The Effects of Lunker Structures on Brook Trout and Brown Trout Abundances in Rosenow Creek, Wisconsin
Numbers of brook trout, a salmonid species native to Wisconsin, have been declining in recent years. Although the mechanism of their disappearance has not yet been proven, it is suspected that the introduction of brown trout to streams previously occupied only by brook trout is having a major impact. We hypothesized that brown trout were displacing brook trout in optimal stream habitat. Rosenow Creek was chosen as a study site on account of its being divided into a section of artificial habitat, characterized by lunker structures, and a section of natural habitat. Fish abundances and stream habitat were studied. Brown trout were found to occupy optimal stream areas of high velocity and high undercut area, while brook trout occupied marginal upstream areas of low velocity.
v, 24 p.
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder.