Relationship between Annual Recruitment and Density in a Lacustrine Population of Allopatric Brown Trout (Salmo trutta)

1992 ◽  
Vol 49 (6) ◽  
pp. 1107-1113 ◽  
Author(s):  
Reidar BorgstrØm
Keyword(s):  
Population Density ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Nursery Areas ◽  
Resident Population ◽  
Age Class ◽  
Brown Trout Salmo Trutta

The annual recruitment of brown trout (Salmo trutta) parr from stream nursery areas to an allopatric, lake-resident population was studied during a 5-yr period. The immigration of each cohort to the lake occurred over several years, but the data indicate that the duration of the lotic residence of parr may be regulated by the density of the lake population. At high lake population density, the number of brown trout in age-class 3+ present in the lake by June was low, while at low lake population density the number of 3+ fish increased substantially.

Population density of migratory and resident brown trout (Salmo trutta) in relation to altitude: evidence for a migration cost

2001 ◽  
Vol 70 (1) ◽  
pp. 112-121 ◽  
Author(s):  
T. Bohlin ◽  
J. Pettersson ◽  
E. Degerman
Keyword(s):  
Population Density ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Migration Cost ◽  
Brown Trout Salmo Trutta

Insights for planning an effective stocking program in anadromous brown trout (Salmo trutta)

2013 ◽  
Vol 70 (7) ◽  
pp. 1092-1100 ◽  
Author(s):  
Francisco Marco-Rius ◽  
Graciela Sotelo ◽  
Pablo Caballero ◽  
Paloma Morán
Keyword(s):  
Mhc Class Ii ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Economic Value ◽  
Brood Stock ◽  
Nursery Areas ◽  
Male Phenotype ◽  
Brown Trout Salmo Trutta ◽  
Mhc Locus ◽  
The Cost

Brown trout (Salmo trutta) is a salmonid species with a high socio-economic value related with recreational fishing. Because of that, stocking programs have been developed in many populations, although they have focused on resident populations. To explore which factors promote migratory behaviour when implementing stocking actions, 28 brown trout artificial crosses were carried out in a noncommercial hatchery, and the returning success of their offspring was further evaluated. Return rate was examined according to male phenotype (anadromous versus resident), mean egg size, parents’ similarity at major histocompatibility complex (MHC) class II β-gene, and stocking procedure. At the end of the experiment, 35 of the captured returning adults (9.4%) belonged to 14 of those crosses. Return success shows a significant effect (p = 0.0016) by parental MHC similarities, stocking procedure, and male phenotype. Our results indicate that planting fertilized eggs in nursery areas of the river, together with the selection of anadromous males as brood stock and mate pairs with higher similarity at the MHC locus, can be an appropriate option to increase the migratory part of trout populations. In addition, nursery areas can allow an important decrease in the cost per stocked individual, being 32 times less expensive than the cost per hatchery-reared individual.

NONLINEAR SELF-THINNING IN A STREAM-RESIDENT POPULATION OF BROWN TROUT (SALMO TRUTTA)

Ecology ◽  
2002 ◽  
Vol 83 (7) ◽  
pp. 1808-1816 ◽  
Author(s):  
Pedro A. Rincón ◽  
Javier Lobón-Cerviá
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Resident Population ◽  
Brown Trout Salmo Trutta

Introduction and extinction of brown trout (Salmo trutta L.) in an impoverished subantarctic stream

1992 ◽  
Vol 4 (1) ◽  
pp. 9-14 ◽  
Author(s):  
J. Cooper ◽  
J.E. Crafford ◽  
T. Hecht
Keyword(s):  
Brown Trout ◽  
Life Style ◽  
Salmo Trutta ◽  
Small Population ◽  
Marion Island ◽  
Resident Population ◽  
Brown Trout Salmo Trutta ◽  
Alien Fish

Brown trout were introduced to the Van den Boogaard River on subantarctic Marion Island in 1964, and a small population became established. The last individual was seen in 1984, and the species is now considered to be extinct on the island. Their diet was exclusively allochthonous, with snails and spiders predominating. Ages estimated at six to eleven years showed that spawning must have occurred since the original introduction. Since the Van den Boogaard River enters the sea via a waterfall, it is postulated that trout were not able to practice an anadromous life-style, and that this, as well as other factors connected with the impoverished nature of the stream, led to dwarfing of the resident population. No further introductions of alien fish to Marion Island should be contemplated.

Nonlinear Self-Thinning in a Stream-Resident Population of Brown Trout (Salmo trutta)

Ecology ◽  
2002 ◽  
Vol 83 (7) ◽  
pp. 1808 ◽  
Author(s):  
Pedro A. Rincon ◽  
Javier LoboN-Cervia
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Resident Population ◽  
Brown Trout Salmo Trutta

Effect of Population Density on Gillnet Catchability in Four Allopatric Populations of Brown Trout (Salmo trutta)

1992 ◽  
Vol 49 (8) ◽  
pp. 1539-1545 ◽  
Author(s):  
Reidar Borgstrøm
Keyword(s):  
Population Density ◽  
Brown Trout ◽  
Salmo Trutta ◽  
High Mountain ◽  
Catch Per Unit Effort ◽  
Power Functions ◽  
Trout Population ◽  
Brown Trout Salmo Trutta ◽  
Management Implication ◽  
Brown Trout Population

The gillnet catchability of allopatric brown trout (Salmo trutta) populations was studied in four Norwegian high-mountain lakes, with large differences in population densities. The number of fish and the length composition of the populations were estimated by mark–recapture. The catchability coefficient and the catch per unit effort were described by power functions, and the catchability was inversely related to number of fish present. An important fisheries management implication is that brown trout populations with low densities are more vulnerable to gillnets than populations with high densities. Furthermore, the use of gillnet catches as an estimator of brown trout population density will be biased.

Intracohort and intercohort spatial density dependence in juvenile brown trout (Salmo trutta)

2011 ◽  
Vol 68 (1) ◽  
pp. 115-121 ◽  
Author(s):  
Eli Kvingedal ◽  
Sigurd Einum
Keyword(s):  
Density Dependence ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Local Density ◽  
Spatial Density ◽  
Individual Response ◽  
Competitive Effects ◽  
Age Class ◽  
Brown Trout Salmo Trutta ◽  
Constrained Variation

An increased mobility with age can be expected for many organisms, which will reduce the potential for spatial density dependence. Here we quantify the extent of spatial density dependence for two juvenile age classes of brown trout ( Salmo trutta ) that differ in their dispersal abilities. As predicted, spatial variation in intracohort density had a strong effect on the performance of underyearlings, but not on yearlings. However, rather surprisingly, local underyearling density influenced the energetics of the older age class to the same extent as their own. Thus, yearlings do not appear to prioritize growth rate per se as a cue in movement decisions. The spatial patterns of densities and performance are consistent with older fish distributing themselves primarily according to preferred abiotic variables that also influence energetics. Such decisions would remove any relation between local density of their own age class and growth performance. However, because of competitive effects from the patchily distributed younger age class, spatial homogenization of competition intensities appears to be constrained. Variation in yearling body mass also increased with density of their own age class, indicating that even though the average effect of intracohort competition was absent, the individual response was asymmetric.

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