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Influence of an Invasive Diatom Didymosphenia geminata on Food Availability and Brown Trout Energetics in Rapid Creek, South Dakota


September 2007 - June 2011


Didymosphenia geminata (hereafter referred to as ‘Didymo’) is a relatively large, easy-to-identify diatom that historically occurred in low productivity streams and lakes at northern latitudes. Since the mid-1980s, the geographic range of Didymo has expanded in many regions of Europe and North America. In many cases, these populations have taken on characteristics of an invasive species – often forming large, nuisance growths that cover stream benthos. In 2002, Didymo was reported from the Rapid Creek drainage in the Black Hills of western South Dakota. Rapid Creek represents an important brown trout Salmo trutta fishery for South Dakota, particularly below Pactola Reservoir – a reach that has long been recognized as a ‘blue ribbon’ catch-and-release fishery.

Research Products and Activities

Peer Reviewed Publications

  • James, D.A., and S.R. Chipps. 2011. The influence of Didymosphenia geminata on fisheries resources in Rapid Creek, South Dakota: An eight year history. Pages 169-175 In Conserving wild trout, R.F. Carline and C. LoSapio, editors. Proceedings of the Wild Trout X Symposium, Bozeman, Montana.
  • James, D. A., J. W. Wilhite, and S. R. Chipps. 2010. Influence of drought conditions on brown trout biomass and size structure in the Black Hills, South Dakota. North American Journal of Fisheries Management 30:791-798. Download  | 
  • James, D. A., S. H. Ranney, S. R. Chipps, and B. D. Spindler. 2010. Invertebrate composition and abundance associated with Didymosphenia geminata in a montane stream. Journal of Freshwater Ecology 25(2):235-241. Download  | 


  • James, D. A., J. W. Wilhite, and S. R. Chipps. February 24, 2009. Influence of drought conditions on brown trout Salmo trutta biomass in the Black Hills, South Dakota. Annual Meeting, Dakota Chapter, American Fisheries Society, Bismarck, North Dakota.
  • James, D. and S. Chipps. 2009. Factors associated with the distribution and abundance of Didymosphenia geminata in the Black Hills, South Dakota. Oral Presentation at the 139th Annual Meeting of the American Fisheries Society, Nashville, Tennessee.
  • James, D., K. Mosel, and S. Chipps. December 2, 2009. Influence of light availability on Didymosphenia geminata in a montane stream. 70th Annual Midwest Fish and Wildlife Conference, Springfield, Illinois.
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Current Staff

Federal Staff: 95

Masters Students: 238

Phd Students: 144

Post Docs: 54

University Staff: 239

5 Year Summary

Students graduated: 673

Scientific Publications: 1905

Presentations: 4236



Funding Agencies

  • South Dakota Department of Game, Fish and Parks


Cooperative Research Units Program Headquarters Cooperators

  1. U.S. Geological Survey