Density-dependent diet composition of juvenile Atlantic salmon (Salmo salar)

2010 ◽  
Vol 20 (3) ◽  
pp. 384-392 ◽  
Author(s):  
Pål A. Martinussen ◽  
Grethe Robertsen ◽  
Sigurd Einum
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Diet Composition ◽  
Density Dependent ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon

Density-dependent habitat selection by juvenile Atlantic salmon (Salmo salar) in experimental riverine habitats

1999 ◽  
Vol 56 (7) ◽  
pp. 1298-1306 ◽  
Author(s):  
Tammo P Bult ◽  
Stephen C Riley ◽  
Richard L Haedrich ◽  
R John Gibson ◽  
Jan Heggenes
Keyword(s):  
Habitat Selection ◽  
Population Density ◽  
Atlantic Salmon ◽  
Habitat Use ◽  
Salmo Salar ◽  
Implicit Assumption ◽  
Experimental Conditions ◽  
Density Dependent ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon

We investigated habitat use of Atlantic salmon (Salmo salar) parr in experimental riverine enclosures made up of pool, riffle, and run habitats over a range of densities (0.1-1.25 fish·m-2) to test the implicit assumption in habitat modelling that habitat selection does not change with population density. Results indicated that habitat use changed with population density, with relatively more parr in pools and fewer in runs at higher population densities. Temperature influenced parr distribution, with relatively more parr in runs and fewer in riffles and pools at higher temperatures. Parr distribution was primarily affected by hydromorphological differences among pool, riffle, and run habitats. Effects of population density and temperature on use of pool, riffle, and run habitats were often as large as effects of hydromorphological differences among pool, riffle, and run habitats on fish distributions over the range of temperatures and densities observed. Results varied considerably, despite controlled experimental conditions. We concluded that habitat selection by juvenile Atlantic salmon parr may be density dependent and potentially quite variable.

Are wild populations ideally distributed? Variations in density-dependent habitat use by age class in juvenile Atlantic salmon (Salmo salar)

2008 ◽  
Vol 65 (8) ◽  
pp. 1667-1680 ◽  
Author(s):  
A. Jamie F. Gibson ◽  
Heather D. Bowlby ◽  
Peter G. Amiro
Keyword(s):  
Atlantic Salmon ◽  
Habitat Use ◽  
Salmo Salar ◽  
Habitat Quality ◽  
Normal Function ◽  
Age Classes ◽  
Density Dependent ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Habitat Gradient

We examined relationships between abundance and habitat use in three age classes of juvenile Atlantic salmon ( Salmo salar ) in the Stewiacke River, Nova Scotia, Canada. Using stream gradient as a proxy for habitat quality, we used a double half normal function, modified to include density dependence, to model the relationship between habitat quality and fish density. We found that density was asymmetrically distributed around a similar optimum gradient for all three age classes regardless of abundance. Habitat use was highly density-dependent for age-0 and age-1 juveniles, but not for age-2+ salmon. As abundance of age-0 and age-1 salmon increased, their relative density decreased in low-gradient habitat and increased in higher-gradient habitat, although their absolute density increased in all stream gradient categories. Variation in habitat use was consistent with ideal free theory for age-1 juveniles in high-gradient habitat, but not in low-gradient habitat. Age-2+ individuals appeared not to modify their distribution among habitats, even though increasing competition changes the relative benefit of low-gradient habitat in terms of resource acquisition. In contrast, age-1 individuals responded to increased competition by modifying their distribution along the habitat gradient, even though this may have slightly reduced an individual’s potential for growth.

scholarly journals Sulphated glycosaminoglycans and proteoglycans in the developing vertebral column of juvenile Atlantic salmon (Salmo salar)

2015 ◽  
Vol 41 (4) ◽  
pp. 1029-1051 ◽  
Author(s):  
Kirsten O. Hannesson ◽  
Elisabeth Ytteborg ◽  
Harald Takle ◽  
Grethe Enersen ◽  
Grete Bæverfjord ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Vertebral Column ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Sulphated Glycosaminoglycans

Effect of time of day, time of year, and life history strategy on time budgeting in juvenile Atlantic salmon, Salmo salar

1999 ◽  
Vol 56 (12) ◽  
pp. 2397-2403 ◽  
Author(s):  
Sveinn K Valdimarsson ◽  
Neil B Metcalfe
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Life History Strategy ◽  
Time Of Day ◽  
Life History Strategies ◽  
Foraging Efficiency ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Time Of Year

Traditionally, behavioural studies on juvenile Atlantic salmon, Salmo salar, have been conducted during the day in summer. It is known that Atlantic salmon become nocturnal in winter, but very little is known about their behaviour at that time. Therefore, observations in a seminatural stream were carried out during the day and night, from February to June, comparing diel and seasonal differences in behaviour between fish adopting alternative life history strategies. The results showed a general trend for more activity in spring than in winter, and the fish were found to be foraging at surprisingly low light levels. There were differences in relative feeding rate between the life history strategies; the early migrant fish foraged mostly during the day whereas the delayed migrant fish did more foraging at night. There is some evidence that the early migrant fish made fewer feeding attempts over the winter, which is surprising, since they grow faster over that period. This suggests differences in foraging efficiency, which could contribute to the separation into these two life history strategies.

Thermal performance of juvenile Atlantic Salmon, Salmo salar L.

2001 ◽  
Vol 15 (6) ◽  
pp. 701-711 ◽  
Author(s):  
B. JONSSON ◽  
T. FORSETH ◽  
A. J. JENSEN ◽  
T. F. NAESJE
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Thermal Performance ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon
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