A Synthesis of Tagging Studies Examining the Behaviour and Survival of Anadromous Salmonids in Marine Environments

This paper synthesizes tagging studies to highlight the current state of knowledge concerning the behaviour and survival of anadromous salmonids in the marine environment. Scientific literature was reviewed to quantify the number and type of studies that have investigated behaviour and survival of anadromous forms of Pacific salmon (Oncorhynchus spp.), Atlantic salmon (Salmo salar), brown trout (Salmo trutta), steelhead (Oncorhynchus mykiss), and cutthroat trout (Oncorhynchus clarkii). We examined three categories of tags including electronic (e.g. acoustic, radio, archival), passive (e.g. external marks, Carlin, coded wire, passive integrated transponder [PIT]), and biological (e.g. otolith, genetic, scale, parasites). Based on 207 papers, survival rates and behaviour in marine environments were found to be extremely variable spatially and temporally, with some of the most influential factors being temperature, population, physiological state, and fish size. Salmonids at all life stages were consistently found to swim at an average speed of approximately one body length per second, which likely corresponds with the speed at which transport costs are minimal. We found that there is relatively little research conducted on open-ocean migrating salmonids, and some species (e.g. masu [O. masou] and amago [O. rhodurus]) are underrepresented in the literature. The most common forms of tagging used across life stages were various forms of external tags, coded wire tags, and acoustic tags, however, the majority of studies did not measure tagging/handling effects on the fish, tag loss/failure, or tag detection probabilities when estimating survival. Through the interdisciplinary application of existing and novel technologies, future research examining the behaviour and survival of anadromous salmonids could incorporate important drivers such as oceanography, tagging/handling effects, predation, and physiology

Behaviour of juvenile Atlantic salmon, Salmo Salar L., in rapid- and slow-flowing sections of a small Norwegian stream

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Some Environmental Requirements of Atlantic Salmon

Homing of presmolts and adults of Atlantic salmon Salmo salar was demonstrated within the Alta River by hydroacoustic tagging and analysis of growth differences. In spite of small nonsystematic differences between spawning habitats used by sympatric populations of Atlantic salmon and brown trout Salmo trutta , no interspecific superimposition of redds of the two species was observed. Atlantic salmon inhabiting streams that are cold in winter spawn early, whereas Atlantic salmon in warm winter streams spawn late. Enhancement programs involving fish transplantations should take into account the thermal regimes of the donor and target streams. As a consequence of interspecific competition, presmolt Atlantic salmon are found at higher water velocities, farther from the banks, and in deeper water than other sympatric salmonids. In a Norwegian river partially dammed by weirs, brown trout became the dominant species in the weir basins, where water velocity was reduced, but the proportion of Atlantic salmon remained unchanged in the areas of the river between the weirs, where water velocity was unchanged. Different competitiveness by salmonid species under varying physical conditions should be considered when the effects of human activities in salmon streams are analyzed

Migration of adult Atlantic salmon (Salmo salar) - the effects of artificial freshets

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Migratory behaviour of adult wild and escaped farmed Atlantic salmon, Salmo salar l., Before, during and after spawning in a Norwegian river

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Sea Water Temperatures at Atlantic Salmon Smolt Entrance

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