Using the past to guide future restoration: Cold-water fish habitat history of the Namekegon River, Wisconsin

The Namekagon River is part of the St. Croix National Scenic Riverway in Wisconsin, established by Congress in 1968 under the Wild and Scenic Rivers Act to protect and enhance the riverway’s outstanding natural, scenic, and recreational values. Although the scenic Namekagon River appears undisturbed from human impacts, major logging starting in the 1880’s changed the land-use and altered the benthic habitat of the river including the removal of woody cover. We have reviewed the historical fish habitat of the Namekagon River from pre-logging through present-day. Initial results suggest no significant change in river width based on surveys in the 1850’s and aerial photographs from 2005. However, photographs from the late 1800’s show bank erosion and hydrologic instability. A primary focus for managing and restoring the river is recovery of native brook trout (Salvelinus fontinalis), an important sport fish in the cold-water zone. Although brook trout were abundant in the river mainstem prior to logging, they were found only in the cold-water tributaries post-logging until naturally reproducing populations were rediscovered in the river in 1980. Results will be used by the National Park Service and Wisconsin Department of Natural Resources as a baseline to guide future restoration projects.