Watershed Restoration: Principles and Practices

Chapter 20: Fish Habitat Restoration in the Pacific Northwest: Fish Creek of Oregon

G. H. Reeves, D. B. Hohler, B. E. Hansen, F. H. Everest, J. R. Sedell, T. L. Hickman, and D. Shively

doi: https://doi.org/10.47886/9781888569049.ch20

The decline of anadromous salmonids in the Pacific Northwest of the United States is attributable to a suite of factors that includes overexploitation in sport and commercial fisheries, habitat alteration, migration barriers, variable ocean conditions, and influence of hatchery practices (Nehlsen et al. 1991). A combination of these factors is generally associated with the depressed status of almost every population. The factor most associated with the decline of individual populations is habitat alteration, which includes a decline in the quantity and quality of freshwater habitat (Nehlsen et al. 1991).

Habitat in streams used by anadromous salmonids in the Pacific Northwest has been simplified as a consequence of many human activities (Hicks et al. 1991b; Sisson et al. 1992). Simplification includes the loss of habitat, quality, diversity, and complexity. Such changes have occurred as a result of past as well as more recent activities and are common throughout much of the range of anadromous salmonids in western North America (Sedell and Luchessa 1982; Hicks et al. 1991b). Lawson (1993) argued that the arrest and reversal of the continuing decline of the quantity and quality of freshwater habitat are imperative if populations of anadromous salmonids are to be protected from further decline or local extinction.