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Influence of fish density on growth rate of brown trout in Spearfish Creek, South Dakota


July 2016 - December 2018


Growth rate of Brown Trout is known to be density-dependent in stream systems. In Spearfish Creek, South Dakota, recent work has shown that mean biomass of Brown Trout >200 mm is about three times greater than that in Castle or Rapid creeks (James and Chipps 2016). However, adult Brown Trout in Spearfish Creek are about 30% smaller (220 mm) than similarly aged fish in Rapid Creek (315 mm; James and Chipps 2016). Because angler harvest of Brown Trout is generally low in Spearfish Creek (Simpson 2011), management options for increasing the size structure of the trout population may be limited. Catch and release regulations, for example, would exacerbate problems with small size of adult fish when growth rate is density-dependent; in contrast, liberalized regulations may have limited effect due to low angler harvest and(or) the social stigma associated with harvesting naturalized trout. From a management perspective, experimental manipulation of Brown Trout abundance shows promise as an approach for increasing the growth rate of stream-dwelling trout. The purpose of this project is to evaluate the growth response of Brown Trout to localized reductions of fish density in Spearfish Creek. This study addresses Issues 6 and 8 of the Spearfish Creek watershed plan and is in support of Objectives 3 and 4 of that plan. Additionally, this study addresses issues 3, 14, and 28 of the Black Hills Fisheries Management Area Strategic Plan (2014-2018) and is in support of Objective 8 of that plan.


Current Staff

Federal Staff: 101

Masters Students: 234

Phd Students: 160

Post Docs: 60

University Staff: 268

5 Year Summary

Students graduated: 671

Scientific Publications: 1868

Presentations: 4326



Funding Agencies

  • South Dakota Game, Fish & Parks


Cooperative Research Units Program Headquarters Cooperators

  1. U.S. Geological Survey