Positioning of sea cages at sites with high water current velocities expose the fish to a largely unknown environmental challenge. In this study we observed the swimming behaviour of Atlantic salmon (Salmo salar L.) at a commercial farm with tidal currents altering between low, moderate and high velocities. At high current velocities the salmon switched from the traditional circular polarized g...

Thalweg profiles are longitudinal profiles of the streambed elevation measured along the deepest portion of the stream. This technique has recently been advocated as a tool to monitor fish habitat in streams because profiles can provide useful information on such habitat, and measurements are both repeatable and independent of stream flow. However, a relation between fish abundance and metrics ...

Fishery management programs designed to control Pacific salmon (Oncorhynchus spp.) for optimum production have failed to prevent widespread fish population decline and have caused greater uncertainty for salmon, their ecosystems, and the people who depend upon them. In this special feature introduction, we explore several key attributes of ecosystem resilience that have been overlooked by tradi...

A plasmacytoid leukemia (PL) has caused mortalities in chinook salmon (Oncorhynchus tshawytscha) reared in seawater netpens in western British Columbia, Canada, since 1988. Kidney or eye tissues from 11 of 13 fish from netpens with clinical PL had reverse transcriptase (RT) activity. This RT activity was associated with virus particles of retrovirus morphology and buoyant density. In a transmis...

approved: Signature redacted for privacy. Dr5. L. }yer The purpose of this study was to characterize Cytophaga psychrophila isolates obtained from coho fingerlings with low temperature disease collected at selected hatcheries in Oregon. In addition, cultures thought to be related to this bacterium were isolated from Siletz Hatchery water, deformed juvenile and spawning adult coho salmon, rainbo...

The newly described piscine reovirus (PRV) appears to be associated with the development of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon Salmo salar L. PRV seems to be ubiquitous among fish in Norwegian salmon farms, but high viral loads and tissue distribution support a causal relationship between virus and disease. In order to improve understanding of the distributi...

Leptin plays an important role in energy homeostasis and reproductive function in fish, especially in reproduction. Migrating fish, such as salmonoids, are affected by external environmental factors, and salinity changes are a particularly important influence on spawning migrations. The aim of this study was to test whether changes in salinity affect the expression of leptin, estrogen receptors...

The manuscript summarizes the results of a travel cost model developed for recreational angling in Michigan. The model and method are briefly described. The discussion focusses on how Great Lakes trout and salmon catch rates were related to angler behavior. The model is used to value changes in trout and salmon catch rates at Great Lakes fishing sites in Michigan. Fish population levels can be ...

The presence of Aeromonas salrnonicida, the etiological agent of furunculosis, was examined using polymerase chain reaction (PCR) and DNA probe methodology in wild Atlantic salmon Salmo salar taken from 3 Irish river systems Blood samples from 61 individual fish were examined and the presence of pathogen was determined in 87% of the fish examined. However, the level of pathogen was extremely lo...

The live release of wild adult Pacific salmon (Oncorhynchus spp.) following capture is a management tactic often used in commercial, aboriginal, and recreational fisheries. Fisheries capture and handling can be both exhausting and stressful to fish, which can limit their ability to swim and survive after release. As a result, researchers have assessed methods intended to improve post-release su...