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Brent C. Knights

Position title: Research Fishery Biologist

Email: bknights@usgs.gov
Phone: 608.781.6332
Fax: 608.783.6066

Education:
1991 B.S., Fisheries and Wildlife Biology, Iowa State University
1993 M.S., Biology (Aquatic Sciences), University of Wisconsin- La Crosse

Primary Activities:
Our River Productivity Team focuses on understanding production and diversity of aquatic organisms and supporting processes in large floodplain rivers to inform management and restoration.  My research is concentrated on how the abundance, size structure, food web and nutritional health (lipid and fatty acid markers) of fishes vary across gradients of hydrology, geomorphology, water chemistry, aquatic vegetation and invasive species abundance in the Upper Mississippi and Illinois River system.  This research includes comparative surveys and experiments in the field, and analyses of long-term monitoring data.

Research Interests:

• Floodplain river ecosystems and restoration
• Production and diversity of fishes
• Aquatic food webs
• Aquatic invasive species
• Threatened or endangered fishes

Active Projects:

• Identification of controls on biological productivity in large rivers using lipid, fatty acid and isotopic markers (River Productivity Team)
• Identifying potential controls on the abundance and size structure of centrarchids and diversity of fishes in off-channel areas in the Upper Mississippi River System using GIS and long term monitoring data (River Productivity Team)
• Association between fish assemblage and off-channel area type in the impounded reach of the Upper Mississippi and Illinois rivers (River Productivity Team)
• High-resolution acoustic imaging technology to identify factors limiting fishes of the UMRS (River Productivity Team)

Select Publications:
Knights, B.C.  2007.  Identifying potential controls on the abundance and size structure of centrarchids and diversity of fishes in off-channel areas in the Upper Mississippi River System:  Aquatic vegetation and physical features.  Completion report for the U.S. Army Corps of Engineers, Rock Island District.  U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin, July 2007.  108pp.

Gutreuter, S., J. M. Vallazza, and B. C. Knights.  2006.  Persistent Disturbance by Commercial Navigation Alters the Relative Abundance of Channel-Dwelling Fishes in a Large River. Canadian Journal of Fisheries and Aquatic Sciences 63(11):2418-33.

Wiener, J. G., B. C. Knights, M. B. Sandheinrich, J. D. Jeremiason, M. E. Brigham, D. R. Engstrom, L. G. Woodruff, W. F. Cannon, and S. J. Balogh.  2006.  Mercury in Soils, Lakes, and Fish in Voyageurs National Park (Minnesota): Importance of Atmospheric Deposition and Ecosystem Factors. Environmental Science & Technology 40(20):6261-68.

Knights, B.C., J.H. Wlosinski, J.A. Kalas, and S.W. Bailey.  2003.  Upstream fish-passage opportunities at Ohio River mainstem dams. Completion report for the U.S. Army Corps of Engineers, Nashville District.  U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin. 96 pp + Appendixes A‑B.

Knights, B. C.,  J. M. Vallazza, S. J. Zigler, and M. R. Dewey.  2002.  Habitat and movement of lake sturgeon in the Upper Mississippi River system, USA. Transactions of the American Fisheries Society 131:507-522. 

Links:
Managing Pathways of Biological Production in Large-River Ecosystems

Habitat use and movement of lake sturgeon (Acipenser fulvescens) in the Upper Mississippi River: effects of navigation

Assessment of the biological effects of the Finger Lakes Habitat Rehabilitation and Enhancement Project: Responses of fish and aquatic invertebrates

The Limnology and Ecology of Off-channel Areas in the Upper Mississippi River System

Fish passage bibliography

Movement and habitat use of paddlefish in the Upper Mississippi River and tributaries

Fishery Resources of Deep Channels of the Upper Mississippi River System

Identification of ecosystem factors affecting methylmercury contamination of food webs in semi-remote lakes of the Voyageurs National Park

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