Salmonid Spawning Habitat in Rivers: Physical Controls, Biological Responses, and Approaches to Remediation
Spawning Habitat Remediation as Part of National and Regional Scale Programs to Recover Declining Salmonid Populations
Jill A. Marshall, Paul DeVries, and Nigel Milner
Salmonid habitat restoration efforts have relatively recently become part of larger scale programs that attempt to address new thinking and concerns about ecosystem function and strategic allocation of effort (e.g., Williams et al. 1997; Wissmar and Bisson 2003). Historically, the majority of efforts to restore salmonid spawning and other habitats have been directed at small-scale, individual projects with relatively little coordination within or between watersheds. The patchwork of projects within a watershed reflected available funding, local interest and expertise, and legislative time scales. With the continuing declines in salmonid populations in many regions both in the United States and United Kingdom, and the increased awareness of social, esthetic, economic, and regulatory issues, considerable (and increasing) amounts of money have been spent to restore salmonid habitat at ever-increasing scales. As the restoration community wrestles with the technical challenge of identifying and validating effective measures for restoring or improving habitat for salmon and trout, let alone defining clearly in practical terms what it really means to restore natural ecological and channel processes, numerous programs and conceptual frameworks for doing so have arisen over the past decade or two that have involved implementing restoration efforts at ever-increasing scales.