Aquatic ecology, focused on:

• Community and ecosystem ecology of shallow lakes and wetlands.
• Role of food-web interactions in the alternative stable state model for shallow lakes. 
• Ecology of fish, aquatic invertebrates, and submerged macrophytes.
• Biotic and abiotic factors responsible for the structure of aquatic food webs.
• Biotic influences on species diversity in shallow lakes.
• Stoichiometric relationships in aquatic habitats.
• Modeling aquatic ecosystems and processes, biometry.

• 2010-2013.  Quantifying Carbon Burial in Healthy Minnesota Wetlands. Funded by the Minnesota LCCMR (with J. Cotner). 
• 2010-2012.  Developing Sustainable and Cost-Effective Approaches to Conservation and Management of Shallow Lakes in Minnesota.  Funded by the Minnesota LCCMR (with J. Cotner, B. Herwig, and M. Hanson).
• 2009-2012.  Collaborative Research (RUI): Burial of organic carbon in temperate, shallow lakes.   Funded by the National Science Foundation (with K. Theissen, J. Cotner, J. Ramstack,  and M. Edlund).
  

Other Recent Projects

• Stoichiometric relationships in shallow prairie lakes and their response to state shifts. 
• Fish excretion as a source of internal nutrient loading in shallow prairie lakes (with B. Herwig (MN DNR) and L. Laurich (MU)).
• Prey consumption and population dynamics of fathead minnows in prairie wetlands (with B. Herwig (MN DNR)).
• Relationships among diet, growth rate, body size, and concentrations of carbon, nitrogen, and phosphorus in walleye (with D. Willis and M. Ward (SDSU).  

(undergraduate authors are underlined)

• Friederichs, S.J., K.D. Zimmer, B.R. Herwig, M.A. Hanson, and J.R. Fieberg. In press. Total phosphorus and piscivore mass as drivers of food web characteristics in shallow lakes. Oikos.
• Herwig, B.R., K.D. Zimmer, M.A. Hanson, M.L. Konsti, J.A. Younk, R.W. Wright, S.R. Vaughn, and M.D. Haustein. 2010.  Factors influencing fish distributions in shallow lakes in prairie and prairie-parkland regions of Minnesota, USA.  Wetlands 30:600-619.Zimmer, K.D., M.A. Hanson,
• B.R. Herwig, and M.L. Konsti. 2009. Thresholds and stability of alternative regimes in shallow prairie-parkland lakes of central North America. Ecosystems 12:843-852.  
• Potthoff, A.J., B.R. Herwig, M.A. Hanson, K.D. Zimmer, M.G. Butler, J.R. Reed, B.G. Parson, M.C. Ward, and D.W. Willis. 2008. Cascading food web effects of piscivore introductions in shallow lakes. Journal of Applied Ecology 45:1170-1179.
• Verant, M.L., M.L. Konsti, K.D. Zimmer, and C.A. Deans. 2007. Factors influencing nitrogen and phosphorus excretion rates by fish in a shallow lake. Freshwater Biology 52:1968-1981.
• Herwig, B.R., and K.D. Zimmer.  2007. Population dynamics and prey consumption by fathead minnows in prairie wetlands: importance of detritus and larval fish. Ecology of Freshwater Fish 16:282-294.
• Hood J.M., S. Brovold, R.W. Sterner,  M. Villar-Argaiz, K.D. Zimmer. 2006. Near infrared spectrophotometry (NIRS) for the analysis of seston carbon, nitrogen, and phosphorus from diverse sources. Limnology and Oceanography Methods 4:96-104.  
• Scheffer, M., G.J. van Geest, K.D. Zimmer, E. Jeppesen, M.G. Butler, M.A. Hanson, M. Søndergaard, S. Declerck, and L. De Meester. 2006. Small habitat size and isolation can promote species richness: second-order effects on biodiversity in shallow lakes and ponds. Oikos 112:227-231.
• Zimmer, K.D., B.H. Herwig, and L.M. Laurich. 2006. Nutrient excretion by fish in wetland ecosystems and its potential to support algal production. Limnology and Oceanography 51:197-207.  
• Hanson, M.A., K.D. Zimmer, M.G. Butler, B.A. Tangen, B.H. Herwig, and N.H. Euliss. 2005. Biotic interactions as determinants of ecosystem structure in prairie wetlands: an example using fish.Wetlands 25:764-775.
• Herwig, B.R., M.A. Hanson, J.R. Reed, B.G. Parsons, A.J. Pothoff, M.C. Ward, K.D. Zimmer, M.G. Butler, D.W. Willis, and V.A. Snook. 2004. Walleye stocking as a tool to suppress fathead minnows and improve habitat quality in semipermanent and permanent wetlands in the prairie pothole region of Minnesota. Minnesota Department of Natural Resources Special Publication Number 159.
• Angeler, D.G., P. Chow-Fraser, M.A. Hanson, S. Sánchez-Carillo, and K.D. Zimmer. 2003.  Biomanipulation: a useful tool for freshwater wetland mitigation? Freshwater Biology 48:2203-2213.
• Laurich, L.M., K.D. Zimmer, M.G. Butler, and M.A. Hanson. 2003. Selectivity for zooplankton prey by fathead minnows and brook sticklebacks. Wetlands 23:416-422.
• Zimmer, K.D., M.A. Hanson, and M.G. Butler. 2003. Interspecies relationships, community structure, and factors influencing the abundance of submerged macrophytes in prairie wetlands. Wetlands:717-728. 
• Zimmer, K.D., M.A. Hanson, and M.G. Butler. 2003. Relationships among nutrients, phytoplankton, macrophytes, and fish in prairie wetlands. Canadian Journal of Fisheries and Aquatic Sciences 60:721-730.
• Zimmer, K.D., M.A. Hanson, and M.G. Butler. 2002. Effects of fathead minnows and restoration on prairie wetland ecosystems. Freshwater Biology 47:2071-2086.
• Melaas, C.L., K.D. Zimmer, M.G. Butler, and M.A. Hanson. 2001. Effects of rotenone on aquatic invertebrate communities in prairie wetlands. Hydrobiologia 459:177-186.
• Muscha, M.J., K.D. Zimmer, M.G. Butler, and M.A. Hanson. 2001. A comparison of horizontally and vertically deployed aquatic invertebrate activity traps. Wetlands 21:301-307.
• Zimmer, K.D., M.A. Hanson, M.G. Butler, and W.G. Duffy. 2001. Size distributions of aquatic invertebrates in two prairie wetlands, with and without fish, with implications for community production. Freshwater Biology 46:1373-1386.
• Zimmer, K.D., M.A. Hanson, and M.G. Butler. 2001. Effects of fathead minnow colonization and removal on a prairie wetland ecosystem. Ecosystems 4:346-357.
• Zimmer, K.D., M.G. Butler, M.A. Hanson, and W.G. Duffy. 2001. Influences of fathead minnows and aquatic macrophytes on nutrient partitioning and ecosystem structure in two prairie wetlands. Archiv für Hydrobiologie 150:411-433.
• Hanson, M.A., C.C. Roy, N.H. Euliss, K.D. Zimmer, M.R. Riggs, and M.G. Butler. 2000. A surface-associated activity trap for capturing water-surface and aquatic invertebrates in wetlands. Wetlands 20:205-212.
• Zimmer, K.D., M.A. Hanson, and M.G. Butler. 2000. Factors influencing invertebrate communities in prairie wetlands: a multivariate approach. Canadian Journal of Fisheries and Aquatic Sciences 57:76-85.
• Noraker, T.D., K.D. Zimmer, M.G. Butler, and M.A. Hanson. 1999. Dispersion and distribution of marked fathead minnows (Pimephales promelas) in prairie wetlands. Journal of Freshwater Ecology 14:287-292.
• Wang, L.I., K.D. Zimmer, P.A. Diedrich, and S.F. Williams. 1996. The two-story rainbow trout fishery and its effect on the zooplankton community in a Minnesota lake. Journal of Freshwater Ecology 11:67-80.
  

Lab Members 2010-11

Postdoctoral Associates

• Leah Domine
• Will Hobbs

Undergraduate Research Assistants

• Ann Goding
• Ariel Gittens
• Dan Probst
• Jordan Goetting
• Liz McHale
• Luke Ginger
• Rachel Rockwell
• Tom Langer
• Vinney Floder
• Luke Nolby
• Charles Bruchu

Student Researchers, Summer 2010

• Elisabeth McHale
• Dustin Potter
• Jordan Goetting
• Charles Bruchu
• Vincent Floeder
• Ann Goding
• Dan Probst
• Luke Ginger
• Luke Nolby
• Tom Langer
• Adam Johannsen
• Rachel Rockwell
• Ariel Gittens (from Concordia, former McNair Scholar) 

Previous Student Researchers

• Mikkel Haugen
• Adam Johannsen
• Kristine Maurer
• Dustin Potter
• Heidi Telste
• Patti Gamboni
• Luke Schroeder
• Matt Gorman
• Sam Friederichs
• Rian Cleary
• Sarah Derr
• Krista Damme
• John Balk
• Mitch Haustein
• Melissa Konsti
• MattGorman
• Patti Gamboni
• Michelle Verant
• Luke Schroeder