Effects of spawning distribution on juvenile Atlantic salmon (Salmo salar) density and growth

2011 ◽  
Vol 68 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Maxim A.K. Teichert ◽  
Anders Foldvik ◽  
Torbjørn Forseth ◽  
Ola Ugedal ◽  
Sigurd Einum ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Local Density ◽  
Habitat Characteristics ◽  
Individual Growth ◽  
Dominant Factor ◽  
Atlantic Salmon Salmo Salar ◽  
Local Densities ◽  
Spawning Sites

We test whether the spatial distribution of spawning sites in a natural population is related to the density and individual growth rate of juvenile stream-dwelling salmonids. For this purpose, fine-scale data on the spatial distribution of Atlantic salmon ( Salmo salar ) nest sites, juvenile densities and body size, and habitat characteristics were combined. The area of nests summed over reaches of 25 m in length was positively correlated with local young-of-the-year (YOY) densities and was the strongest predictor of local densities. In turn, increased YOY densities were related to slower growth, and YOY density was the strongest predictor of YOY size. Measured habitat variables had little effect on YOY density over the spatial scale examined, which suggests that redistribution of YOY salmon according to habitat preferences was limited. The distribution of spawning sites was therefore the best predictor of local densities and subsequently YOY growth. Thus, during the YOY stage when dispersal is limited, patchy spawning distributions combined with local density-dependence may be the dominant factor responsible for spatial variation in growth.

Effects of discharge and local density on the growth of juvenile Atlantic salmon Salmo salar

2010 ◽  
Vol 76 (7) ◽  
pp. 1751-1769 ◽  
Author(s):  
M. A. K. Teichert ◽  
E. Kvingedal ◽  
T. Forseth ◽  
O. Ugedal ◽  
A. G. Finstad
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Local Density ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon

Spatial distribution of Atlantic salmon (Salmo salar) breeders: among- and within-river variation and predicted consequences for offspring habitat availability

2010 ◽  
Vol 67 (12) ◽  
pp. 1993-2001 ◽  
Author(s):  
Anders Gravbrøt Finstad ◽  
Sigurd Einum ◽  
Leif Magnus Sættem ◽  
Bjart Are Hellen
Keyword(s):  
Spatial Distribution ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Early Life ◽  
Skewed Distribution ◽  
Habitat Availability ◽  
Life Stages ◽  
Early Life Stages ◽  
Juvenile Dispersal ◽  
Atlantic Salmon Salmo Salar

The spatial distribution of breeders within populations may have important implications for offspring habitat availability in species where mobility of early life stages is restricted. Here we address this issue using time series of spawner distributions from eight Norwegian Atlantic salmon ( Salmo salar ) populations. Whereas spawners distribute themselves uniformly along the length of the rivers in some populations, others show a heavily skewed distribution. Linear mixed models identified pronounced and temporally consistent among-population differences in spawner distributions. Using a model of limited juvenile dispersal from nests following emergence, we show that the observed spawner distributions are predicted to result in significant proportions of rivers being inaccessible for young of the year during early life stages, and the magnitude of this effect differs among populations (e.g., ranging from 27% to 59% for dispersal distance of 250 m). Thus, assuming population regulation during early but not later juvenile stages, consistent differences in spawner distributions among populations such as those observed here may translate into differences in productivity (i.e., carrying capacity) as well as egg densities required for populations to reach their spawning targets.

Spatial diffusion modelling of juvenile Atlantic salmon (Salmo salar) shows ontogenetic increase in movement rates

2017 ◽  
Vol 74 (2) ◽  
pp. 202-207 ◽  
Author(s):  
A. Foldvik ◽  
S. Einum ◽  
A.G. Finstad
Keyword(s):  
Spatial Distribution ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Continuous Distribution ◽  
Diffusion Models ◽  
Ontogenetic Changes ◽  
Ecological Processes ◽  
Breeding Sites ◽  
Atlantic Salmon Salmo Salar ◽  
The Individual

For organisms with extensive ontogenetic changes in phenotypes, knowledge of how movement of individuals changes throughout life is pivotal to understanding ecological processes. Here, we study the spatial distribution of a cohort of Atlantic salmon (Salmo salar) from hatching to their third summer of juvenile life, during which they go through a fourfold change in body size. The fish originated from three distinct breeding sites, and their distribution was mapped using electrofishing throughout the river at 10 sampling periods. The spatial distribution throughout ontogeny was analysed using diffusion models. The distribution changed from three distinct nonoverlapping distributions centred on the individual breeding sites at the early first summer stage to a single continuous distribution at the end of the study. The diffusion coefficient increased throughout ontogeny, and spatial distributions were well-described using diffusion models, explaining 46%–89% of the variation. This highlights the utility of diffusion models when considering spatial habitat structure both in conservation and research.

Spatial distribution correspondence of a juvenile Atlantic salmon Salmo salar cohort from age 0+ to 1+ years

2012 ◽  
Vol 81 (3) ◽  
pp. 1059-1069 ◽  
Author(s):  
A. Foldvik ◽  
M. A. K. Teichert ◽  
S. Einum ◽  
A. G. Finstad ◽  
O. Ugedal ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon

Spatial distribution and feeding in atlantic salmon, Salmo salar L. juveniles

1979 ◽  
Vol 14 (3) ◽  
pp. 239-247 ◽  
Author(s):  
J. W. J. Wankowski ◽  
J. E. Thorpe
Keyword(s):  
Spatial Distribution ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar

Density-dependent territory size and individual growth rate in juvenile Atlantic salmon (Salmo salar)

2014 ◽  
Vol 24 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Amanda A. Lindeman ◽  
James W. A. Grant ◽  
Cyndy M. Desjardins
Keyword(s):  
Growth Rate ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Individual Growth ◽  
Territory Size ◽  
Density Dependent ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Individual Growth Rate

Escalation of an asymmetric contest: mortality resulting from mate competition in Atlantic salmon, Salmo salar

1987 ◽  
Vol 65 (3) ◽  
pp. 766-768 ◽  
Author(s):  
Jeffrey A. Hutchings ◽  
Ransom A. Myers
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Mature Male ◽  
Mate Competition ◽  
Male Aggression ◽  
Dorsal Fin ◽  
Atlantic Salmon Salmo Salar ◽  
Mandibular Teeth ◽  
Mature Male Parr ◽  
Spawning Sites

Male anadromous Atlantic salmon, Salmo salar, fatally injured mature male parr during spawning. The wound consisted of three parallel cuts which exposed musculature on one side of the parr either directly below or immediately posterior to the base of the dorsal fin. The spacing of the cuts matched the spacing of the anadromous male's lingual and mandibular teeth. The wounding of parr in this manner is consistent with the observation of larger males vigorously shaking smaller males between their jaws. Mortality resulting from anadromous male aggression contributes to the low survival of mature male parr. Given the high mortality associated with parr maturation, if male parr must compete with anadromous males and other parr at all spawning sites, parr may be willing to risk escalated contests during mate competition with anadromous males to fertilize eggs.

Atlantic salmon (Salmo salar) smolt production: the relative importance of survival and body growth

2009 ◽  
Vol 66 (3) ◽  
pp. 471-483 ◽  
Author(s):  
Gregg E. Horton ◽  
Benjamin H. Letcher ◽  
Michael M. Bailey ◽  
Michael T. Kinnison
Keyword(s):  
Atlantic Salmon ◽  
New England ◽  
Salmo Salar ◽  
High Variability ◽  
Body Growth ◽  
Individual Growth ◽  
Relative Importance ◽  
Entire Study ◽  
Atlantic Salmon Salmo Salar ◽  
Cohort Differences

The complex life history of Atlantic salmon ( Salmo salar ) coupled with interacting abiotic and biotic factors leads to extreme demographic variability across the species’ range. Our goal was to evaluate the relative importance of survival and body growth in determining smolt production across space and time. We used passive integrated transponder tags and capture–mark–recapture analyses to estimate survival, emigration, and growth for six cohorts of presmolt Atlantic salmon in two streams (three cohorts per stream) in New England, USA. We observed remarkable among-cohort consistency in mean monthly survival during a 17-month period from age-0+ autumn to age-2+ spring yet high variability in monthly survival over shorter time intervals (seasons). Despite this latter variability, survival did not translate into among-cohort differences in proportions of age-2+ versus age-3+ smolts. Alternatively, the high variability across seasons and cohorts in mean individual growth rate did lead to differences in within-cohort proportions of age-2+ versus age-3+ smolts (regardless of stream). We conclude that in our two small study streams, variability in growth and size impacted smolt age and, ultimately, smolt production. Density-dependent effects on growth at the scale of the entire study site represent a possible mechanism underlying our observations.

Differentiation in juvenile growth and bimodality patterns between northern and southern populations of Atlantic salmon (Salmo salar L.)

1994 ◽  
Vol 72 (9) ◽  
pp. 1603-1610 ◽  
Author(s):  
Alfredo G. Nicieza ◽  
Felipe G. Reyes-Gavilán ◽  
Florentino Braña
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Growth Rates ◽  
Individual Growth ◽  
Late Winter ◽  
Southern Population ◽  
Northern Spain ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Modal Group

Juvenile Atlantic salmon, Salmo salar, from two contrasting populations that had been reared under identical conditions differed in freshwater growth rates and the development of bimodality in length–frequency distributions. Segregation by size started at least a month earlier in the northern (River Shin, northern Scotland) than in the southern population (River Narcea, northern Spain). Northern fish initially grew faster and entered the upper modal group at a larger size (about 100 mm) than did southern fish (about 90 mm). However, the percentage of fish in the upper modal group was greater for the southern population and they grew fastest over winter and during the spring leading up to smolting, and were larger at the smolt stage. By late winter, the individual growth rates of upper modal fish were inversely correlated with their body length in December. These results suggest the existence of genetic differences between populations in the expression of growth bimodality in juvenile Atlantic salmon. This may indicate that size and growth rate thresholds determining the developmental pathway associated with age at smolt metamorphosis may vary between populations as a function of both smolt size and expected growth opportunity during winter and spring.

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