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.

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.

Effects of ice on behaviour of juvenile Atlantic salmon (Salmo salar)

2013 ◽  
Vol 70 (10) ◽  
pp. 1488-1497 ◽  
Author(s):  
Tommi Linnansaari ◽  
Richard A. Cunjak
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Nocturnal Activity ◽  
Atlantic Salmon Salmo Salar ◽  
Daytime Activity ◽  
Ice Conditions ◽  
Salmon Parr ◽  
Surface Ice ◽  
Ice Period ◽  
Atlantic Salmon Parr

The behaviour of Atlantic salmon (Salmo salar) parr was compared among three periods of winter (pre-ice period, PI; period of subsurface ice, SSI; period of surface ice, SI). Salmon parr remained nocturnal regardless of the ice conditions. The level of nocturnal activity was similar during PI and SI periods but was significantly reduced during the SSI period. Immobility was also highest during the SSI period, but was only partly attributable to salmon parr being trapped under ice. No differences in daytime activity among ice periods were observed. Two nocturnal movement tactics were observed: (i) “emerge–settle–return” and (ii) “emerge–move–return”. The tactics were used similarly during PI and SSI periods, but the “move” tactic was predominant during the SI period. Atlantic salmon parr showed a strong tendency to return to their “home stone” after a period of activity. Homing was reduced during the SSI period, but the distance moved to a new home stone was typically <10 m. In general, salmon parr were able to cope well with subsurface and surface ice.

Feeding by Hatchery-Reared and Wild Atlantic Salmon (Salmo salar) Parr in Streams

1979 ◽  
Vol 36 (11) ◽  
pp. 1408-1412 ◽  
Author(s):  
A. J. Sosiak ◽  
R. G. Randall ◽  
J. A. McKenzie
Keyword(s):  
Atlantic Salmon ◽  
Key Words ◽  
Salmo Salar ◽  
Food Selection ◽  
Stomach Contents ◽  
Stomach Fullness ◽  
Size Dependent ◽  
Atlantic Salmon Salmo Salar ◽  
Feeding Experience ◽  
Salmon Parr

Hatchery-reared Atlantic salmon (Salmo salar) parr were captured 1–3 mo after release in streams, along with wild parr from the same streams. Identification of their stomach contents showed total number of organisms and number of taxa per stomach were greater and there was a higher index of stomach fullness in wild than in hatchery parr resident ≤ 2 mo in a stream. Wild parr consumed more Brachycentridae, Hydroptilidae, Diptera, and Plecoptera than did hatchery parr, but sometimes less Odontoceridae and Heptageniidae. These differences may have arisen from size-dependent food selection, the effects of feeding experience, or possible microhabitat differences between wild and hatchery parr. Key words: salmon parr, hatchery-reared, wild, feeding

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.

Potential for dispersal of Gyrodactylus salaris (Platyhelminthes, Monogenea) by sea-running stages of the Atlantic salmon (Salmo salar): field and laboratory studies

1998 ◽  
Vol 55 (2) ◽  
pp. 507-514 ◽  
Author(s):  
Arnulf Soleng ◽  
Tor A Bakke ◽  
Lars P Hansen
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
River Mouth ◽  
Infected Fish ◽  
Surface Salinity ◽  
Wild Salmon ◽  
Atlantic Salmon Salmo Salar ◽  
Water Dispersal ◽  
Salmon Parr ◽  
Salmon Smolt

Population growth of Gyrodactylus salaris increased exponentially on Atlantic salmon (Salmo salar) smolts in laboratory experiments conducted at 12.0°C. Furthermore, G. salaris was transmitted successfully from salmon smolt to parr at 0.0, 7.5, 10.0, and 20.0%° salinity and reproduced in fresh water after direct transfer from 7.5%° (16 days), 20.0%° (4 and 8 h), and 33.0%° (5, 15, and 30 min). No G. salaris were observed on salmon parr exposed to 33.0%° for 60 min. The prevalence of G. salaris on wild salmon smolts caught approximately 25 km from the river mouth in the Drammensfjord (surface salinity 2.0-3.5%°) was 71.2% compared with 88.0% on those from the neighbouring River Lierelva. Adult wild salmon caught as prespawners, spawners, and postspawners (kelts) in the River Drammenselva were infected with G. salaris. The prevalence and abundance increased from autumn to spring, in contrast with earlier studies on salmon parr, demonstrating the possible importance of adult salmon as reservoirs for G. salaris during winter. The results support the hypothesis of brackish water dispersal of G. salaris by infected salmonids migrating in estuaries and fjords. The use of salt as a disinfectant against G. salaris in hatcheries, and the stocking of possibly infected fish into brackish and seawater, should also be reexamined.

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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