Philip Roni

A Review of Stream Restoration Techniques and a Hierarchical Strategy for Prioritizing Restoration in Pacific Northwest Watersheds

Abstract Millions of dollars are spent annually on watershed restoration and stream habitat improvement in the U.S. Pacific Northwest in an effort to increase fish populations. It is generally accepted that watershed restoration should focus on restoring natural processes that create and maintain habitat rather than manipulating instream habitats. However, most process-based restoration is site-specific, that is, conducted on a short stream reach. To synthesize site-specific techniques into a process-based watershed restoration strategy, we reviewed the effectiveness of various restoration techniques at improving fish habitat and developed a hierarchical strategy for prioritizing them. The hierarchical strategy we present is based on three elements: (1) principles of watershed processes, (2) protecting existing high-quality habitats, and (3) current knowledge of the effectiveness of specific techniques. Initially, efforts should focus on protecting areas with intact processes and high-quality habitat. Fol...

Process-based Principles for Restoring River Ecosystems

Process-based restoration aims to reestablish normative rates and magnitudes of physical, chemical, and biological processes that sustain river and floodplain ecosystems. Ecosystem conditions at any site are governed by hierarchical regional, watershed, and reach-scale processes controlling hydrologic and sediment regimes; floodplain and aquatic habitat dynamics; and riparian and aquatic biota. We outline and illustrate four process-based principles that ensure river restoration will be guided toward sustainable actions: (1) restoration actions should address the root causes of degradation, (2) actions must be consistent with the physical and biological potential of the site, (3) actions should be at a scale commensurate with environmental problems, and (4) actions should have clearly articulated expected outcomes for ecosystem dynamics. Applying these principles will help avoid common pitfalls in river restoration, such as creating habitat types that are outside of a sites natural potential, attempting to build static habitats in dynamic environments, or constructing habitat features that are ultimately overwhelmed by unconsidered system drivers.

Geographic Variation in Size and Age of North American Chinook Salmon

Abstract Patterns of mean length and length at age were characterized and compared for 108 populations of chinook salmon Oncorhynchus tshawytscha located between 42 and 65° north latitude in western North America. Mean overall fish length in populations ranged over 45.5 cm for adult males and 28.8 cm for females. Mean length at a given marine age and freshwater life history type varied by up to 26 cm. Mean length at marine age did not differ between stream-type and ocean-type life histories, which indicates that differences in size and date of ocean entry had little effect on final size. Hatchery-reared fish were significantly smaller at a given age than naturally produced fish. Chinook salmon from the Kenai, Kitsumkalum, and Wannock rivers had the largest total mean lengths of the 108 populations, and were also the largest at marine ages 4 and 5. These populations appear to represent extremes in both body size and reproductive life history. There are many selective advantages of large body size, but no c...

Estimating Winter Salmonid Abundance in Small Western Washington Streams: A Comparison of Three Techniques

Abstract We compared the relative efficiency of day snorkeling, night snorkeling, and multiple-removal electrofishing at estimating abundance of juvenile coho salmon Oncorhynchus kisutch and trout Oncorhynchus spp. during winter in four small western Washington streams. Salmonid abundance was estimated within 32 individual habitats at low to moderate winter flows and low water temperatures (<7.0°C). Day snorkel counts were significantly less than both night snorkel counts and multiple-removal electrofishing estimates. Night snorkel counts were not significantly different from electrofishing estimates, although the percentage of electrofishing estimates accounted for by night snorkeling varied by stream from 50% to 175% for coho salmon and from 75% to 82% for trout. The difference between electrofishing estimates and night snorkel counts was positively correlated with fish density for coho salmon, indicating that night snorkel counts were most similar to electrofishing estimates at densities less than 0.5 ...

Habitat Use by Fishes and Pacific Giant Salamanders in Small Western Oregon and Washington Streams

Abstract The habitat use patterns of juvenile salmonid fishes Oncorhynchus spp., Pacific giant salamanders Dicamptodon spp., torrent sculpins Cottus rhotheus, reticulate sculpins C. perplexus, and larval lampreys Entosphenus tridentatus and Lampetra spp. were examined in 30 small streams in western Oregon and Washington. Fish and salamander densities and sizes were compared between different habitat types (pools and riffles) in summer and winter. Species density, length, and diversity (richness and dominance) were also correlated with physical variables measured at the reach and watershed scales. In the summer, densities of coho salmon O. kisutch, cutthroat trout O. clarki, and larval lampreys were significantly higher in pools than in riffles (P < 0.01), whereas densities of age-0 torrent sculpins were higher in riffles than in pools (P < 0.01). In winter, densities of coho salmon, cutthroat trout, steelhead O. mykiss, and young-of-the-year trout fry were higher in pools than in riffles (P < 0.01). Cutth...

Effects of Wood Placement on Movements of Trout and Juvenile Coho Salmon in Natural and Artificial Stream Channels

Abstract We monitored the movements of marked juvenile coho salmon Oncorhynchus kisutch, steelhead O. mykiss, and cutthroat trout O. clarki in a stream reach that had been “restored” with placed wood and a reference reach with no wood placement and tracked the growth and movements of individually marked coho salmon among habitats in artificial channels with and without woody debris. Monthly surveys in Shuwah Creek, Washington, indicated that few (0–33%) of the marked trout or coho salmon moved between the restored and reference reaches. However, a rapid decline in both marked and unmarked fish in late fall and the increasing proportion of unmarked fish indicated considerable migration to and from the study reaches. In the artificial channels, fewer fish moved in the simple (with no wood) channel than in the complex (with wood) channel (22% versus 37%), and the mean distance moved was shorter in the complex channel (4.4 versus 6.7 habitat units). In the simple channel, the fish that moved grew faster than ...

Factors Affecting Migration Timing, Growth, and Survival of Juvenile Coho Salmon in Two Coastal Washington Watersheds

Abstract Recent improvements in tagging technology allow for the examination of the migration of individual fish, the detection of previously unidentified life histories, and the detailed examination of factors affecting growth, migration, and survival. Using passive integrated transponder tags and instream readers installed near tidewater, we examined the migration, growth, and survival of 18,642 juvenile coho salmon Oncorhynchus kisutch in two small western Washington rivers from 2005 to 2009. In most years, more than 50% of the juvenile coho salmon from a given brood year migrated to sea between 1 October and 31 December (fall migrants). These fall migrants were significantly smaller at tagging than fish that migrated between 1 January and 30 June (spring migrants) but were similar in size to fish that were never detected after tagging and assumed to have died. Annual coho salmon survival estimates from tagging to out-migration ranged from 31% to 40% for fall and spring migrants combined but from 5% to...

Responses of Benthic Fishes and Giant Salamanders to Placement of Large Woody Debris in Small Pacific Northwest Streams

Abstract The placement of large woody debris (LWD) to improve or restore habitat for fishes is a common practice in North American streams, and the responses of salmonids to this practice have frequently been examined. In contrast, little information exists on the effects of LWD placement on nonsalmonid fishes and amphibians. In this study, I examined the responses of giant salamanders Dicamptodon spp., juvenile lampreyss Entosphenus tridentatus and Lampetra spp., reticulate sculpins Cottus perplexus, and torrent sculpins C. rhotheus to artificially placed LWD by sampling 29 small streams with paired treatment and reference reaches. Densities and mean lengths of giant salamanders, reticulate sculpins, torrent sculpins, and lampreyss did not differ significantly between treatment and references reaches. I also examined whether the observed responses were correlated with differences in physical habitat between reference and treatment reaches. Lampreys densities (log10(treatment) − log10(reference)) and leng...

Parental Effect as a Primary Factor Limiting Egg-to-Fry Survival of Spring Chinook Salmon in the Upper Yakima River Basin

Abstract Few field estimates of egg-to-fry survival of Chinook salmon Oncorhynchus tshawytscha exist, although it is one of the major factors thought to limit freshwater production and recovery of Chinook salmon populations. This is likely due to the challenges of estimating survival at this life stage, which is further complicated by the variety of methods that have been employed. Our study objectives were to (1) develop a method by which spring Chinook salmon egg-to-fry survival could be estimated at a large spatial scale, and (2) investigate the primary factors affecting survival in the natural environment. We conducted a field experiment using 81 artificial redds to test our proposed method for evaluating egg-to-fry survival at a basin scale and to evaluate the effects of parentage (adult mating), river reach, and fine sediment infiltration on survival in the upper Yakima River basin, Washington. Egg-to-fry survival and preemergent Chinook salmon fry developmental stage were significantly different am...

Life History Diversity of Steelhead in Two Coastal Washington Watersheds

AbstractWe used PIT tags implanted in juvenile Oncorhynchus mykiss to monitor movement into and out of two coastal Washington State rivers, East Twin River and West Twin River. Movement patterns revealed at least 18 life histories of steelhead O. mykiss with variations in age and seasonal migration of juveniles, juvenile use of the ocean prior to migration, years spent in the ocean, season of adult return, and iteroparity. While most migrants left the river in their first fall or winter, we did not detect any returning adults from these age-0 migrants. Adults were only produced from age-1 and older migrants, of which most were age-2 spring migrants that returned after two summers in the ocean. Our results indicated a positive relationship between fish length at tagging and the probability of being detected as a migrant, while the probability of a migrant leaving at age 1 and older decreased with increasing length at tagging among fish that were detected as migrants. We hypothesize that fish attaining a la...