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Lesley Knoll

Station Biologist and Adjunct Assistant Professor


Itasca Biological Station and Laboratories

Research statement

Many of my research questions focus on understanding how global change, specifically land use change and climate change, acts alone or in combination to regulate aquatic function (e.g., primary production, carbon and nutrient fluxes, anoxia) and structure (e.g., phytoplankton composition). My background is broad, and I have also addressed questions related to aquatic invasive species, animal-mediated nutrient cycling, toxic cyanobacteria, and ecological stoichiometry. I approach my projects by using large-scale surveys, long-term datasets, field and lab experiments, and advanced aquatic sensors including with the Global Lake Ecological Observatory Network (GLEON). 


Knoll, L.B., C.E. Williamson, R.M. Pilla, T.H. Leach, J.A. Brentrup, and T.J. Fisher. 2018. Browning-related oxygen depletion in an oligotrophic lake. Inland Waters: doi: 10.1080/20442041.2018.1452355.

Pilla, R.M., C.E. Williamson, J. Zhang, R.L. Smyth, J.D. Lenters, J.A. Brentrup, L.B. Knoll, and T.J. Fisher. 2018. Long-term trends in water temperature and thermal stratification in two small lakes resulting from browning-related decreases in water transparency. Journal of Geophysical Research: Biogeosciences: 123. doi: 10.1029/2017JG004321. 

Knoll, L.B. and J.B. Cotner. 2018. University of Minnesota Itasca Biological Station and Laboratories: Over 100 years of field-based education and research. Limnology and Oceanography Bulletin 27: 42-44. DOI: 10.1002/lob.10232 

Richardson, D.C., S.J. Melles, R.M. Pilla, A.L. Hetherington, L.B. Knoll, C.E. Williamson, B.M. Kraemer, J.R. Jackson, E.C. Long, K. Moore, L.G. Rudstam, J.A. Rusak, J.E. Saros, S. Sharma, K.E. Strock, K.C. Weathers, and C.R. Wigdahl-Perry. 2017. Transparency, geomorphology, and mixing regime explain variability in trends in lake temperature and stratification across northeastern North America (1975 – 2014). Water 9: 442. doi:10.3390/w9060442 

Knoll, L.B., A. Morgan, M.J. Vanni, T.H. Leach, T.J. Williamson, and J.A. Brentrup. 2016. Quantifying pelagic phosphorus regeneration using three methods in lakes of varying productivity. Inland Waters 6: 509-522. 

Brentrup J.A., C.E. Williamson, W. Colom-Montero, W. Eckert, E. de Eyto, H.P. Grossart, Y. Huot, P. Isles, L.B. Knoll, T.H. Leach, C.G. McBride, D. Pierson, F. Pomati, J.S. Read, K.C. Rose, N.R. Samal, P.A. Stæhr, and L. A. Winslow. 2016. The potential of high-frequency profiling to assess vertical and seasonal patterns of phytoplankton dynamics in lakes: An extension of the Plankton Ecology Group (PEG) model. Inland Waters​: 565-580. 

Williamson, C.E., E.P. Overholt, R.M. Pilla, T.H. Leach, J.A. Brentrup, L.B. Knoll, E.M. Mette, and R.E. Moeller. 2015. Ecological consequences of long-term browning in lakes. Scientific Reports 5: 18666. doi:10.1038/srep18666. 

Knoll, L.B., E.J. Hagenbuch, M.H. Stevens, M.J. Vanni, W.H. Renwick, J.C. Denlinger, R.S. Hale, and M.J. González. 2015. Predicting eutrophication status in reservoirs at large spatial scales using landscape and morphometric variables. Inland Waters 5: 203-214. 

Baustian, M.M., G.J.A. Hansen, A. de Kluiver, K. Robinson, E.N. Henry, L.B. Knoll, K.C. Rose, and C.C. Carey. 2014. Linking the bottom to the top in aquatic ecosystems: mechanisms and stressors of benthic-pelagic coupling. p. 25-47. In P.F. Kemp [ed.], Eco-DAS X Symposium Proceedings. ASLO. doi:10.4319/ecodas.2014.978-0-9845591-4-5.25 

Knoll, L.B., M.J. Vanni, W.H. Renwick, and S. Kollie. 2014. Burial rates and stoichiometry of sedimentary carbon, nitrogen and phosphorus in Midwestern US reservoirs. Freshwater Biology 59: 2342-2353. 

Williamson, C.E., J.A. Brentrup, J. Zhang, W.H. Renwick, B.R. Hargreaves, L.B. Knoll, E.P. Overholt, and K.C. Rose. 2014. Lakes as sensors in the landscape: Optical metrics as scalable sentinel responses to climate change. Limnology and Oceanography 59: 840-850. 

Knoll, L.B., M.J. Vanni, W.H. Renwick, E.K. Dittman, and J.A. Gephart. 2013. Temperate reservoirs are large carbon sinks and small CO2 sources: Results from high-resolution carbon budgets. Global Biogeochemical Cycles 27: 52-64. 

White, J.D., R.B. Kaul, L.B. Knoll, A.E. Wilson, and O. Sarnelle. 2011. Large variation in vulnerability to grazing within a population of the colonial phytoplankter, Microcystis aeruginosa. Limnology and Oceanography 56: 1714-1724. 

Kissman, C.E.H., L.B. Knoll, and O. Sarnelle. 2010. Dreissenid mussels (Dreissena polymorpha and Dreissena bugensis) reduce microzooplankton and macrozooplankton biomass in thermally stratified lakes. Limnology and Oceanography 55: 1851-1859. 

González, M.J., L.B. Knoll, and M.J. Vanni. 2010. Differential effects of elevated nutrient and sediment inputs on survival, growth and biomass of a common larval fish species. Freshwater Biology 55: 654-669. 

Tranvik, L.J., J.A. Downing, J.B. Cotner, S.A. Loiselle, R.G. Striegl, T.J. Ballatore, P. Dillon, K. Finlay, K. Fortino, L.B. Knoll, P.L. Kortelainen, T. Kutser, S. Larsen, I. Laurion, D.M. Leech, S.L. McCallister, D.M. McKnight, J.M. Melack, E. Overholt, J.A. Porter, Y. Prairie, W.H. Renwick, F. Roland, B.S. Sherman, D.W. Schindler, S. Sobek, A. Tremblay, M.J. Vanni, A.M Verschoor, E. von Wachenfeldt, and G.A. Weyhenmeyer. 2009. Lakes and reservoirs as regulators of carbon cycling and climate. Limnology and Oceanography 54: 2298-2314. 

Knoll, L.B., P.B. McIntyre, M.J. Vanni, and A.S. Flecker. 2009. Feedbacks of consumer nutrient recycling on producer biomass and stoichiometry: separating direct and indirect effect. Oikos 118: 1732-1742. 

Knoll, L.B., O. Sarnelle, S.K. Hamilton, C.E.H. Kissman, A.E. Wilson, J.B. Rose, and M.R. Morgan. 2008. Invasive zebra mussels (Dreissena polymorpha) increase cyanobacterial toxin concentrations in low-nutrient lakes. Canadian Journal of Fisheries and Aquatic Sciences 65: 448-455. 

Vanni M.J., A.M. Bowling, E.M. Dickman, R.S. Hale, K.A. Higgins, M.J. Horgan, L.B. Knoll, W.H. Renwick, and R.A. Stein. 2006. Nutrient cycling by fish supports relatively more primary production as lake productivity increases. Ecology 87: 1696-1709. 

Sarnelle, O., A.E. Wilson, S.K. Hamilton, L.B. Knoll, and D.F. Raikow. 2005. Complex interactions between the zebra mussel, Dreissena polymorpha and the harmful phytoplankton, Microcystis aeruginosa. Limnology and Oceanography 50: 896-904. 

Knoll, L.B., M.J. Vanni, and W.H. Renwick. 2003. Phytoplankton primary productivity and photosynthetic parameters in reservoirs along a gradient of watershed land use. Limnology and Oceanography 48: 608-617. 


Ph.D. in Ecology, Evolution, and Environmental Biology, Miami University 
M.S. in Fisheries and Wildlife, Michigan State University 
B.S. in Botany, Miami University 

218-699-3550 (ext. 3345)

Itasca Station
28131 University Circle
Lake Itasca, MN 56470