Fish and Aquatic Species Publications

Viral hemorrhagic septicemia virus (VHSV), a fish rhabdovirus belonging to the Novirhabdovirus genus, causes severe disease and mortality in many marine and freshwater fish species worldwide. VHSV isolates are classified into four genotypes and each group is endemic to specific geographic regions in the north Atlantic and Pacific Oceans. Most viruses in the European VHSV genotype Ia are highly vir

Atlantic salmon farming is one of the largest aquaculture sectors in the world. A major impact on farm economics, fish welfare, and potentially nearby wild salmonid populations, is the sea louse ectoparasite Lepeophtheirus salmonis. Sea louse infestations are most often controlled through application of chemicals, but in most farming regions sea lice have evolved resistance to the small set of ava

A field study was conducted to estimate survival of fry-sized juvenile Chinook salmon (Oncorhynchus tshawytscha) in Lookout Point Reservoir, western Oregon, during 2017. The field study consisted of releasing three groups of genetically marked fish in the reservoir and monthly fish sampling. Fish were released during April 18–19 (43,950 fish), May 30–June 2 (44,145 fish), and on June 28, 2017 (3,9

Executive SummaryThe recovery of endangered Lost River suckers (Deltistes luxatus) in Upper Klamath Lake, south-central Oregon, has been impeded because juveniles are not recruiting into adult spawning populations. Adult sucker populations spawn each spring but mortality of age-0 suckers during their first summer is excessively high, and recruitment of juveniles into adult populations does not occ

Infectious hematopoietic necrosis virus (IHNV) is a well-known rhabdoviral pathogen of salmonid fish. In this study, a comprehensive analysis of 40 IHNV viruses isolated from thirteen fish farms in nine geographically dispersed Chinese provinces during 2012 to 2017 is presented. Identity of nucleotide and amino acid sequences among all the complete glycoprotein (G) genes from Chinese isolates was

Large river deltas are complex ecosystems that are believed to play a pivotal role in promoting the early marine growth and survival of threatened Chinook Salmon Oncorhynchus tshawytscha. We used a fish bioenergetics model to assess the functional role of multiple delta habitats across a gradient of salinities and vegetation types, where consumption and growth rate potential (GRP) were considered

Providing efficient downstream passage is critical for improving populations of migratory fishes in impounded river systems. High‐head dams, such as those used for water storage or flood‐risk management, pose unique passage challenges requiring unique solutions. Systems to collect fish in dam forebays (“forebay collectors”) for transport to downstream release locations have been used at some high‐

One of the desired outcomes of dam decommissioning and removal is the recovery of aquatic and riparian ecosystems. To investigate this common objective, we synthesized information from empirical studies and ecological theory into conceptual models that depict key physical and biological links driving ecological responses to removing dams. We define models for three distinct spatial domains: upstre

Bacterial kidney disease (BKD) caused by Renibacterium salmoninarum (Rs) occurs nearly worldwide where wild or cultured salmonid fishes are present. Control of BKD is confounded by its two modes of transmission, horizontal (fish-to-fish) and vertical (from female parent to progeny via the eggs). A highly successful BKD control strategy employed in Pacific Northwest hatcheries culturing spring Chin

It is asserted that reduction or elimination of hatchery stocking will increase natural‐origin salmon Oncorhynchus spp. and steelhead O. mykiss production. We conducted an analysis of steelhead population census data (1958–2017) to determine whether elimination of summer steelhead stocking in the upper Clackamas River in 1998 increased the productivity of natural‐origin winter steelhead. A Bayesia

The reintroduction of extirpated salmonids to historically occupied areas is becoming increasingly common as a conservation and recovery strategy. Often, reintroductions are implemented after the factors that originally led to species extirpation have been reduced, eliminated, or mitigated. For anadromous Oncorhynchus spp. (Pacific salmon) and O. mykiss (steelhead), addressing barriers to migratio

Risks associated with disease spread from fish and shellfish farming have plagued the growth and public perception of aquaculture worldwide. However, by processing nutrients and organic material from the water column, the culture of many suspension-feeding bivalves has been proposed as a novel solution toward mitigating problems facing coastal water quality, including the removal of disease-causin

Release of age‐0 hatchery‐reared fall Chinook salmon, Oncorhynchus tshawytscha(Walbaum), in the Snake River resulted in up to 30‐fold increases in salmon consumption by non‐native smallmouth bass, Micropterus dolomieu Lacepѐde. In an upper river reach, smallmouth bass fed intensively during a release in May, but Chinook salmon consumption returned to pre‐release levels within 1–2 days as hatchery‐

An imaging sonar was used to assess the behavior and abundance of fish sized the same as salmonid smolt and bull trout (Salvelinus confluentus) at the entrance to the juvenile fish floating surface collector (FSC) at North Fork Reservoir, Oregon. The purpose of the FSC is to collect downriver migrating juvenile salmonids (Chinook salmon [Oncorhynchus tshawytscha], Coho salmon [Oncorhynchus kisutch

Executive SummaryIn this report, we constructed and parameterized the Stream Salmonid Simulator (S3) for the 64-kilometer “Restoration Reach” of the Trinity River, just downstream of Lewiston Dam in northern California. S3 is a deterministic life-stage-structured population model that tracks daily growth, movement, and survival of juvenile salmon. A key theme of the model is that river flow affect

Recent field surveillances indicated that outmigrating steelhead smolts in several south Puget Sound watersheds are infected with the digenean trematode Nanophyetus salmonicola at high prevalence and intensity (Chen et al Accepted). The apparent severity of these infections, especially in the Nisqually and Green / Duwamish Rivers, lead to the hypothesis that Nanophyetus may play a role as a proxim

This review summarizes what is known about the influence of water temperature and velocity on the migration and spawning success of an inland population of Chinook salmon Oncorhynchus tshawytscha. Models are then developed and used to illustrate how migration and spawning success might change if temperatures and velocities increase under a future climate. The illustration shows the potential for m

Life-cycle models combine several strengths for estimating population parameters and biological reference points of harvested species and are particularly useful for those exhibiting distinct habitat shifts and experiencing contrasting environments. Unfortunately, time series data are often limited to counts of adult abundance and harvest. By incorporating data from other populations and by dynami

The Bureau of Reclamation supports the Shasta Dam Fish Passage Evaluation (SDFPE; Yip, 2015) program, and in 2016 set out to determine the feasibility of reintroducing winter-run and spring-run Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) to tributaries upstream of Shasta Dam. Ideally, reintroduction strategy includes trapping naturally produced downstream-migrating juvenile

High water temperatures can increase the energetic cost for salmon to migrate and spawn, which can be important for Snake River fall‐run Chinook salmon because they migrate great distances (>500 km) at a time when river temperatures (18–24°C) can be above their optimum temperatures (16.5°C). Average river temperatures and random combinations of migration and spawning dates were used to simulate fi

Hatchery programs have been used as a conservation tool to bolster declining populations of Chinook Salmon Oncorhynchus tshawytscha along much of the North American Pacific coast. In many watersheds, hatchery stocks are released concurrently with the wild population, thus raising the potential for density‐dependent effects. Competition for prey resources during the critical period for early marine