Discordant phenotypic variation in sympatric resident and anadromous Atlantic salmon (Salmo salar) populations

1991 ◽  
Vol 69 (11) ◽  
pp. 2846-2852 ◽  
Author(s):  
R. R. Claytor ◽  
E. Verspoor
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Flow Conditions ◽  
Electrophoretic Variation ◽  
Morphometric Variation ◽  
Resident Population ◽  
Atlantic Salmon Salmo Salar ◽  
Local Water ◽  
Genetic Contributions ◽  
Two Populations

Sympatric but electrophoretically distinguishable resident and anadromous Atlantic salmon (Salmo salar) populations from Little Gull Lake, Newfoundland, were compared for meristic and morphometric variation. No morphometric differentiation was detected. As the two populations have similar juvenile rearing habitats, this result is consistent with the hypothesis that local water-flow conditions are important in determining morphometry. Meristic divergence is as great as that between regional North American stocks, and the Little Gull Lake resident population is significantly different from all other Newfoundland–Labrador populations. With our data we cannot separate environmental from genetic contributions to the mersitic divergences because spatially separate spawning locations coincide with temperature differences. Our results suggest that meristic, morphometric, and electrophoretic variation are likely to be congruent only by coincidence among Atlantic salmon populations and that these characteristics likely evolve independently.

The influence of temperature and life stage in shaping migratory patterns during the early marine phase of two Newfoundland (Canada) Atlantic salmon (Salmo salar) populations

2019 ◽  
Vol 76 (12) ◽  
pp. 2364-2376 ◽  
Author(s):  
Kristin Bøe ◽  
Michael Power ◽  
Martha J. Robertson ◽  
Corey J. Morris ◽  
J. Brian Dempson ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Life Stage ◽  
Movement Patterns ◽  
Thermal Conditions ◽  
Migration Routes ◽  
Atlantic Salmon Salmo Salar ◽  
Migratory Patterns ◽  
Local Water ◽  
Migratory Movements

Owing to the iteroparous nature of Atlantic salmon (Salmo salar), a seaward migrating cohort may consist of juveniles and adults that differ in size, maturity, experience, and in the motivation and consequences of migratory movements. Few studies have investigated the role of ontogeny in shaping intrapopulation variability in movement patterns among Atlantic salmon monitored under the same environmental conditions. This study contrasted the movements of smolts and kelts in two Canadian (Newfoundland) populations from marine entry through coastal embayments and quantified the influence of local water temperatures on movement patterns. Significant differences in migration routes, migration speed, and diel movements between smolts and kelts were present. Kelts generally displayed faster, more directed, and less nocturnal movements compared with smolts. Temperature influenced seaward movement positively, as well as the degree of diurnal movement. Prolonged nearshore residency by smolts and kelts in the two embayments was accompanied by a considerable improvement in ocean thermal conditions, hypothesized to promote open ocean entry during conditions favorable to migration performance.

Evidence of Adaptive Polygenic Variation Between Two Populations of Atlantic Salmon (Salmo salar) Native to Tributaries of the S. W. Miramichi River, N.B.

1981 ◽  
Vol 38 (3) ◽  
pp. 321-333 ◽  
Author(s):  
Brian E. Riddell ◽  
William C. Leggett ◽  
Richard L. Saunders
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Proximate Composition ◽  
Phenotypic Expression ◽  
Directional Selection ◽  
Heritable Variation ◽  
Body Morphology ◽  
Atlantic Salmon Salmo Salar ◽  
Two Populations ◽  
Polygenic Variation

Breeding experiments were conducted to test the hypothesis that spatial homeostasis in growth and proximate composition and geographic variation in body morphology and timing of migration in juvenile Atlantic salmon (Salmo salar) have an adaptive basis. The populations studied were Rocky Brook and Sabbies River, tributaries of the Southwest Miramichi River, New Brunswick. Growth rates and proximate composition were very similar in the two populations under hatchery conditions. Genetic contributions to homeostasis in these traits were largely additive. The phenotypic expression of migratory behavior and the genetic control of timing were not quantifiable. A genetic basis to interpopulation variation in body morphology was demonstrated. Progeny from Rocky Brook which exhibits higher flows had more fusiform bodies and longer fins than progeny from Sabbies River when reared under identical conditions. Heritable variation in morphology and a demonstrated directional selection for greater fin size in high velocity environments support the hypothesis that these traits are adaptive. Adaptive polygenic variation between local populations stresses the need to delineate stocks on a functional basis so that species can be managed without significant loss of fitness and/or depletion of genetic variation in natural populations.Key words: quantitative genetics, heritability, adaptation, morphology, growth, proximate composition, migration, Atlantic salmon, interdemic variation, directional selection

Selection of Microhabitat in Summer by Juvenile Atlantic Salmon (Salmo salar)

1987 ◽  
Vol 44 (1) ◽  
pp. 120-129 ◽  
Author(s):  
D. L. Morantz ◽  
R. K. Sweeney ◽  
C. S. Shirvell ◽  
D. A. Longard
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
The Body ◽  
Flow Conditions ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Salmon Fry ◽  
Study Sites ◽  
Selection Of ◽  
Atlantic Salmon Parr

This study was designed to define the microhabitats selected in summer by juvenile Atlantic salmon (Salmo salar). Curves were developed describing the preference of 880 young salmon for water velocity at the fish's position (nose velocity), mean water column velocity, total water depth, and stream substrate size. Study sites were chosen in six morphologically diverse streams in Nova Scotia and New Brunswick during 1982–84. Of the four variables measured, only nose velocity chosen by both fry and parr was not significantly different among years or rivers. Atlantic salmon fry (< 65 mm) most frequently selected nose velocities between 5 and 15 cm∙s−1, small parr (65–100 mm) between 5 and 25 cm∙s−1 and large parr (> 100 mm) between 5 and 35 cm∙s−1. Apparently, juvenile salmon utilized water depths and stream substrates which varied within tolerable limits according to their availability in conjunction with preferred water velocities. Significant differences in the body shape and size of the pectoral fin of Atlantic salmon parr in different rivers did not influence the selection of nose velocities within the range of flow conditions sampled.

Differences Between Two Populations of Landlocked Atlantic Salmon (Salmo salar) in Newfoundland

1969 ◽  
Vol 26 (6) ◽  
pp. 1585-1596 ◽  
Author(s):  
William C. Leggett ◽  
G. Power
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Gasterosteus Aculeatus ◽  
Fish Population ◽  
Oligotrophic Lake ◽  
Forage Fish ◽  
Atlantic Salmon Salmo Salar ◽  
Invertebrate Population ◽  
Two Populations ◽  
Sexually Mature

Differences in growth rates, longevity, fecundity, and time of spawning between two populations of landlocked Atlantic salmon (Salmo salar) in Newfoundland were attributed to food quality and quantity. Salmon in Flatwater Pond, an oligotrophic lake with a poor invertebrate population and no forage fish, grew slowly (145 mm at age 2+, 245 mm at age 5+), suffered high mortality (approximately 60% in males after age 2+ and in females after age 3+), had very low fecundity (an average of 153 eggs per female), and were sexually mature by late August. Salmon in Gambo Pond, an oligotrophic lake with a good invertebrate population and an ample forage fish population in the form of Gasterosteus aculeatus, grew more rapidly reaching 157 mm at age 2+, 367 mm by age 5+, and 437 mm by age 8+. Longevity of the Gambo Pond stock was greater than that of Flatwater Pond (39.6% of the Gambo sample were older than 4+ years compared with 3.2% for Flatwater Pond). Gambo Pond salmon are not sexually mature until October.Salmon in both lakes exhibited seasonal movement into deeper water when the surface warmed above 14 C. At Flatwater Pond this movement contributed to an early end to the growing season.Scale reading was found to be an unreliable method for determining past spawning activity. Spawning marks were found on only 1 of 17 females known to have spawned previously.

The status of Atlantic salmon (Salmo salar): populations and habitats

2004 ◽  
Vol 61 (12) ◽  
pp. 2267-2270 ◽  
Author(s):  
Daniel Boisclair
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Management Practices ◽  
Current Knowledge ◽  
Limiting Factors ◽  
Flow Conditions ◽  
Atlantic Salmon Salmo Salar ◽  
Nursery Habitats ◽  
The Status ◽  
Management And Conservation

The important decline of Atlantic salmon (Salmo salar) across its range during the past three decades, despite numerous management and conservation programmes, is an alarming index of the vulnerability of this species. The following series of papers was produced to summarize current knowledge on specific interactions between biotic and abiotic variables that may contribute to determine the survival of Atlantic salmon. Evaluation of the challenges encountered in spawning grounds (siltation, oxygenation), nursery habitats (substrate, trophic interactions), overwintering habitats (flow conditions, winter feeding opportunities), and coastal and oceanic environments (water temperature, predators, parasites) suggest that all habitats required by Atlantic salmon and all processes that occur in each habitat represent a critical link that allows this species to persist. Management practices employed during artificial fish selection, incubation, and stocking also affect the success of restoration efforts. Because limiting factors may change in time and because our ability to intervene in specific habitats may be minimal, the only strategy within our reach may be to continue gathering information about processes that determine the fragility of Atlantic salmon and, in the light of our findings, to implement scientifically sound actions where and when possible.

scholarly journals Stable isotopes reveal linkages between ocean climate, plankton community dynamics, and survival of two populations of Atlantic salmon (Salmo salar)

2012 ◽  
Vol 69 (5) ◽  
pp. 784-794 ◽  
Author(s):  
Clive N. Trueman ◽  
Kirsteen M. MacKenzie ◽  
Martin R. Palmer
Keyword(s):  
Stable Isotopes ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Community Dynamics ◽  
Plankton Community ◽  
Norwegian Sea ◽  
Ocean Climate ◽  
Atlantic Salmon Salmo Salar ◽  
Iceland Basin ◽  
Two Populations

Abstract Trueman, C. N., MacKenzie, K. M., and Palmer, M. R. 2012. Stable isotopes reveal linkages between ocean climate, plankton community dynamics, and survival of two populations of Atlantic salmon (Salmo salar). – ICES Journal of Marine Science, 69: 784–794. An 18-year record of stable isotopes from Atlantic salmon (Salmo salar) migrating to two different regions of the North Atlantic reveals climate-driven subdecadal variations. Time-series of carbon isotopes in one salmon stock, thought to feed in the Faroes/Iceland Basin area, show Subpolar Gyre (SPG) modal variability, which is not seen in fish feeding in the Norwegian Sea. At times of weak SPG circulation, when waters in the Iceland Basin are relatively warm, carbon isotope values are somewhat negative, suggesting possible changes in phytoplankton community structure. The fluctuations in plankton community dynamics suggested by the stable isotope values are coincident with fluctuations in the estimates of marine mortality in one sea-winter fish feeding in the Norwegian Sea, but not in those feeding in the Iceland Basin. Marine mortality in salmon feeding in the Iceland Basin is therefore likely to be more strongly influenced by factors other than bottom–up control. Time-series analysis of stable isotopes in consumer tissues provides information on the interaction between climate and ecosystem dynamics on the scale of individual stocks and cohorts.

Microstructure and texture of fresh and smoked Atlantic salmon, Salmo salar L., fillets from fish reared and slaughtered under different conditions

2001 ◽  
Vol 32 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Sjofn Sigurgisladottir ◽  
Margret S. Sigurdardottir ◽  
Helga Ingvarsdottir ◽  
Ole J. Torrissen ◽  
Hannes Hafsteinsson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar

Persistence of Orally Administered Salmonella enterica Serovars Agona and Montevideo in Atlantic Salmon (Salmo salar L.)

2005 ◽  
Vol 68 (7) ◽  
pp. 1336-1339 ◽  
Author(s):  
L. L. NESSE ◽  
T. LØVOLD ◽  
B. BERGSJØ ◽  
K. NORDBY ◽  
C. WALLACE ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Salmonella Enterica ◽  
Most Probable Number ◽  
Fish Feed ◽  
Internal Organs ◽  
Probable Number ◽  
Atlantic Salmon Salmo Salar ◽  
Gastric Intubation

The objective of our experiments was to study the persistence and dissemination of orally administered Salmonella in smoltified Atlantic salmon. In experiment 1, salmon kept at 15°C were fed for 1 week with feed contaminated with 96 most-probable-number units of Salmonella Agona per 100 g of feed and then starved for 2 weeks. Samples were taken from the gastrointestinal tract and examined for Salmonella 1, 2, 8, 9, 15, and 16 days after the feeding ended. In experiment 2, Salmonella Agona and Montevideo were separately mixed with feed and administered by gastric intubation. Each fish received 1.0 × 108, 1.0 × 106, or 1.0 × 104 CFU. The different groups were kept in parallel at 5 and 15°C and observed for 4 weeks. Every week, three fish in each group were sacrificed, and samples were taken from the skin, the pooled internal organs, the muscle, and the gastrointestinal tract and examined for the presence of Salmonella. The results from the two experiments showed that the persistence of Salmonella in the fish was highly dependent on the dose administered. Salmonella was not recovered from any of the fish that were fed for 1 week with the lowest concentration of Salmonella. In the fish given the highest dose of Salmonella, bacteria persisted for at least 4 weeks in the gastrointestinal tract as well as, to some extent, the internal organs. The present study shows that under practical conditions in Norway, the risk of Salmonella in fish feed being passed on to the consumer of the fish is negligible.

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