Autumnal Habitat Shift of Juvenile Atlantic Salmon (Salmo salar) in a Small River

1983 ◽  
Vol 40 (6) ◽  
pp. 671-680 ◽  
Author(s):  
D. M. Rimmer ◽  
U. Paim ◽  
R. L. Saunders
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Habitat Management ◽  
Habitat Type ◽  
Population Estimates ◽  
Age Classes ◽  
Winter Habitat ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Absolute Population

Autumnal changes in behavior and distribution of three age-classes of juvenile Atlantic salmon (Salmo salar) were determined during 3 yr in the Little Sevogle River of northeastern New Brunswick. In summer, salmon were always observed above the streambed, each holding a station over a single, unshaded stone. About 84% of the entire population occurred in the run habitat-type, 12% in riffles and 5% in pools. Underwater visual censuses showed the salmon to be continuously numerous in summer, but, as soon as water temperature fell to or below 10 °C in autumn, they disappeared from their stations and their visible population decreased by 92–98%. Thereafter, the salmon were found almost exclusively in sheltered substrate chambers beneath surface streambed stones. However, salmon distribution among runs, riffles, and pools (77, 18, and 5%, respectively) did not differ significantly from that in summer. Trapping, marking, and absolute population estimates indicated neither dwindling nor egress of the resident population. Thus, instead of suddenly leaving the river area or moving to another habitat-type at low temperatures, the salmon merely moved from their unsheltered summer stations to sheltered winter stations within the streambed. The results indicate the importance of winter habitat management in managing juvenile Atlantic salmon populations.

Changes in the Selection of Microhabitat by Juvenile Atlantic Salmon (Salmo salar) at the Summer–Autumn Transition in a Small River

1984 ◽  
Vol 41 (3) ◽  
pp. 469-475 ◽  
Author(s):  
D. M. Rimmer ◽  
U. Paim ◽  
R. L. Saunders
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Water Depth ◽  
Water Velocity ◽  
Bottom Surface ◽  
Age Classes ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Wide Range ◽  
Maximum Water

Over three summers we used direct underwater observation to examine the summer to autumn differences in seven microhabitat properties of three age-classes of juvenile Atlantic salmon (Salmo salar) in the Little Sevogle River of northeastern New Brunswick. Salmon of all three age-classes occupied a wide range of water depths during summer, but were concentrated mainly in depths of 24–36 cm. In autumn, they occurred in this range almost exclusively. The streambed stones most closely associated with the individual positions of all ages were always <20 cm in summer and mostly (84–92%) <10 cm in diameter. In autumn, all ages were associated with home stones up to 40 cm in diameter, with 65–83% of the stones exceeding 20 cm; the size of home stones selected increased with fish age in autumn. There was no apparent relationship between the water depth and home stone size distributions occupied by all age-classes and available in the stream during either summer or autumn. Summer focal water velocity (velocity at the fish's snout) was predominantly 10–30 cm∙s−1 for 0+, 10–40 cm∙s−1 for 1+, and 30–50 cm∙s−1 for 2+ salmon, but during autumn it was almost always <10 cm∙s−1 for all ages. The bottom and surface water velocities as well as the maximum water velocity within 1 m of fish stations increased with fish age during summer and autumn. At the summer–autumn transition, 0+ salmon selected higher bottom, surface, and maximum water velocities, 2+ salmon selected lower velocities, but selection by 1+ salmon remained unchanged. We view substrate size followed by water depth as the primary properties influencing stream suitability for juvenile Atlantic salmon in autumn.

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
Sign in / Sign up

Export Citation Format

Share Document