Managing Expectations from Intensively Monitored Watershed Studies

Abstract

AbstractIntensively monitored watershed (IMW) studies, the intent of which is to quantify habitat restoration effects on salmonid populations, have been underway in the Pacific Northwest, USA, for more than two decades. Lack of population‐level response to habitat improvements by target species in some IMWs may be related to incomplete knowledge of factors regulating fish abundance, excessively prolonged restoration application periods, underappreciation of natural environmental and population variability, failure to carry out restoration at a sufficiently large scale within a watershed, lack of sufficient time to document a posttreatment response, or an actual failure of the restoration activities in those locations to achieve population recovery objectives. However, knowledge gained from IMWs has yielded important insight into (1) the long‐term responses of salmon and steelhead Oncorhynchus mykiss to different types of restoration and (2) the importance of placing freshwater habitat improvements in the context of changes in anadromous salmonid survival and growth during other life history stages. Scientists, funding organizations, and policymakers should appreciate the potential value of IMWs as long‐term barometers of the status of salmon populations and their habitats in watersheds where restoration activities are occurring. This requires a commitment to prolonged monitoring and an acknowledgment that environmental recovery after habitat restoration may take decades.