Scientists & Staff

Dr. Anne Timm getting ready to light trap larval northern pike.

Anne Timm

Research Aquatic Ecologist
5523 Research Park Drive; Suite 350
Suite 350
Baltimore, MD, 21228
Phone: 443-543-5385

Contact Anne Timm

Current Research

My current research program focuses on understanding how changes in land use and environmental condition affect aquatic ecosystems and associated aquatic species populations. I am lead investigator on a research project that investigates effects of water level change on northern pike spawning and nursery habitat in Rainy Lake/Namakan Reservoir, Minnesota. I am also working on a team of research scientists to quantify biological structural and functional parameters associated with stream simulation culvert designs on National Forests of the Great Lakes. Currest and future research will also focus on stream temperature change effects resulting from climate change on coldwater trout communities of northeastern Wisconsin. I recently transferred from the Northern Research Station, Grand Rapids, Minnesota office to the Baltimore Field Station to join the team of scientists working at Urban Field Stations. I started a project in collaboration with University of Maryland, Baltimore County, Center for Urban Environmental Research and Education and Department of Chemical Engineering on pharmaceuticals and personal care chemical (PPCPs) effects on aquatic species in the Patapsco River Watershed. This watershed is the Urban Waters Federal Partnership urban watershed for Baltimore, Maryland.

Research Interests


· Effects of water level change and flow variability resulting from land use and climate change on aquatic species

· Evaluating effectiveness of stream restoration on aquatic habitats

· Biological processing of pharmaceuticals and personal care chemicals (PPCPs) in aquatic ecosystems

· Genetic approaches at the landscape scale for fish population management

Past Research

Genetic effects of brook trout dispersal barriers in relation to height.

We screened variation at eight microsatellite DNA loci within and among brook trout Salvelinus fontinalis populations above and below putative natural barriers ranging in height from 1.4 to 61 meters in 10 streams, quantifying allelic variation, differentiation (FST) above and below a barrier, individual assignment probability (Q) above or below a barrier, and individual relatedness (rxy) on either side or across a barrier. Significant relationships were identified between barrier height and FST, ln likelihood of individual assignment, mean relatedness, rxy, and mean number of full-sibs per family group. Results indicated the occurrence of genetically effective dispersal in S. fontinalis across higher barriers than the previously documented 0.74-m.

Anuran habitat use on abandoned and reclaimed mining areas of Southwestern Indiana.

We surveyed wetland habitats on abandoned and reclaimed strip mines in southwestern Indiana to determine species richness and species-habitat relations of anurans at 40 wetland sites during the 2000 breeding season. Nine anuran species were detected, including the state-endangered crawfish frog (Rana areolata). Reproduction was confirmed for seven species, and evidence of breeding was detected at all wetland types, both abandoned and reclaimed. Bullfrogs Rana catesbeiana, green frogs Rana clamitans, and Blanchard's cricket frogs Acris crepitans blanchardi showed preferences for open water habitats relative to ephemeral wetlands. Metamorphs of spring peeper Pseudacris crucifer, southern leopard frog Rana sphenocephala, Fowler's toad Bufo fowleri, Fowler's toad Bufo fowleri, Cope's gray treefrog Hyla chrsoscelis, and bullfrog were observed at sediment basin and ephemeral site types. Post-mining landscapes provide opportunity to restore ephemeral habitats and grassland habitats; both are declining due to human land use, and both provide habitat for anurans. Topographic and vegetative heterogeneity on once-mined lands may provide a sufficiently diverse landscape to support the full range of anuran species in the area.

Why This Research is Important

Assessing aquatic vegetation as habitat for larval and young-of-the-year northern pike: Results of this research will inform managers about tradeoffs between regulated water levels and fish spawning success. Our team produced a submerged aquatic vegetation model that can be used to compare availability of northern pike spawning habitats in large reservoir systems in different water level conditions due to water level regulation and climate change effects.

Fish habitat and biomass at stream simulation culverts of the Great Lakes: The stream simulation approach to road-stream crossing design is an important restoration technique that maintains similar structural characteristics of the natural stream channel. No current studies have evaluated stream simulation design culverts for both structural habitat and biological processes needed for aquatic species to persist. Our objectives were to determine effectiveness of stream simulation design for improving physical habitat and biological function of fish (biomass, g/m3).

Bioaccumulation of PPCPs in crayfish of the Gwynns Falls watershed: The presence of pharmaceutical and personal care products (PPCPs) in water and bottom sediments can alter functions of aquatic organisms and accumulate in tissues. Objectives of this project are to identify locations where crayfish are exposed to PPCPs and to investigate how PPCPs are partitioned in the aquatic environment of the Dead Run subwatershed. Dead Run is in the Gwynns Falls watershed that drains into the Chesapeake Bay where personal care products are emerging chemicals of concern.


  • Virginia Polytechnic Institute and State University, Ph.D. Fisheries and Wildlife, 2011
  • Indiana University, Environmental Science Aquatic Habitat Analysis Environmental Science, Aquatic Habitats, 2000
  • Luther College, B.A. Biology, 1996

Professional Experience

  • Aquatic Ecologist, USDA Forest Service, Hoosier National Forest, Tell City, Indiana 2002 - 2005
  • Environmental Scientist, Hayes, Seay, Mattern, and Mattern, Inc., Raleigh, North Carolina 2000 - 2002
  • Secondary Education Science and Biology Teacher, United States Peace Corps 1994 - 1996

Professional Organizations

  • American Fisheries Society
  • North American Native Fishes Association
  • American Society of Ichthyology and Herpetology
  • Graduate Women in Science

Publications & Products

Last modified: Tuesday, August 05, 2014