Introduction
The Mussel Performance in an Urban Stream Environment RFP was awarded in 2022 to a team of six research scientists: Sally Entrekin, PhD at Virginia Tech; Jess Jones, PhD at US Fish and Wildlife Service; Chester Zarnoch, PhD at Baruch College; Denise Bruesewitz at Colby College; Paul Angermeier, PhD at USGS; and Brandon Foster at USGS.
Request for Proposals
Second Request for Proposals: Mussel Performance in an Urban Stream Environment
Amount awarded to date: $755,500
Executive Summary
We will quantify ecological and biogeochemical effects of reintroducing native unionid mussels into two restored urban headwater streams in Reston, Virginia – Snakeden Branch and the Glade. A team of experts for each of the key components of the stated needs of Resource Protection Group, Inc. will provide a holistic and practical understanding of the outcomes of mussel restoration with respect to ecological processes, water quality, and biological communities. We will measure and analyze features of individual mussels, mussel beds, and stream reaches to describe the role mussels play in stream ecosystem function. Our fisheries management plan, focused on fish-host needs of the mussel populations, will be informed by species-specific responses of reintroduced mussels and their effectiveness in assimilating nutrients and changing physical and chemical conditions of the sediments to facilitate nitrogen removal via denitrification.

Project Team
- Sally Entrekin, PhD, is an aquatic entomologist and ecosystem ecologist in the department of Entomology at Virginia Tech. She will be the lead PI responsible for management and coordination of all aspects of the project. She will work with the USGS on understanding how macroinvertebrates and organic matter dynamics change and interact with restoration efforts in the context of mussels and without mussels. She will direct the Postdoctoral Fellow, co-advise a PhD student and mentor undergraduates.
- Jess Jones, PhD, is a restoration biologist with the US Fish and Wildlife Service stationed at Virginia Tech. He will be responsible for collecting and/or cultivating mussels, introducing them into the two streams in baskets and free-planted and his crew will monitor the survivorship, movement, and fitness of the mussels throughout the project duration. He will work closely with a full-time technician, Postdoctoral Fellow, co-advise a PhD student and work with fisheries on a mussel-fish action plan that supports mussel sustainability
- Chester Zarnoch, PhD, is a benthic ecologist who studies the structure and functioning of bivalves in estuarine and freshwater habitats, Baruch College CUNY, New York. He will be responsible for measuring mussel feeding rates in-situ following mussel re-introductions in baskets and in the benthos. He will work closely with others to collate data on mussel filtration rates of suspended particulates as well as the elemental composition (carbon, nitrogen, and phosphorus) of assimilated particulates and biodeposits released to the streambed. These data will be combined with the real time data to upscale dissolved and particulate nutrient dynamics to inform how many mussels are needed to mitigate or augment nutrient retention and flux.
- Denise Bruesewitz is a biogeochemist and ecosystem ecologist in Environmental Studies at Colby College, Maine. She will measure the role of mussels in baskets and benthos on nitrogen removal as a long-term storage via assimilation vs permanent removal via facilitating denitrification in mussel beds with higher organic matter, and nitrate. Dr. Bruesewitz will work in collaboration with Zarnoch to use sediment core incubations for denitrification. She will work with Zarnoch and Entrekin on whole-stream nutrient uptake, metabolism and denitrification.
- Paul Angermeier, PhD, is a fishery biologist and Assistant Unit Leader with the USGS Coope1-2rative Fish and Wildlife Research Unit at Virginia Tech. He will collaborate with the USGS fish-sampling crew and Jones to develop a fisheries management plan that informs mussel translocations based on existing fish assemblages and outlines management actions to ensure long-term maintenance of mussel populations. The plan will synthesize data on fish assemblage composition, population densities and age structure, dispersal abilities, and habitat suitability in the study streams – with an emphasis on species that are hosts for reintroduced mussels.
- Brendan Foster is a hydrologist at the USGS VA/WV Water Science Center. They collect water samples for nutrients and sediment using discrete and continuous monitoring approaches. Our proposed work depends on collaboration with USGS who is monitoring water downstream of the two restored streams, collecting benthic macroinvertebrates, and monitoring fish and physical habitat. USGS will expand their monitoring to accommodate additional carbon sampling at the stream monitoring station and longitudinal water-quality surveys throughout the two streams and closer to proposed mussel beds (see map).

Questions and Objectives
- Question 1: Can the mussels withstand the hydrologic regime of urban headwaters? Objective 1. Establish native mussel populations at densities predicted to affect nutrient retention and removal in the two-restoration stream reaches. Track mussel movement using pit tagged and tagged individuals. Propagules will be placed in baskets and secured to the stream bed using robust USGS anchoring methods in two sections of each restored stream (map above).
- Question 2: Are changes in nutrient retention, release, and removal measurable at the bed, reach, stream scales? Objective 2. Monitor water quality and fine particulates above and below all added mussel beds and baskets and scale to flux using USGS downstream gaging stations. Objective 3. Experimentally measure individual mussel feeding and nutrient effects (retention via assimilation and removal via increasing denitrification) using sediment core incubations with and without mussel and benthic macroinvertebrates in summer and late fall. In summer, measure mussel influence on fine particulate organic matter characteristics in a stream-side flume with and without macroinvertebrates. Measure whole-stream changes in nutrient uptake, metabolism and denitrification before mussels are added and each summer and late fall after mussels are added.
- Question 3. Can the existing (or managed) fish assemblages support mussel populations over the long term via their role as glochidia hosts? Objective 4. Develop appropriate fish management plans, aimed at sustaining mussel populations, based on fish species composition, population structure, and density in The Glade and Snakeden Branch.
- Question 4. What benefits and interactions do the mussels confer to the stream (measured as effect size on nutrient and macroinvertebrate community composition)? Objective. 5. Converge at a central location at the end of year 2 to review project status. If common and abundant mussels are established, effect sizes have been measured, then continue to objective 6, else revisit objective 1. Objective. 6. Combine an additional common and hardy mussel species. Re-deploy baskets and add mixed-mussel species to established beds. Continue summer and late-fall mesocosm and whole-stream nutrient retention, metabolism and removal studies.
Scope of Work and Schedule
We are providing a process for reintroduction/tracking (obj 1) and monitoring (obj 2) of mussels and water as a way to mitigate nutrients and stabilize substrates in restored urban headwaters. Project tasks organized by lead institutions in the following figure show the approach, general timeline and minimum collaborative products. Mussels and monitoring begin in year 1, experiments are conducted in summer and autumn of years 2-4 (obj 3) where a team meeting will happen in year 2 so goals towards mussel establishment and nutrient and FPOM effects can be assessed, mussels stocking assessed and possible additional mussel species added and experimented in years 3 or 4 informed by convergence meeting a possible fish management plan (objs 4-6). Modeling and scaling will occur as a collaborative exercise led by VT by the Postdoctoral Fellow starting at the end of year 2.

Additional Information on the Mussel Stocking Strategy
Nearly 35,000 mussels of six species will be propagated and released over a 5-year period from 2023 to 2027 (see table below). Mussels will be reared to >20 mm at the Freshwater Mollusk Conservation Center (FMCC), Virginia Tech, Blacksburg before stocking them at the two restoration sites in Glad and Snakeden Runs.
Mussel Propagation Target Stocking Number At Two Restoration Sites

Selected Publications
M Roznere, M Jeong, L Maechling, NK Ward, JA Brentrup, B Steele, DA Bruesewitz, HA Ewing, KC Weathers, KL Cottingham, A Quattrini Li. 2021. Towards a Reliable Heterogeneous Robotic Water Quality Monitoring System: An experimental analysis. International Symposium on Experimental Robotics https://doi.org/10.1007/978-3-030-71151-1_13
Brentrup, J.A., D.C. Richardson, C.C. Carey, N.K. Ward, D.A. Bruesewitz and K.C. Weathers. 2021. Under-ice respiration rates shift the annual carbon cycle in the mixed layer of an oligotrophic lake from autotrophy to heterotrophy. Inland Waters 11(1):114-123.
Alldred, M., Borrelli, J.J., Hoellein T., Bruesewitz D., and Zarnoch C. 2020. Marsh Plants Enhance Coastal Marsh Resilience by Changing Sediment Oxygen and Sulfide Concentrations in an Urban, Eutrophic Estuary. Estuaries and Coasts 43(4) 801-813.
Lewis, A.S., B.S. Kim, H.L. Edwards, H.L. Wander, C.M. Garfield, H.E. Murphy, N.D. Poulin, S.D. Princiotta, K.C. Rose, A.E. Taylor, K.C. Weathers, C.R. Wigdahl-Perry, K. Yokota, D.C. Richardson, D.A. Bruesewitz. Prevalence of nitrogen and phosphorus colimitation of freshwater phytoplankton explained by nitrogen deposition and lake characteristics across northeastern United States. In press at Inland Waters.
Hassett, M.C.*, Hoellein, T.J., C.B. Zarnoch, D.A. Bruesewitz, B.F. Branco, W.S. Gardner. Denitrification rates and pathways at a newly created oyster (Crassostrea virginica) reef in an urban ecosystem. In review at Estuarine, Coastal and Shelf Science.
Hoellein, T.J., C.B. Zarnoch, D.A. Bruesewitz, J. DeMartini. (2017) Contributions of freshwater mussels (Unionidae) to nutrient cycling in an urban river: Filtration, recycling, storage, and removal. Biogeochemistry 135(3):307-324. DOI 10.1007/s10533-017-0376-z
Bruesewitz, D.A., T.J. Hoellein, R. Mooney, W.S. Gardner, and E.J. Buskey (2017) Wastewater influences nitrogen dynamics in a coastal catchment during a prolonged drought. Limnology and Oceanography 62(S239-S257) DOI 10.1002/lno.10576
Gardner, W.S., S.E. Newell, M.J. McCarthy, D.K. Hoffman, K. Lu, P.J. Lavrentyev, F.L. Hellweger, S.W. Wilhelm, Z. Liu, D.A. Bruesewitz, H.W. Paerl. (2017) Community Biological Ammonium Demand: A Conceptual Model for Cyanobacteria Blooms in Eutrophic Lakes. Environmental Science and Technology 51(14):7785-7793. DOI 10.1021/acs.est.6b06296
LoTemplio, S.*, T.W. Reynolds, A. Wassie Eshete, M. Abrahams*, D.A. Bruesewitz, J.A. Wall* (2017) Ethiopian Orthodox church forests provide regulating and habitat services: evidence from stream sediment and aquatic insect analyses. African Journal of Ecology 55(2):247-251. DOI 10.1111/aje.12329
Richardson, D.C., C.C. Carey, D.A. Bruesewitz, K.C. Weathers. (2017) Intra- and inter-annual variability in metabolism in an oligotrophic lake. Aquatic Sciences 79(2):319-333. DOI 10.1007/s00027-016-0499-7
Bruesewitz, D.A., W.S. Gardner, R.F. Mooney, E.J. Buskey. (2015) Seasonal water column NH4+ cycling along a semi-arid sub-tropical river-estuary continuum: Responses to episodic events and drought conditions. Ecosystems. DOI 10.1007/s10021-015-9863-z
Bruesewitz, D.A., C. C. Carey, D.C. Richardson. (2014) Under-ice thermal stratification dynamics of a large, deep lake revealed by high frequency data. Limnology and Oceanography DOI 10.1002/lno.10014.
Bruesewitz, D.A., W.S. Gardner, R.F. Mooney, L. Pollard, E.J. Buskey. (2013) Estuarine ecosystem function response to flood and drought in a shallow, semiarid estuary: Nitrogen cycling and ecosystem metabolism. Limnology and Oceanography 58(6):2293-2309. DOI 10.4319/10.2013.58.6.2293
Hoellein, T.J., D.A. Bruesewitz, D.C. Richardson (2013) Revisiting Odum (1956): A synthesis of aquatic ecosystem metabolism. Limnology and Oceanography 58(6) 2089-2100. DOI 10.4319/lo.2013.58.6.2089
Brookes, J., K.R. O’Brien, M.A. Burford, D.A. Bruesewitz, B. R. Hodges, C.M. McBride, D.P. Hamilton (2013). Diurnal vertical mixing and stratification and effects on phytoplankton productivity in geothermal Lake Rotowhero, New Zealand. Inland Waters 3(3) 369-376. DOI 10.5268/IW-3.3.625
Solomon, C.T., D.A. Bruesewitz, D.C. Richardson, K.C. Rose, M.C. Van de Bogert, P.C. Hanson, T.K. Kratz, B. Larget, R. Adrian, B. Leroux Babin, C. Chiu, D.P. Hamilton, E.E. Gaiser, S. Hendricks, V. Istvánovics, A. Laas, D.M. O’Donnell, M.L. Pace, E. Ryder, P.A. Staehr, T. Torgersen, M.J. Vanni, K.C. Weathers, G. Zhu. (2013) Ecosystem respiration: drivers of daily variability and background respiration in lakes around the globe. Limnology and Oceanography 58(3) 849-866. DOI 10.4319/lo.2013.58.3.0849
Bruesewitz, D.A., J.L. Tank, and S.K. Hamilton. (2012) Incorporating spatial variation of nitrification and denitrification rates into whole-lake nitrogen dynamics. Journal of Geophysical Research- Biogeosciences 117. Doi 10.1029/2012JG0020006
Hoellein, T.J., D.A. Bruesewitz, and D.P. Hamilton.(2012)Are geothermal streams important sites of nutrient uptake in an agricultural and urbanizing landscape (Rotorua, New Zealand)? Freshwater Biology 57(1) 116-128. doi 10.1111/j.1365-2427.2011.02702.x
Jones, H.F.E., C.A. Pilditch, D.A. Bruesewitz, and A.M. Lohrer. (2011) Sedimentary Environment Influences the Effect of an Infaunal Suspension Feeding Bivalve on Estuarine Ecosystem Function. PLoS ONE 6(10) doi 10.1371/journal.pone.0027065.
Warneke, S., L.A. Schipper, M.G. Matiasek, K.M. Scow, S. Cameron, D.A. Bruesewitz, and I. McDonald. (2011) Nitrate removal, communities of denitrifiers and adverse effects in different carbon substrates for use in denitrification beds. Water Research 45(17) 5463-5475. doi 10.1016/j.watres.2011.08.007.
Warneke, S., L.A. Schipper, D.A. Bruesewitz, T.W. Baisden. (2011) A comparison of different approaches for measuring denitrification rates in a denitrifying bioreactor. Water Research 45: 4141-4151. DOI 10.1016/j.watres.2011.05.027
Bruesewitz, D.A., D. P. Hamilton, and L.A. Schipper. (2011) Denitrification potential of lake sediment increases across a gradient of catchment agriculture. Ecosystems 14(3):341-352. DOI 10.1007/s10021-011-9413-2
Long, L.M., L.A. Schipper, and D. A. Bruesewitz. (2011) Long-term nitrate removal in a denitrification wall. Agriculture, Ecosystems and Environment 140(2011) 514-520. DOI 10.1016/j.agee.2011.02.005
Warneke, S., L. A. Schipper, D. A. Bruesewitz, I. McDonald, and S. Cameron. (2011) Rates, controls and potential adverse effects of nitrate removal in a denitrification bed. Ecological Engineering 37(3) 511-522. DOI 10.1016/j.ecoleng.2010.12.006
Bruesewitz, D.A., J.L.Tank, S.K. Hamilton. (2009) Seasonal effects of zebra mussels on littoral nitrogen transformation rates in Gull Lake, Michigan, USA. Freshwater Biology 54(7):1427-1443. DOI 10.1111/j.1365-2427.2009.02195.x
Hamilton, S.K., D. A. Bruesewitz, G. Horst, O. Sarnelle. (2009) Biogenic calcite-phosphorus precipitation as a negative feedback to lake eutrophication. Canadian Journal of Fisheries and Aquatic Sciences 66(2): 321-342. DOI 10.1139/F09-003
Bruesewitz, D.A., J.L. Tank, and M.J. Bernot. (2008) Delineating the effects of zebra mussels (Dreissena polymorpha) on nitrogen transformation rates using laboratory mesocosms. Journal of the North American Benthological Society 27(2) 236-251. DOI 10.1899/07-031.1
Bruesewitz, D.A., J.L. Tank, M.J. Bernot, W.B Richardson and E.A. Strauss (2006) Seasonal effects of the zebra mussel (Dreissena polymorpha) on sediment denitrification rates in Pool 8 of the Upper Mississippi River. Canadian Journal of Fisheries and Aquatic Sciences 63 (5): 957-969. DOI 10.1139/F06-002