15 - 16:30 | Independence Ballroom D | SEASONAL IMPACTS ON ECOSYSTEM STOICHIOMETRY AND FLUXES IN A SMALL, NON-PERENNIAL SOUTHEASTERN STREAM

6/04/2024  |   16:15 - 16:30   |  Independence Ballroom D

Seasonal Impacts on Ecosystem Stoichiometry and Fluxes in a Small, Non-Perennial Southeastern Stream Climate change is anticipated to alter surface water connectivity in the Southeast USA, potentially shifting the processing and transport of carbon (C), nitrogen (N), and phosphorus (P) in headwaters to downstream ecosystems. However, we have limited understanding as to how seasonality and flow may differentially influence dissolved and particulate C:N:P stoichiometry across headwater streams. To address this knowledge gap, we assessed dissolved and particulate C and nutrient dynamics 1) across the network and 2) at the outlet of a non-perennial, headwater stream in northeastern Alabama, USA. On five occasions over 2022, we collected samples for dissolved organic C, dissolved inorganic N, and soluble reactive P, as well as particulate C, N, and P (as seston) from seven sites throughout the network. At the outlet, we collected high-frequency absorbance spectra data to correlate to C and N chemistry. Throughout the year, particulate C:N and C:P consistently decreased, while dissolved C:N and C:P were highest during the highest flow sampling conditions, regardless of season. Moving from upstream to downstream, dissolved C:N and C:P increased while particulate C:N and C:P decreased, suggesting sources and demand for C and nutrients differ by form. Ongoing work includes using high-frequency spectral data to assess how flow and season impact C:N:P stoichiometry. Critically, our study suggests the stoichiometric balance of C, N, and P are dynamic, even in headwater streams, and links between flow, season, and export will likely depend on the resource form and demand.

Stephen Plont (Primary Presenter/Author), University of Alabama, splont@ua.edu;

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

Arial Shogren (Co-Presenter/Co-Author), University of Alabama, ashogren@ua.edu;

Michelle Wolford (Co-Presenter/Co-Author), University of Alabama, mawolford@crimson.ua.edu;

Kaci Zarek (Co-Presenter/Co-Author), University of Alabama, kzarek@crimson.ua.edu;

Shannon Speir (Co-Presenter/Co-Author), University of Arkansas, slspeir@uark.edu;

Nate Jones (Co-Presenter/Co-Author), University of Alabama, cnjones7@ua.edu;

Carla L. Atkinson (Co-Presenter/Co-Author), University of Alabama, carlalatkinson@gmail.com;

16:30 - 16:45 | Independence Ballroom D | MUSSEL REESTABLISHMENT AS A CONSERVATION PRACTICE FOR URBAN STREAMS: AN INITIAL POST-STOCKING ASSESSMENT OF MUSSEL FEEDING BEHAVIOR AND SEDIMENT NUTRIENT FLUXES

6/04/2024  |   16:30 - 16:45   |  Independence Ballroom D

MUSSEL REESTABLISHMENT AS A CONSERVATION PRACTICE FOR URBAN STREAMS: AN INITIAL POST-STOCKING ASSESSMENT OF MUSSEL FEEDING BEHAVIOR AND SEDIMENT NUTRIENT FLUXES Urban streams often have elevated nutrient loads, but those that are restored to achieve riffle-pool sequences and riparian connectivity can see enhanced nutrient processing. However, physical restoration does not provide the same benefits as biological restoration. Unionid mussels can promote nutrient retention, transfer and removal but they are often absent from urban streams. Because mussels form assemblages and affect nutrient transformations through feeding, biodeposition, and bioturbation, they could mitigate nitrogen (N) loads. We have initiated a five-year plan to re-introduce multi-species unionid mussel assemblages to two physically-restored urban streams in Reston, VA. In an initial mussel stocking in July 2023, we added adult Eastern elliptio (Elliptio complanata) to Snakeden (1,578 mussels) and Glade (1,224 mussels) across an ~200 m reach in each stream. In August, we conducted in-situ feeding trials on individual mussels using the biodeposition method and chamber experiments to measure mussel-mediated sediment nutrient fluxes in comparison to a control upstream. We observed higher feeding and filtration rates at Snakeden, likely a result of higher quality food, whereas mussels at the Glade had high particle rejection rates (~85%). Both streams exhibited higher sediment ammonium fluxes in the presence of mussels ranging from 65 ?molN m-2 h-1 in Snakeden to 4,458 ?molN m-2 h-1 at Glade. We will continue to quantify ecological and biogeochemical effects of reintroducing native unionid mussels, including nutrient dynamics at the bed, reach and stream scale to understand the viability of mussel stocking as a conservation practice to mitigate nutrient pollution in urban streams.

Denise Bruesewitz (Primary Presenter/Author), Colby College, dabruese@colby.edu;

Sally Entrekin (Co-Presenter/Co-Author), Virginia Tech, sallye@vt.edu;

Chester Zarnoch (Co-Presenter/Co-Author), Baruch College, City University of New York, Chester.Zarnoch@baruch.cuny.edu;

Jess Jones (Co-Presenter/Co-Author), U.S. Fish and Wildlife Service, Jess_Jones@fws.gov;

Timothy Hoellein (Co-Presenter/Co-Author), Loyola University Chicago, thoellein@luc.edu;

Donya Mohamed (Co-Presenter/Co-Author), Virginia Tech, donyamohamed63@gmail.com;

Brendan Foster (Co-Presenter/Co-Author), U.S. Geological Survey, bfoster@usgs.gov;

16:45 - 17:00 | Independence Ballroom D | TEMPORAL VARIATION IN WATER QUALITY AND DISSOLVED ORGANIC CARBON IN THREE URBANIZED STREAMS

6/04/2024  |   16:45 - 17:00   |  Independence Ballroom D

Temporal variation in water quality and dissolved organic carbon in three urbanized streams In urban streams, high temporal resolution chemical and hydrologic data can aid in disentangling sources of organic matter. We monitored streams in three similarly sized (21.7–28.9 km2) adjacent watersheds near Boston, Massachusetts (USA) that vary in urban development (14–83% developed). Over one year, grab samples were collected every 1–2 weeks and analyzed for dissolved organic carbon (DOC) concentration and optical characteristics. Multiparameter sondes co-located with U.S. Geological Survey stream gages measured pH, conductivity, temperature, dissolved oxygen (DO), turbidity, and colored dissolved organic matter (CDOM) at 15-minute intervals. The most urbanized watershed (83% developed) consistently experienced the lowest DO and highest pH, conductivity, and temperature. The most urbanized stream also had lower DOC concentrations and higher autochthonous DOC with lower molecular weight than less developed sites. Interestingly, the DOC characteristics in the intermediate urbanization stream (64% developed) were very similar to those in the least urbanized stream (14% developed), suggesting that cross-site differences in DOC quality are driven not simply by percent watershed development, but may also be explained by active and legacy combined sewer overflows (CSOs) in the most urbanized watershed. During storm events, CDOM briefly decreased, then increased above pre-storm conditions in the low and intermediate developed streams, whereas in the highly developed stream, heavy precipitation and CSO events were associated with brief spikes in CDOM and pH. The responses of stream chemistry to seasonality and hydrologic events reveal that specific urban characteristics (such as infrastructure) result in varying sources and characteristics of DOC.

Annika Quick (Primary Presenter/Author), Virginia Wesleyan University, aquick@vwu.edu;

Allison Roy (Co-Presenter/Co-Author), U.S. Geological Survey, Massachusetts Cooperative Fish and Wildlife Research Unit, University of Massachusetts Amherst, aroy@eco.umass.edu;

Rebecca Hale (Co-Presenter/Co-Author), Smithsonian Environmental Research Center, haler@si.edu;

Kristina Hopkins (Co-Presenter/Co-Author), U.S. Geological Survey, khopkins@usgs.gov;

Shuo Chen (Co-Presenter/Co-Author), University of Georgia; University of Florida, schen83@crimson.ua.edu;

Liz Ortiz (Co-Presenter/Co-Author), Florida International University, lorti080@fiu.edu;