Consequences of circadian fluctuations in water temperature on the standard metabolic rate of Atlantic salmon parr (Salmo salar)

2013 ◽  
Vol 70 (7) ◽  
pp. 1072-1081 ◽  
Author(s):  
David Beauregard ◽  
Eva Enders ◽  
Daniel Boisclair
Keyword(s):  
Atlantic Salmon ◽  
Metabolic Rate ◽  
Water Temperature ◽  
Salmo Salar ◽  
Traditional Approach ◽  
Standard Metabolic Rate ◽  
Fish Growth ◽  
Salmon Parr ◽  
Model Components ◽  
Atlantic Salmon Parr

Fish that inhabit rivers may experience important daily fluctuations in water temperature. Bioenergetic models have the potential to simulate the effects of such fluctuations on fish growth; however, bioenergetic components are traditionally modeled using fish kept at constant water temperatures. This study tested the hypothesis that circadian fluctuations in water temperature increase the standard metabolic rate of fish. The standard metabolic rate of Atlantic salmon parr (Salmo salar; 5.96–36.20 g wet blotted mass) estimated at 20 ± 0.5 °C was 25% to 32% lower for fish held at a relatively constant water temperature (20.2 ± 0.5 °C) than for fish maintained under fluctuating thermal regimes (19.8 ± 2.0 °C; 19.5 ± 3.0 °C). This study suggests that a rise in standard metabolic rate may explain how temperature fluctuations affect fish growth. It also indicates that the traditional approach used to estimate and model components of the bioenergetic equation may substantially underestimate the standard metabolic rate of fish that are subjected to such fluctuations.

Effects of Elevated Winter Temperature on Seawater Adaptability, Sexual Rematuration, and Downstream Migratory Behaviour in Mature Male Atlantic Salmon Parr (Salmo salar)

1991 ◽  
Vol 48 (6) ◽  
pp. 1041-1047 ◽  
Author(s):  
I. Berglund ◽  
L. P. Hansen ◽  
H. Lundqvist ◽  
B. Jonsson ◽  
T. Eriksson ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Water Temperature ◽  
Salmo Salar ◽  
Mature Male ◽  
Potential Yield ◽  
Simple Method ◽  
Winter Temperatures ◽  
Salmon Parr ◽  
Winter Water Temperature ◽  
Atlantic Salmon Parr

In experiments with two different salmon (Salmo salar) stocks, elevated winter temperatures (Celsius) 4–9° above the ambient increased the degree of testicular resorption in previously mature male Atlantic salmon parr. Two-summer-old mature male parr maintained at a temperature 9° over the ambient for 5 mo (January–May) showed an increase in hypoosmoregulatory ability when challenged in seawater at the time of smoltification whereas parr kept at elevated temperature for various 2-mo periods (January–February, February–March, or March–April) failed to show this improvement. Furthermore, previously mature males kept at an elevated winter water temperature for either 2 or 5 mo showed a lower incidence of sexual rematuration, and consequently a higher mean growth rate, after one summer in sea pens. A river release experiment showed that rearing previously mature males at 4–7° above the ambient water temperature from December to April increased the number of downstream migrating fish to a level similar to that of immature smolts. We suggest the use of a simple method for enhancing the potential yield of ranched and cultured salmon from early maturing males by removing them from the stock population and rearing them over winter in heated water.

Influence of Body Size on Silvering of Atlantic Salmon (Salmo salar) at Parr–Smolt Transformation

1970 ◽  
Vol 27 (5) ◽  
pp. 983-987 ◽  
Author(s):  
C. E. Johnston ◽  
J. G. Eales
Keyword(s):  
Body Size ◽  
Atlantic Salmon ◽  
Water Temperature ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar ◽  
Salmon Parr ◽  
Negligible Influence ◽  
Atlantic Salmon Parr

Large yearling Atlantic salmon parr turn silvery more quickly than small parr when held under a series of controlled temperature and photoperiod regimes. Photoperiod appeared to exert a negligible influence on silvering, and water temperature was the main controlling variable.

Degradation of DDT in Atlantic Salmon (Salmo salar)

1968 ◽  
Vol 25 (11) ◽  
pp. 2321-2326 ◽  
Author(s):  
G. L. Greer ◽  
U. Paim
Keyword(s):  
Atlantic Salmon ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Salmo Salar ◽  
Aqueous Suspensions ◽  
Atlantic Salmon Salmo Salar ◽  
Salmon Parr ◽  
Layer Chromatography ◽  
Atlantic Salmon Parr

As indicated by thin-layer chromatography, hatchery-reared Atlantic salmon parr degraded DDT, absorbed from aqueous suspensions, to DDE and TDE within 9 hr. DDT adsorbed on external surfaces of the salmon was not degraded.

Assessment of the transferability of biological habitat models for Atlantic salmon parr (Salmo salar)

2003 ◽  
Vol 60 (11) ◽  
pp. 1398-1408 ◽  
Author(s):  
J C Guay ◽  
D Boisclair ◽  
M Leclerc ◽  
M Lapointe
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Mathematical Structure ◽  
Habitat Patches ◽  
Suitability Index ◽  
Preference Curve ◽  
Substrate Size ◽  
Salmon Parr ◽  
Predicted Values ◽  
Atlantic Salmon Parr

We assessed the transferability of the habitat suitability index (HSI) and the habitat probabilistic index (HPI) between two rivers. Transferability was measured by the ability of HSI and HPI models developed in the Sainte-Marguerite River to predict the distribution of Atlantic salmon parr (Salmo salar) in the Escoumins River. HSI and HPI were based on the pattern of utilization by fish of water depth, current velocity, and substrate size. HSI was developed using the preference curve approach, and HPI was developed using a multiple logistic regression. Predicted values of HSI and HPI in Escoumins River ranged from 0 (poor habitat) to 1 (excellent habitat). Fish density in habitat patches assigned different HSI or HPI values ranged from 0 to 1 fish·100 m–2. Only HPI adequately predicted local variations in parr density (r2 = 0.84) in habitat patches of Escoumins River. Our results suggest that HSI is less transferable between rivers than HPI. Differences in substrate size between the two rivers is suspected to impede the transferability of the HSI model. We also argue that the mathematical structure of HPI provides a larger degree of flexibility that facilitates its transferability and its potential generalization.

Downstream Movements and Estuarine Residence by Atlantic Salmon Parr (Salmo salar)

1989 ◽  
Vol 46 (9) ◽  
pp. 1466-1471 ◽  
Author(s):  
R. A. Cunjak ◽  
E. M. P. Chadwick ◽  
M. Shears
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Significant Proportion ◽  
River Mouth ◽  
Northwest Coast ◽  
Total Production ◽  
Younger Age ◽  
Mean Size ◽  
Salmon Parr ◽  
Atlantic Salmon Parr

Downstream migrations and estuarine residence by Atlantic salmon (Salmo salar) parr and smolts were studied in a small river on the northwest coast of Newfoundland in 1983 and in 1987. There were large downstream migrations in the spring and small downstream migrations in the fall. The major differences between the two types of migrant were that parr migrated about 1 wk before smolts and at a younger age compared with smolts and while parr remained in the estuary throughout the summer, smoits did not. Modal age and mean size were less for parr sampled in the estuary compared with those sampled at the counting-fence which suggested that the smallest parr were not captured by the fence. The estuarine population of parr represented a significant proportion of the river's total production of salmon. Parr were found throughout the estuary in salinities up to 24 parts per thousand but were most abundant near the river mouth. There was evidence that larger parr became smolts and eventually migrated to sea, but smaller parr probably returned to the river for overwintering. It is clear that estuaries should be included as habitat used for rearing Atlantic salmon.

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