Nathaniel Hitt, PhD


Dr. Nathaniel (Than) P. Hitt is a Research Fish Biologist at the U.S. Geological Survey’s (USGS) Leetown Science Center in Kearneysville, West Virginia.  He holds a B.A. in Biology from the College of Wooster, an M.S. in Organismal Biology and Ecology from the University of Montana, and a Ph.D. in Fisheries and Wildlife Sciences from Virginia Tech.  Dr. Hitt’s research investigates freshwater fish ecology and community ecotoxicology from a landscape perspective, focusing on stream ecosystems in the Appalachian highlands.  His research includes:

  • Modeling fish habitat and population/community responses to environmental change
  • Forecasting effects of climate change for fish habitat in headwater streams
  • Effects of stream flow and temperature on fish communities population dynamics


Links to media coverage in The Washington PostThe Washington PostMcClatchy News, Herald-MailDiscovery, Shepherdstown Chronicle, and National Geographic News Watch

Link to Google Scholar profile

Link to Project eTrout: crowdsourcing trout ecology data with virtual reality. See a demo 360-video here.

Visit a webmap of future brook trout habitat in Catoctin Mountain Park, and see the underlying methods (2018).

Watch a National Park Service webinar "forecasting fish habitat responses to climate change: importance of groundwater-surface water interactions" (2018) 

Visit a webmap of stream-groundwater modeling results in Shenandoah National Park (2017).

Read an article announcing the Presidential Early Career Award for Scientists and Engineers (2017).

Watch a timelapse video of stream flow in Catoctin Mountain Park over a year (2016).

Watch a video of brook trout feeding in the LSC Experimental Stream Laboratory.

Watch a video introducing the LSC Experimental Stream Laboratory.

Watch a presentation on  the importance of stream network topology for brook trout recruitment in 2016. 

Watch a presentation entitled "spatial structure of stream thermal sensitivity affects climate change forecasts for brook trout" given at James Madison University in 2013.

Hear a radio segment on my work investigating brook trout responses to climate change.

Download a final report to USFWS on Kentucky arrow darter and blackside dace relations to stream conductivity.

Download a pdf of slides presented to USFWS, OSM, and TDEC regarding conductivity thresholds for abundance of imperiled stream fishes (June 9, 2015).

Watch a video citing our research on American eel responses to dam removal.

New York Times quote of the day (June 21, 2015).

Download CV


Budy, P., J. Dunham, N.P. Hitt, Y. Kanno, B. Penaluna, K.B. Rogers, and G. Thiede. In press. Distribution and status of trouts and chars in North America. Chapter 8 In: Diversity and Status of Trouts and Chars of the World. J. Kershner, J. Williams, B. Gresswell, and J. Lobon-Cervia, eds.

White, S.L., B.C. Kline, N.P. Hitt, and T. Wagner. 2019. Individual behaviour and resource use of thermally stressed brook trout Salvelinus fontinalis portend the conservation potential of thermal refugia. Journal of Fish Biology  [Link]

Pregler, K.C., R.D. Hanks, E. Childress, N.P. Hitt, D.J. Hocking, B.H. Letcher, T. Wagner, and Y. Kanno. 2019. State-space analysis of power to detect regional brook trout population trends over time. Canadian Journal of Fisheries and Aquatic Sciences [Link]

Kovach, R., J. Dunham, R. Al-Chokhachy, C. Snyder, J. Young, A. Lynch, C. Konrad, K. Jaeger, N.P. Hitt, B. Letcher, A. Rea, A. Sepulveda, G. Pederson, P. Lambert, C. Torgersen, J. Stoker, and C. Muhlfeld. 2019. An integrated framework for ecological drought across riverscapes of North America. BioScience 69:418-431 [Link]

Briggs, M.A., Z.C. Johnson, C.D. Snyder, N.P. Hitt, B.L. Kurylyk, L. Lautz, D.J. Irvine, S.T. Hurley, and J.W. Lane. 2018. Inferring watershed hydraulics and cold-water habitat persistence using multi-year air and stream temperature signals. Science of the Total Environment 636:1117-1127. [Link]

Briggs, M.A., J.W. Lane, C.D. Snyder, E.A. White, Z.C. Johnson, D.L. Nelms, and N.P. Hitt. 2018. Shallow bedrock limits groundwater seepage-based headwater climate refugia. Limnologica 68:142-156. [Link]

Hitt, N.P., Snook, E.L., and D.L. Massie. 2017. Brook trout use of thermal refugia and foraging habitat influenced by brown trout. Canadian Journal of Fisheries and Aquatic Sciences 74:406-418. [Link]

Johnson, Z.C., C.D. Snyder, and N.P. Hitt. 2017. Landform features and seasonal precipitation predict shallow groundwater influence on temperature in headwater streams. Water Resources Research 53:5788-5812. [Link]

Blazer, V.S., N.P. Hitt, C.D. Snyder, and E. Snook. 2016. Dermocystidium sp. infection in Blue Ridge Sculpin Cottus caeruleomentum captured in Maryland, USA. Journal of Aquatic Animal Health 28:143-149. [Link]

Kanno, Y., Pregler, K.C., Hitt, N.P., Letcher, B.H., Hocking, D.J., and J.E.B. Wofford. 2016. Seasonal temperature and precipitation regulate brook trout young-of-the-year abundance and population dynamics. Freshwater Biology 61:88-99. [Link]

Hitt, N.P., Floyd, M., Compton, M. and K. McDonald. 2016. Threshold responses of Blackside Dace (Chrosomus cumberlandensis) and Kentucky Arrow Darter (Etheostoma spilotum) to stream conductivity.Southeastern Naturalist 15:41-60. [Link]

Shephard, B.B., Al-Chokhachy, R., Koel, T., Kulp, M.A., and N.P. Hitt. 2016. Likely responses of native and invasive salmonid fishes to climate change in the Rocky Mountains and Appalachian mountains. Chapter 12 In: Climate Change in Wildlands. Hansen, A.J., Monahan, W.B., Theobald, D.M., and S.T. Olliff, eds. Island Press. [Link]

Snyder, C.D., Hitt, N.P., and J.A. Young. 2015. Accounting for the influence of groundwater on the thermal sensitivity of headwater streams to climate change. Ecological Applications 25:1397-1419. [Link]

Kanno, Y., Letcher, B.H., Hitt, N.P., Boughton, D.A., Wofford, J.E.B., and E.F. Zipkin. 2015. Seasonal weather patterns drive population vital rates and persistence in a stream fish. Global Change Biology 21:1856-1870. [Link]

Hitt, N.P. , Bonneau, L.K., Jayachandran, K.V. and M.P. Marchetti. 2015. Freshwater ecosystems and biodiversity. Lessons in Conservation 5:5-16. [Link]

Hitt, N.P. and D.B. Chambers. 2014. Temporal changes in taxonomic and functional diversity of fish assemblages downstream from mountaintop mining. Freshwater Science 33:915-926. [Link]

Hitt, N.P. and D.R. Smith. 2014. Threshold-dependent sample sizes for selenium assessment with stream fish tissue. Integrated Environmental Assessment and Management 11:143-149. [Link]

Jastram, J.D., Snyder, C.D., Hitt, N.P., and K.C. Rice. 2013. Synthesis and interpretation of surface-water quality and aquatic biota data collected in Shenandoah National Park, Virginia, 1979-2009. US Geological Survey, Scientific Investigations Report 2013-5157. Reston, Virginia. 77 pg. [Link]

Hitt, N.P. and J.R Roberts. 2012Hierarchical spatial structure of stream fish colonization and extinction. Oikos 121:127-137. [Link]

Iwanowicz., L.R., Blazer, V.S., Hitt, N.P., McCormick, S.D., DeVault, D., and C.A. Ottinger. 2012. Histologic, immunologic, and endrocrine biomarkers indicate contaminant effects in fishes of the Ashtabula River. Ecotoxicology 21:165-182. [Link]

Daily, J.P., Hitt, N.P., Smith, D.R., and C.D. Snyder. 2012. Experimental and environmental factors affect spurious detection of ecological thresholds. Ecology 93:17-23. [Link]

Hitt, N.P., Eyler, S., and J.E.B. Wofford. 2012. Dam removal increases American eel abundance in distant headwater streams. Transactions of the American Fisheries Society 141:1171-1179. [Link]

Smith, D.R., Snyder, C.D., Hitt, N.P., Young, J.A., and S.P. Faulkner. 2012. Shale gas development and brook trout: scaling best management practices to anticipate cumulative effects. Environmental Practice. 14:1-16. [Link]

Hitt, N.P. and P.L. Angermeier. 2011. Fish community and bioassessment responses to stream network position. Journal of the North American Benthological Society 30:296-309. [Link]

Brown, B. L., Swan, C.M., Auerbach, D., Campbell Grant, E., Hitt, N.P., Maloney, K.O., and C. Patrick. 2011. Metacommunity theory as a multi-species, multi-scale framework for studying the influence of river network structure on riverine communities and ecosystems. Journal of the North American Benthological Society 30:310-327. [Link]

Roberts, J.R. and N.P. Hitt. 2010. Longitudinal structure in stream fish communities: evaluating conceptual models with temporal data. American Fisheries Society Symposium 73: 281-299. [Link]

Betz, R., Hitt, N.P., Dymond, R., and C. D. Heatwole. 2010. A method for delineating stream network topology over large geographic extents. Journal of Spatial Hydrology 10:15-29. [Link]

Hodson, P., Reash, R., Canton, S.P., Campbell, P., Delos, C., Fairbrother, A., Hitt, N.P., Miller, L.L., and H.S. Ohlendorf. 2010. Selenium risk characterization. In: Ecological Assessment of Selenium in the Aquatic Environment. Chapman, P.M., et al., eds. Society for Ecotoxicology and Chemistry Press. [Link]

Hitt, N.P. and M. Hendryx. 2010. Ecological integrity of streams linked to human cancer mortality rates. EcoHealth 7:91-104. [Link]

Hitt, N.P. and P.L. Angermeier. 2008. River-stream connectivity affects fish bioassessment performance. Environmental Management 42:132-150. [Link]

Hitt, N.P. and P.L. Angermeier. 2008. Evidence for fish dispersal from spatial analysis of stream network topology. Journal of the North American Benthological Society 27:304-320. [Link]

Hitt, N.P. and P.L. Angermeier. 2006. Effects of adjacent streams on local fish assemblage structure in western Virginia: implications for biomonitoring. American Fisheries Society Symposium 48: 75-86.[Link]

Vignieri, S.N., Hallerman, E.M., Bergstrom, B.J., Hafner, D.J., Martin, A.P., Devers, P., Grobler, P. and N.P. Hitt. 2006. Mistaken view of taxonomy undermines conservation of an evolutionarily distinct mouse: a response to Ramey et al. Journal of Animal Conservation 9: 237-243. [Link]

Allendorf, F.W., Leary, R., Hitt, N.P., Knudsen, Boyer, M., and P. Spruell. 2005. Cutthroat Trout Hybridization and the U.S. Endangered Species Act: One Species, Two Policies. Conservation Biology 19: 1326-1328. [Link]

Hitt, N.P. and C.A. Frissell. 2004. A case study of surrogate species in aquatic conservation planning. Aquatic Conservation: Marine and Freshwater Ecosystems 14: 625-633. [Link]

Allendorf, F.W., Leary, R., Hitt, N.P., Knudsen, K., Lundquist, L., and P. Spruell. 2004. Intercrosses and the U.S. Endangered Species Act: should hybridized populations be included as westslope cutthroat trout? Conservation Biology 18: 1203-1213. [Link]

Hitt, N.P., Frissell, C.A., Muhlfeld, C.C. and F.W. Allendorf. 2003. Spread of hybridization between native westslope cutthroat trout, Oncorhynchus clarki lewisi, and non-native rainbow trout, O. mykiss.Canadian Journal of Fisheries and Aquatic Sciences 60: 1440-1451. [Link]

Hitt, N.P. 2003. Immediate effects of wildfire on stream temperature. Journal of Freshwater Ecology 18(1): 171-173. [Link]