The probability of different levels depensation within four taxonomic groups was calculated using a Bayesian technique called hierarchical modeling. With this method we combined spawner-recruit data from many stocks taxon to estimate the distribution describing variability that taxon. model use allows for both (lower than expected recruits at low population levels) and hypercompensation (where are higher levels). end product our analysis is can be used as prior when analyzing new set. We...

We review the evidence supporting depensation, describe models of two depensatory mechanisms and how they can be included in population dynamics discuss implications depensation. The for depensation grouped into four mechanisms: reduced probability fertilisation, impaired group dynamics, conditioning environment predator saturation. Examples these come from a broad range species including fishes, arthropods, birds, mammals plants. Despite large number studies mechanisms, there is very little...

ABSTRACT Since 1997, cases of Vibrio parahaemolyticus -related gastroenteritis from the consumption raw oysters harvested in Washington State have been higher than historical levels. These shown little or no correlation with concentrations potentially pathogenic V. (positive for thermostable direct hemolysin gene, tdh ) oysters, although significant + strains were isolated shellfish-growing areas Pacific Northwest (PNW). We compared clinical and environmental PNW to those other geographic...

Abstract We describe six habitat types for large rivers (>100 m bank‐full width), including pools, riffles, and glides in midchannel bank edges, bar backwaters along channel margins. Midchannel units were deeper faster than edge on average. Among types, backwater had the lowest velocities contained complex cover consisting mainly of wood accumulations aquatic plants. Banks bars similar velocity distributions, but banks more such as rootwads debris jams. Because sampling juvenile salmonids...

Populations of Vibrio parahaemolyticus in the environment can be influenced by numerous factors. We assessed correlation total (tl+) and potentially virulent (tdh+) V. water with three harmful algal bloom (HAB) genera (Pseudo-nitzschia, Alexandrium Dinophysis), abundance diatoms dinoflagellates, chlorophyll-a temperature, salinity macronutrients at five sites Washington State from 2008–2009. The variability density was explained predominantly strong seasonal trends where maximum densities...

Dam construction and longitudinal river habitat fragmentation disrupt important life histories movement of aquatic species. This is especially true for Oncorhynchus mykiss that exhibits both migratory (steelhead) non-migratory (resident rainbow) forms. While the negative effects dams on salmonids have been extensively documented, few studies had opportunity to compare population genetic diversity structure prior following dam removal. Here we examine impacts removal two Elwha River genetics...

Abstract Understanding the factors influencing success of juvenile Pacific salmon Oncorhynchus spp. in newly colonized habitats is essential to their recovery large areas across West Coast United States and Canada. We studied biotic abiotic associated with survival during early stages colonization population establishment coho O. kisutch Rock Creek, a tributary upper Cedar River Lake Washington basin Puget Sound, Washington. The stream was occupied by resident fishes (e.g., rainbow trout...

Abstract Juvenile salmon transitioning from freshwater to marine environments experience high variation in growth and survival, yet the specific causes of this are poorly understood. Size at timing ocean entry may contribute because they influence both availability prey vulnerability predators. To explore issue, we used stock assignments based on genetic identification internal tags document stock-specific size juvenile hatchery presumed wild Columbia River Chinook Salmon Oncorhynchus...

ABSTRACT Engineered log jams (ELJs) are increasingly being used in large rivers to create fish habitat and as an alternative riprap for bank stabilization. However, there have been few studies that systematically examined how juvenile salmonids utilized these structures relative other available habitat. We Chinook salmon ( Oncorhynchus tshawytscha ), coho O. kisutch ) trout mykiss clarki response the placement of engineered Elwha River, Washington State, USA. summer snorkel surveys a paired...

Abstract In 2012 the lower of two Elwha River dams was breached, restoring access anadromous salmonids to middle (between dams), including distinct tributaries, Indian Creek and Little River. While comparable in size, is considerably less steep than (mean slope 1.0% versus 3.5%, respectively) has a warmer stream temperature regime due its source, Lake Sutherland. During after breaching, Coho Salmon Oncorhynchus kisutch were relocated these tributaries from hatcheries (below dams) determine...

Abstract Riverine fishes face many challenges including habitat degradation and climate change, which alter the productivity of riverscapes in fish live, reproduce, feed. Understanding watershed portfolio foraging growth opportunities that sustain productive resilient populations is important for prioritizing conservation restoration. However, spatiotemporal distribution availability food are poorly understood relative to other factors such as abiotic quantity quality (e.g., water...

Abstract: We compared summer stream temperature patterns in 40 small forested watersheds the Hoh and Clearwater basins western Olympic Peninsula, Washington, to examine correlations between previous riparian basin‐wide timber harvest activity temperatures. Seven were unharvested, while remaining 33 had 25% 100% of total basin harvested, mostly within last years. Mean daily maximum temperatures significantly different harvested unharvested basins, averaging 14.5°C 12.1°C, respectively....

Migrating animals rely on a variety of cues to guide them, but the relative importance those signals may vary with size, life stage, or location. During their initial ocean migration, yearling Chinook salmon (Oncorhynchus tshawytcha) from Columbia River have stock-specific spatial distributions that shift through time. We used two-process mixture model examine how distribution migrants three stocks varies as function geospatial (e.g., latitude and distance shore) environmental chlorophyll...

Human stressors block, eliminate, and simplify habitat mosaics, eroding landscapes’ life history diversity thus biological resilience. One goal of restoration is to alleviate human that suppress diversity, but responses these efforts are still coming into focus. Here, we report emerging in threatened salmonids ( Oncorhynchus spp.) repopulating the recently undammed Elwha River (WA, United States) adjacent environmentally distinct tributaries. The ~20 km tributaries entered <1 apart,...

Statisticians are in general agreement that there flaws how science is currently practiced; less to make repairs. Our prescription for a Post-p < 0.05 Era develop and teach courses expand our view of what constitutes the domain statistics thereby bridge undergraduate coursework graduate student experience applying research. Such can speed up process gaining statistical wisdom by giving students insight into human propensity errors, meaning single test within research project, ways which...

Abstract Mobile species are particularly affected by artificial barriers requiring large investments to restore connectivity. However, few large‐scale, long‐term studies have investigated the ecological outcomes of restoring connectivity for these species. Our study, spanning 15–20 years, quantified response trajectories, which represent temporal trends following disturbance, three native salmonids colonizing 20 km protected habitat restoration fish passage at Landsburg Dam, Cedar River, WA,...

Large dam removal is being used to restore river systems, but questions remain regarding their outcomes. We examine how the of two large dams in Elwha River, coupled with hatchery production and fishing closures, affected population attributes Chinook salmon ( Oncorhynchus tshawytscha ) steelhead O. mykiss ). Initial responses by returning adult was an increase number spatial extent natural origin fish. Although few naturally produced juvenile outmigrants were observed prior during removal,...

Abstract We censused juvenile salmonids and stream habitat over two consecutive summers to test the ability of models explain distribution Coho Salmon Oncorhynchus kisutch , young‐of‐the‐year (age‐0) steelhead O. mykiss parr (age ≥1) within a network consisting several different‐sized streams. Our network‐scale explained 27, 11, 19% variation in density Salmon, age‐0 steelhead, parr, respectively, but strong levels spatial autocorrelation were typically present residuals. Explanatory power...

Abstract Escapement goals for Chinook salmon, Oncorhynchus tshawytscha (Walbaum), populations tend to be highly uncertain due variability in, and in some cases complete absence of, spawner‐recruit data. A previous study of 25 from Oregon Alaska demonstrated that watershed size is a good predictor unfished equilibrium population size. Here this relationship further developed by evaluating series Bayesian hierarchical models increasing complexity. The model performed best included temporal...

Abstract To understand the interplay between habitat use and contemporary anadromous Pacific salmon, Oncorhynchus spp., distributions we explored associations of three species, pink ( O. gorbuscha ), chum keta ) Chinook salmon tshawytscha in streams Wood River system Bristol Bay, Alaska, where sockeye nerka are numerically dominant. We developed models to investigate occurrence nondominant relation characteristics density, using four decades presence abundance data. The frequency species...