The effect of turbulence on the cost of swimming for juvenile Atlantic salmon (Salmo salar)

2003 ◽  
Vol 60 (9) ◽  
pp. 1149-1160 ◽  
Author(s):  
Eva C Enders ◽  
Daniel Boisclair ◽  
André G Roy
Keyword(s):  
Atlantic Salmon ◽  
Turbulent Flow ◽  
Flow Velocity ◽  
Turbulent Flows ◽  
Salmo Salar ◽  
Forced Swimming ◽  
Mean Flow ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Wide Range

Fish activity costs are often estimated by transforming their swimming speed in energy expenditures with respirometry models developed while forcing fish to swim against a flow of constant velocity. Forced swimming models obtained using a procedure that minimizes flow heterogeneity may not represent the costs of swimming in rivers characterized by turbulence and by a wide range of instantaneous flow velocities. We assessed the swimming cost of juvenile Atlantic salmon (Salmo salar) in turbulent flows using two means (18 and 23 cm·s–1) and two standard deviations of flow velocity (5 and 8 cm·s–1). Twenty respirometry experiments were conducted at 15 °C with fish averaging 10 g. Our results confirmed that swimming costs are affected by the level of turbulence. For a given mean flow velocity, swimming costs increased 1.3- to 1.6-fold as turbulence increased. Forced swimming models under estimated actual swimming costs in turbulent flow by 1.9- to 4.2-fold. Spontaneous swimming models overestimated the real cost of swimming in turbulent flow by 2.8- to 6.6-fold. Our analyses suggest that models in which both the mean and the standard deviation of flow velocity are explicitly represented are needed to adequately estimate the costs of swimming against turbulent flows.

A model of total swimming costs in turbulent flow for juvenile Atlantic salmon (Salmo salar)

2005 ◽  
Vol 62 (5) ◽  
pp. 1079-1089 ◽  
Author(s):  
Eva C Enders ◽  
Daniel Boisclair ◽  
André G Roy
Keyword(s):  
Standard Deviation ◽  
Atlantic Salmon ◽  
Turbulent Flow ◽  
Water Temperature ◽  
Flow Velocity ◽  
Body Mass ◽  
Salmo Salar ◽  
Mean Flow ◽  
Juvenile Atlantic Salmon ◽  
Mean Flow Velocity

Juvenile Atlantic salmon (Salmo salar) live in rivers characterized by highly turbulent flows. In these environments, flow turbulence is associated with a wide range of instantaneous flow velocities, which may affect the energetic costs of habitat utilization of juvenile Atlantic salmon. The purpose of our work was to develop a swimming costs model for juvenile Atlantic salmon that especially accounts for the effects of velocity fluctuations in turbulent environments. We estimated the total swimming costs of fish in a respirometer in which we produced five turbulent flow conditions, each characterized by a mean and a standard deviation of flow. Respirometry experiments were conducted at water temperatures of 10, 15, and 20 °C with fish ranging in size between 4.3 and 17.6 g at three mean flow velocities (18, 23, and 40 cm·s–1) and three standard deviations of flow velocity (5, 8, and 10 cm·s–1). Our results confirmed that total swimming costs increased with an increase of water temperature, body mass, mean flow velocity, and standard deviation of flow velocity (R2 = 0.93). Water temperature, body mass, mean flow velocity, and standard deviation of flow velocity contributed respectively 2%, 31%, 46%, and 14% to the explained variation in total swimming costs.

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.

scholarly journals Position choice and swimming costs of juvenile Atlantic salmon salmo salar in turbulent flow

2017 ◽  
Vol 2 (1) ◽  
pp. 16-27 ◽  
Author(s):  
M.A. Wilkes ◽  
E.C. Enders ◽  
A.T. Silva ◽  
M. Acreman ◽  
I. Maddock
Keyword(s):  
Atlantic Salmon ◽  
Turbulent Flow ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon

Allometric and environmental correlates of territory size in juvenile Atlantic salmon (Salmo salar)

1995 ◽  
Vol 52 (1) ◽  
pp. 186-196 ◽  
Author(s):  
Ernest R. Keeley ◽  
James W. A. Grant
Keyword(s):  
Body Size ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Territory Size ◽  
Environmental Correlates ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Wide Range ◽  
Body Sizes ◽  
Young Of The Year

We observed juvenile Atlantic salmon (Salmo salar) over a wide range of stream conditions and body sizes to determine the relative importance of environmental factors and body size as predictors of territory size. Defended and foraging areas were virtually identical in size. Eighty-eight percent of the variation in territory size was explained by differences in body size and age; territory size increased with body size, but young-of-the-year salmon had relatively larger territories for their body size than older fish. Territory size was inversely related to food abundance, the only significant environmental correlate of territory size, but food only explained an additional 2% of the variation in territory size. Intruder pressure, visual isolation, and current velocity were not significantly related to territory size. The allometric scaling of territory size was consistent with the hypothesis that Atlantic salmon maintain a maximum daily ration of drift flowing over their territory. Atlantic salmon in Catamaran Brook have larger territories than is reported in the literature for other stream-dwelling salmonids of a similar size.

scholarly journals Seasonal shift in the effects of predators on juvenile Atlantic salmon (Salmo salar) energetics

2011 ◽  
Vol 68 (12) ◽  
pp. 2080-2089 ◽  
Author(s):  
Darren M. Ward ◽  
Keith H. Nislow ◽  
Carol L. Folt
Keyword(s):  
Population Density ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Large Scale ◽  
Balance Model ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Wide Range ◽  
Salmon Population ◽  
Predator Effects

Predator effects on prey populations are determined by the number of prey consumed and effects on the traits of surviving prey. Yet the effects of predators on prey traits are rarely evaluated in field studies. We measured the effects of predators on energetic traits (consumption and growth rates) of juvenile Atlantic salmon ( Salmo salar ) in a large-scale field study. Salmon fry were released at 18 sites that encompassed a wide range of predatory slimy sculpin ( Cottus cognatus ) abundance. We sampled salmon after 21 and 140 days to measure salmon growth and estimate consumption using a mass-balance model of methylmercury accumulation. Salmon population density was reduced fivefold at sites with abundant sculpin. Over the early season, salmon consumed less where sculpin were abundant, suggesting that reduced foraging under predation risk contributed to predator-caused mortality. In contrast, over the late season, salmon grew more where sculpin were abundant, suggesting that compensatory growth at reduced salmon population density moderated predator-caused mortality. Predator effects on prey energetics can drive variation in survival and growth, with important consequences for population dynamics.

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