Phil Roni

Global Review of the Physical and Biological Effectiveness of Stream Habitat Rehabilitation Techniques

Abstract The degradation of inland aquatic habitats caused by decades of human activities has led to worldwide efforts to rehabilitate freshwater habitats for fisheries and aquatic resources. We reviewed published evaluations of stream rehabilitation techniques from throughout the world, including studies on road improvement, riparian rehabilitation, floodplain connectivity and rehabilitation, instream habitat improvement, nutrient addition, and other, less-common techniques. We summarize current knowledge about the effectiveness of these techniques for improving physical habitat and water quality and increasing fish and biotic production. Despite locating 345 studies on effectiveness of stream rehabilitation, firm conclusions about many specific techniques were difficult to make because of the limited information provided on physical habitat, water quality, and biota and because of the short duration and limited scope of most published evaluations. Reconnection of isolated habitats, floodplain rehabilita...

Progress and Challenges of Testing the Effectiveness of Stream Restoration in the Pacific Northwest Using Intensively Monitored Watersheds

Across the Pacific Northwest, at least 17 intensively monitored watershed projects have been implemented to test the effectiveness of a broad range of stream restoration actions for increasing the freshwater production of salmon and steelhead and to better understand fish–habitat relationships. We assess the scope and status of these projects and report on challenges implementing them. We suggest that all intensively monitored watersheds should contain key elements based on sound experimental design concepts and be implemented within an adaptive management framework to maximize learning. The most significant challenges reported by groups were (1) improving coordination between funders, restoration groups, and researchers so that restoration and monitoring actions occur based on the project design and (2) maintaining consistent funding to conduct annual monitoring and evaluation of data. However, we conclude that despite these challenges, the intensively monitored watershed approach is the most reliable me...

More Sites or More Years? Optimal Study Design for Monitoring Fish Response to Watershed Restoration

Abstract Every year in the Pacific Northwest, hundreds of stream restoration projects are implemented at great expense in the hope that they will increase salmonid abundance. Our understanding of how salmonids interact with their freshwater habitat has steadily improved, but we are still a long way from being able to reliably predict population-level effects of individual projects. To determine whether these projects are in fact increasing salmonid abundance, we will need to implement restoration at the watershed scale, monitor the populations after the freshwater portion of their life history is completed, and replicate the experiment across multiple watersheds to produce results that can be generalized. Although there has been some progress in this direction, it has largely consisted of independent efforts at a relatively small scale. In this paper, we use smolt counts of coho salmon Oncorhynchus kisutch from streams in western Washington and Oregon, along with approximate restoration and monitoring cos...

Coho Salmon Smolt Production from Constructed and Natural Floodplain Habitats

Abstract We examined existing smolt trapping data from 30 constructed and natural floodplain habitats to determine whether the number (production), density, and length of coho salmon Oncorhynchus kisutch smolts varied by project type and area. At 13 of the 30 sites we conducted detailed physical surveys to examine how morphology (shoreline irregularity), depth, and cover influenced smolt density and length. Mean smolt production for all sites averaged 2,492, density 0.37 smolts/m2, and length 98.9 mm. We found no significant difference in smolt production or density between natural and constructed sites or among project types. Smolt length differed by project type and morphology, excavated ponds (gravel pits and mill ponds) producing significantly larger smolts than constructed groundwater or natural channels. Smolt production was positively correlated with wetted area. Smolt length was negatively correlated with density and distance from salt water, suggesting that sites further inland with cooler water ...

Fall and Spring Emigration Timing of Juvenile Coho Salmon from East Twin River, Washington

Abstract We implanted 2212 juvenile coho salmon (Oncorhynchus kisutch) 55 to 111 mm with Passive Integrated Transponder (PIT) tags to determine their growth, overwinter survival, and emigration timing from the East Twin River and its tributary, Sadie Creek, on Washingtons Olympic Peninsula. Detections of tagged fish by instream antennas revealed that a much higher proportion of juvenile coho salmon emigrated to the sea in the fall than during the spring. Fall emigrants predominantly originated from East Twin River (96.6%) whereas Sadie Creek coho salmon remained in-stream to overwinter where they grew faster and became larger when compared to smolts from East Twin River. Results suggest that fish size in the fall and location in the watershed may influence emigration timing.

Restoring Rivers in the Twenty-First Century: Science Challenges in a Management Context

Abstract Legal mandates force consideration of at least some level of river restoration in many developed nations (e.g., Clean Water and Endangered Species Act in the United States, or the Water Framework Directive in the European Union), but a lack of specifics in legislation compels decision-makers to ask three persistent management questions: (1) How much river restoration do we need? (2) How do we best achieve cost-effective river restoration? (3) How do we know we have restored enough? Moreover, the broader management context is permeated with tremendous inertia to continue development of rivers for societal and economic gain, continual application of small and fragmented restoration actions, and skepticism that river restoration can succeed in the face of climate change and steady population growth. It is in this context that we identify key science challenges for river restoration in the twenty-first century. We suggest that a fundamental shift toward restoring watershed and river processes (process-based restoration) is needed if scientists are to begin developing the tools needed to provide relevant policy answers. The basic conceptual framework of process-based restoration requires that we understand how habitat is formed and changes, how habitat changes alter biota, and how human actions alter both river habitats and the landscape processes that create river habitats. Restoration actions must then directly address human actions that caused habitat degradation, thereby addressing the root causes of biological impacts. Understanding this framework will allow scientists to better address key science challenges for advancing river restoration, including development of eco-system models to predict what kinds of and how much restoration is needed, an expanded suite of process-based restoration techniques for large river ecosystems, and comprehensive but cost-effective suites of metrics for monitoring river health.

Adult Coho Salmon and Steelhead Use of Boulder Weirs in Southwest Oregon Streams

Abstract The placement of log and boulder structures in streams is a common and often effective technique for improving juvenile salmonid rearing habitat and increasing fish densities. Less frequently examined has been the use of these structures by adult salmonids. In 2004, spawner densities and redd counts of coho salmon Oncorhynchus kisutch in seven Oregon streams were compared between 10 reach pairs: reaches with artificially placed boulder weir structures (treatment) and reaches without weirs (control). In addition, based on annual spawner survey data collected from 2001 to 2005, redd density of steelhead O. mykiss and spawner and redd densities of coho salmon were examined to assess differences among main-stem reaches with boulder weirs, main-stem reaches without weirs, and tributary reaches without weirs throughout one basin (West Fork of the Smith River (WFS)). Numbers of coho salmon spawners and peak redd counts were significantly higher (P ≤ 0.05) in treatment reaches than in control reaches in ...

Comparing Stream Restoration Project Effectiveness Using a Programmatic Evaluation of Salmonid Habitat and Fish Response

AbstractHundreds of millions of dollars have been spent on stream restoration projects to benefit salmonids and other aquatic species across the Pacific Northwest, though only a small percentage of these projects are monitored to evaluate effectiveness and far fewer are tracked for more than 1 or 2 years. The Washington State Salmon Recovery Board and the Oregon Watershed Enhancement Board have spent more than US

Rehabilitation of bedrock stream channels: the effects of boulder weir placement on aquatic habitat and biota†

500 million on salmonid habitat restoration projects since 1999. We used a multiple before-after–control-impact design to programmatically evaluate the reach-scale physical and biological effectiveness of a subset of restoration actions. A total of 65 projects in six project categories (fish passage, instream habitat, riparian planting, livestock exclusion, floodplain enhancement, and habitat protection) were monitored over an 8-year period. We conducted habitat, fish, and macroinvertebrate surveys to calculate the following indicators: longitudinal pool cross section and depth, riparian shade an...