Small-scale dispersal and population structure in stream-living brown trout (Salmo trutta) inferred by mark–recapture, pedigree reconstruction, and population genetics

2012 ◽  
Vol 69 (9) ◽  
pp. 1513-1524 ◽  
Author(s):  
Leif Asbjørn Vøllestad ◽  
Dimitar Serbezov ◽  
Arthur Bass ◽  
Louis Bernatchez ◽  
Esben Moland Olsen ◽  
...  
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Isolation By Distance ◽  
Juvenile Fish ◽  
Age Groups ◽  
Small Scale ◽  
Mark Recapture ◽  
Small Stream ◽  
Brown Trout Salmo Trutta ◽  
Mature Fish

Many animals move among habitats, and even small-scale dispersal of individuals between habitat patches may have strong implications for population dynamics and structure. Here, we use long-term mark–recapture data combined with extensive genotyping and parentage assignment to investigate the importance of small-scale location change of resident brown trout ( Salmo trutta ) in a small stream (1500 m). During the first summer, juvenile fish dispersed downstream (mean displacement 200 m), with smaller juveniles dispersing longer distances. Downstream movement was also predominant during the first winter, but older fish moved little. This limited dispersal resulted in a significant isolation-by-distance structure for ages 1 and 2, but not for older age groups or for the mature fish. Individual pairwise relatedness coefficients decreased with waterway distance for mature fish during the 2002 and 2003 spawning seasons, but only weakly. Overall, between-site genetic differentiation was stronger for the younger age classes, and the signal decayed with age, indicating that the genetic structure observed in the stream is mainly driven by spatial aggregation of close relatives.

Unidirectional Natural Hybridization between Brown Trout (Salmo trutta) and Atlantic Salmon (S. salar) in Newfoundland

1992 ◽  
Vol 49 (9) ◽  
pp. 1953-1958 ◽  
Author(s):  
Colin McGowan ◽  
William S. Davidson
Keyword(s):  
Atlantic Salmon ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Dna Analysis ◽  
Juvenile Fish ◽  
Natural Hybridization ◽  
Major Influence ◽  
Isolating Mechanisms ◽  
Brown Trout Salmo Trutta ◽  
Sexually Mature

Protein electrophoresis and mitochondrial DNA analysis were used to detect the frequency and direction of natural hybridization between brown trout (Salmo trutta) and Atlantic salmon (S. salar) in nine Newfoundland rivers. In total, 37 hybrids were discovered in a sample of 792 juvenile fish for a regional frequency of 4.67%. Local frequencies ranged from 0.00 to 18.75% and were significantly heterogeneous. All of the hybrids sampled were produced from matings between female brown trout and male Atlantic salmon. Possible reasons for the breakdown of prereproductive isolating mechanisms between these species are considered. Reproductive characteristics of the populations involved appear to have a major influence on the dynamics of hybridization between these species in Newfoundland. It is proposed that an abundance of sexually mature Atlantic salmon parr in Newfoundland streams is responsible for both the frequency and direction of hybridization observed in this study.

Competition among juvenile brown trout, grayling and landlocked Atlantic salmon in flumes - predicting effects of interspecific interactions on salmon reintroduction success

2020 ◽  
Author(s):  
Anna Hagelin ◽  
Eva Bergman
Keyword(s):  
Atlantic Salmon ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Interspecific Interactions ◽  
Juvenile Fish ◽  
Active Species ◽  
Major Interest ◽  
Brown Trout Salmo Trutta ◽  
Riverine Habitats ◽  
Juvenile Brown Trout

Abstract Worldwide declines in salmonid populations have generated major interest in conservation and restoration of wild populations and riverine habitats. Species reintroductions to previous habitats raises questions about their potential impact on these systems. In River Klarälven, landlocked Atlantic salmon (Salmo salar) has been extinct from upper reaches for over 50 years due to hydropower dams. Here we study competitive interactions between salmon, grayling (Thymallus thymallus) and brown trout (Salmo trutta), that occur in the upper reaches of the river. We examine foraging rates, aggression and activity of juvenile fish in allopatry at three different densities and in sympatry with one or both potential competitors in laboratory flumes. Salmon captured prey less frequently in the presence of brown trout and grayling, whereas grayling and brown trout were unaffected by salmon, but affected each other. Grayling was the most aggressive and active species whereas salmon the least. Consequently, re-introduction of salmon probably will have little impact on grayling and brown trout, whereas grayling and brown trout could affect the success of re-introducing salmon.

The impact of introduced pike (Esox lucius L.) on allopatric brown trout (Salmo trutta L.) in a small stream

Hydrobiologia ◽  
2014 ◽  
Vol 744 (1) ◽  
pp. 223-233 ◽  
Author(s):  
Trygve Hesthagen ◽  
Odd T. Sandlund ◽  
Anders G. Finstad ◽  
Bjørn O. Johnsen
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Esox Lucius ◽  
Small Stream ◽  
Pike Esox Lucius ◽  
Brown Trout Salmo Trutta ◽  
The Impact

Probability of First Sexual Maturation of Male Parr in Wild Sea-run Brown Trout (Salmo trutta) Depends on Condition Factor 1 yr in Advance

1994 ◽  
Vol 51 (9) ◽  
pp. 1920-1926 ◽  
Author(s):  
Torgny Bohlin ◽  
Claes Dellefors ◽  
Ulo Faremo
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Condition Factor ◽  
Mature Male ◽  
Small Stream ◽  
Late Autumn ◽  
Passive Integrated Transponders ◽  
Brown Trout Salmo Trutta ◽  
Mature Male Parr ◽  
Electric Fishing

In three years, in late autumn, underyearling wild sea-run brown trout (Salmo trutta) in a small stream were captured with electric fishing and tagged with microchips (passive integrated transponders). They were recaptured during the following season either as migrating smolts in a trap or by electric fishing in the stream just after the migration period and during spawning (late autumn). At spawning, they were distinguished as sexually mature male parr or immature juveniles. The smolts were longer and heavier at tagging than the mature male parr and the immature parr, which were similar in initial length and weight. The mature male parr had a significantly higher condition factor at tagging than the immature parr. The probability of parr maturation was positively associated with initial condition factor but not with initial body length. Growth of mature male parr and immature parr was similar in the early season but higher for immature parr in the late season. The result indicated that the choice of strategy was made earlier in life than previously recognized.

scholarly journals Influence of discharge, hydraulics, water temperature, and dispersal on density synchrony in brown trout populations (Salmo trutta)

2016 ◽  
Vol 73 (3) ◽  
pp. 319-329 ◽  
Author(s):  
Victor Bret ◽  
Benjamin Bergerot ◽  
Hervé Capra ◽  
Véronique Gouraud ◽  
Nicolas Lamouroux
Keyword(s):  
Water Temperature ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Age Groups ◽  
Negative Influence ◽  
Spawning Period ◽  
Emergence Period ◽  
Discharge Water ◽  
Brown Trout Salmo Trutta ◽  
Influence Of Substrate

Environmental factors may cause synchronous density variations between populations. A better understanding of the processes underlying synchrony is fundamental to predicting resilience loss in metapopulations subject to environmental change. The present study investigated the determinants of synchrony in density time series of three age groups of resident brown trout (Salmo trutta) (0+, 1+, and adults) in 36 stream reaches. A series of Mantel tests were implemented to disentangle the relative effects on trout synchrony of geographical proximity, environmental synchrony in key environmental variables affecting trout dynamics (discharge, water temperature, hydraulics, and spawning substrate mobility), and density-dependent dispersal. Results indicated that environmental synchrony strongly explained trout synchrony over distances less than 75 km. This effect was partly due to a negative influence on 0+ trout of strong discharges during the emergence period and a more complex influence of substrate mobility during the spawning period. Dispersal between reaches had a weak influence on results. Juvenile and adult densities were strongly driven by survival processes and were not influenced by environmental synchrony. The results suggest that the environment can have general effects on population dynamics that may influence the resilience of metapopulations.

Winter Habitat Utilization by Stream Resident Brook Trout (Salvelinus fontinalis) and Brown Trout (Salmo trutta)

1986 ◽  
Vol 43 (10) ◽  
pp. 1970-1981 ◽  
Author(s):  
Richard A. Cunjak ◽  
Geoffrey Power
Keyword(s):  
Brown Trout ◽  
Brook Trout ◽  
Salmo Trutta ◽  
Salvelinus Fontinalis ◽  
Focal Point ◽  
Age Groups ◽  
Habitat Utilization ◽  
Point Sources ◽  
Energetic Cost ◽  
Brown Trout Salmo Trutta

Habitat utilization by brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) is described from three winters of underwater observations in a southern Ontario river. Older trout (>age 1) generally occupied positions in deeper and faster water than age 0+ trout. In winter, at sites of sympatry, brown trout occupied greater focal point water depths than brook trout; both species had similar focal point water velocities. At all sites, and for both age groups and species, there was a strong preference for positions beneath cover. Relative to summer, trout positions in winter were characterized by slower water velocities and greater overhead cover, In winter, most trout were in aggregations, usually in pools beneath cover and close to point sources of groundwater discharge. Gregarious behaviour appeared to increase as water temperatures decreased; no such relationship was evident in the summer. Specific strategies for overwintering varied between sites and age groups but generally conformed to the theory of energetic cost minimization for position choice. These variable patterns appear to be adaptive.

scholarly journals Brown trout (Salmo trutta) growth and condition along a winter thermal gradient in temperate streams

2017 ◽  
Vol 74 (1) ◽  
pp. 56-64 ◽  
Author(s):  
W.E. French ◽  
B. Vondracek ◽  
L.C. Ferrington ◽  
J.C. Finlay ◽  
D.J. Dieterman
Keyword(s):  
Water Temperature ◽  
Brown Trout ◽  
Thermal Regime ◽  
Salmo Trutta ◽  
Stream Water ◽  
Juvenile Fish ◽  
Late Winter ◽  
Caloric Density ◽  
Significant Difference ◽  
Brown Trout Salmo Trutta

Winter harshness and the degree to which it can impact stream-dwelling salmonid populations has received considerable attention from fisheries biologists, although some debate exists regarding the importance of winter severity for local populations. Groundwater input may buffer stream water temperature and benefit fish in buffered versus unbuffered streams. Overwinter growth and condition of individual brown trout were measured in 24 groundwater-dominated streams, and the relations between winter growth and condition to stream thermal regime (quantified by regressions of air and water temperature) and diet quality (amount and caloric density of prey) were examined in a subset of 16 streams. Brown trout (Salmo trutta) growth rate (mg·g−1·day−1) was positive overwinter in 18 of 24 streams, and there was no significant change in condition between early and late winter. Juvenile fish grew faster than adults, but there was no significant difference in condition between adults and juveniles. Thermal regime positively influenced winter growth for both adults and juveniles, likely mediated through moderation of water temperature by groundwater, whereas diet had no significant effect on growth.

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