Influence of Parr Maturity on Emigration of Smolting Atlantic Salmon (Salmo salar)

1989 ◽  
Vol 46 (3) ◽  
pp. 410-415 ◽  
Author(s):  
L P. Hansen ◽  
B. Jonsson ◽  
R. I. G. Morgan ◽  
J. E. Thorpe
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Sexual Maturity ◽  
Release Site ◽  
Atlantic Salmon Salmo Salar ◽  
Seaward Migration

Sexual maturity of parr reduces the probability of a future seaward migration. In release experiments in two separate years with Atlantic salmon in the Imsa River, Norway, immatures migrated sooner and in significantly higher proportions (P < 0.001) than did previously mature males. Furthermore, higher proportions of 2-yr olds than of 1-yr olds migrated, and 86–92% of the descent occurred at night. Large 2-yr olds migrated before smaller ones. Among those which did not migrate, some (3.2% of those released in 1986) were recaptured in the autumn, of which 91.9% were mature males. At Lussa, Scotland, 5.6 and 5.9% of smolting fish released in two separate years remained resident at the release site throughout the summer, and 91.8 and 93.4% of these matured in the autumn of the release year.

Imprinting and Homing of Atlantic Salmon (Salmo salar) Kelts

1989 ◽  
Vol 46 (4) ◽  
pp. 714-719 ◽  
Author(s):  
J. R. Foster ◽  
C. B. Schom
Keyword(s):  
Atlantic Salmon ◽  
New Brunswick ◽  
Salmo Salar ◽  
Release Site ◽  
Behavioral Changes ◽  
Salmon River ◽  
Delayed Release ◽  
Atlantic Salmon Salmo Salar ◽  
Seaward Migration ◽  
Passamaquoddy Bay

Experiments were conducted to determine if a process similar to imprinting occurs during each seaward migration of Atlantic Salmon (Salmo salar). Displaced Atlantic salmon kelts homed to the site from which they had previously emigrated to sea as smolts (Big Salmon River, New Brunswick, Canada) and did not home to their release sites, or their overwintering sites 150 km away. Delaying release of kelts past the time of normal seaward migration did not cause the behavioral changes associated with interference of the imprinting process described for smolts. Delayed release kelts did not remain near their seawater or estuarine release sites, home to their release sites, or non-selectively home to suitable spawning streams near their release sites. Delayed released kelts travelled away from the release site faster than kelts released during their normal time of seaward migration, but they did not return either to Passamaquoddy Bay or their natal stream in the calendar year of their release (the normal time for this stock) or in subsequent years.

Smolt development and subsequent sexual maturity in previously mature male Atlantic salmon (Salmo salar)

Aquaculture ◽  
1994 ◽  
Vol 121 (1-3) ◽  
pp. 79-93 ◽  
Author(s):  
R.L. Saunders ◽  
P.R. Harmon ◽  
D.E. Knox
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Sexual Maturity ◽  
Mature Male ◽  
Atlantic Salmon Salmo Salar

Age at Sexual Maturity in Icelandic Stocks of Atlantic Salmon (Salmo salar)

1983 ◽  
Vol 40 (9) ◽  
pp. 1456-1468 ◽  
Author(s):  
Dennis L. Scarnecchia
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Sexual Maturity ◽  
Physical Factors ◽  
Thermal Gradients ◽  
Ocean Temperature ◽  
Growth And Survival ◽  
Atlantic Salmon Salmo Salar ◽  
Life History Pattern ◽  
Second Year

For Icelandic stocks of Atlantic salmon (Salmo salar) in 77 rivers, the combination of June ocean temperature, length of river ascended by the salmon, discharge of the river in July–September, and latitude explained much of the variation in percentages of grilse — 72% for females and 62% for males. For both sexes, percentage of grilse was directly related to ocean temperature but inversely related to length of river, discharge of river, and latitude. For stocks in 23 Southwest Coast rivers, length of river explained 72% of the variation in percentage of females that were grilse. Females in stocks south of the thermal gradients separating Atlantic from Arctic or Polar water tended to return as grilse; females north of the gradients tended to return after more than one winter at sea. The decline in percentages of grilse clockwise from southwestern to northeastern rivers corresponded closely with the decline in June ocean temperatures between these areas. I hypothesize that the salmon stocks have adapted their age at sexual maturity to the length and discharge of the rivers, natural mortality rates during their second year at sea, and average expected ocean temperatures, reflecting conditions for growth and survival, that the smolts encounter. Age at maturity appears not to be a direct causal response to any of these physical factors, and appears best understood only with reference to the entire life history pattern of each stock.

Sexual maturity increases mobility and heterogeneity in individual space use in Atlantic salmon ( Salmo salar ) parr

2020 ◽  
Vol 96 (4) ◽  
pp. 925-938
Author(s):  
Colin Bouchard ◽  
Frédéric Lange ◽  
François Guéraud ◽  
Jacques Rives ◽  
Cédric Tentelier
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Sexual Maturity ◽  
Space Use ◽  
Atlantic Salmon Salmo Salar

scholarly journals Horizontal movements of simulated escaped farmed Atlantic salmon (Salmo salar) in a western Norwegian fjord

2010 ◽  
Vol 67 (6) ◽  
pp. 1206-1215 ◽  
Author(s):  
Ove T. Skilbrei ◽  
Jens Christian Holst ◽  
Lars Asplin ◽  
Stein Mortensen
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Release Site ◽  
Fishing Effort ◽  
Fish Farms ◽  
Large Area ◽  
Atlantic Salmon Salmo Salar ◽  
Norwegian Fjord ◽  
Time Of Year ◽  
Farmed Atlantic Salmon

Abstract Skilbrei, O. T., Holst, J. C., Asplin, L., and Mortensen, S. 2010. Horizontal movements of simulated escaped farmed Atlantic salmon (Salmo salar) in a western Norwegian fjord. – ICES Journal of Marine Science, 67: 1206–1215. The dispersal of simulated escaped farmed Atlantic salmon (Salmo salar) in Hardangerfjord in western Norway was studied by telemetry. Tagged fish were released from fish farms on five different dates in the course of 1 year. Irrespective of the time of year, the fish dispersed rapidly, with a mean displacement from the release site of 5–7 km after 1 d, and 9–12 km after 2 d. Individual rates of movement varied, but were much higher than the rate of displacement from the release site, as fish moved around in the fjord basin in all directions. As a result, the fish were spread over an area of more than 500 km2 after 1 week. The number of released fish recorded in the fjord gradually declined after each release from ∼40% remaining in the fjord after 3 weeks to few or none after 7 weeks. In all, 38% moved out of the fjord, and 36 and 2% were reported as captured inside and outside the fjord, respectively. Their rapid dispersal suggests that concentrating efforts to recapture escaped salmon in the proximity of an escape site will probably not be successful, at least from locations of this type. In fact, the recaptures demonstrate that it is both necessary and possible to expand the fishing effort to cover a large area and to sustain it for several weeks to attain high rates of recapture. The wide dispersal of escaped fish potentially acting as vectors within the fjord basin also has implications for the spread of disease and parasites.

Effects of freshwater hyperoxia and hypercapnia and their influences on subsequent seawater transfer in Atlantic salmon (Salmo salar) smolts

2000 ◽  
Vol 57 (10) ◽  
pp. 2054-2064 ◽  
Author(s):  
C J Brauner ◽  
M Seidelin ◽  
S S Madsen ◽  
F B Jensen
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Cell Damage ◽  
Respiratory Acidosis ◽  
Release Site ◽  
Strong Ion Difference ◽  
Atlantic Salmon Salmo Salar ◽  
Muscle Water Content ◽  
Muscle Water ◽  
Gill Function

Atlantic salmon (Salmo salar) presmolts, smolts, and postsmolts compensate for a respiratory acidosis associated with 96 h of exposure to hyperoxia (100% O2; hO2), hypercapnia (2% CO2 and 98% air; hCO2), and combined hO2/hCO2 in freshwater (FW) by increasing strong ion difference, predominantly through a reduction in plasma [Cl-] (presumably via branchial Cl-/HCO3- exchange). In smolts, compensation during hO2 or hCO2 occurred within 24 h, whereas that in combined hO2/hCO2 was much slower, resulting in 33% mortality by 96 h. FW hO2 and combined hO2/hCO2 appeared to impair gill function, likely through oxidative cell damage. This resulted in reduced hypoosmoregulatory ability following subsequent transfer to seawater (SW), as indicated by changes in plasma ion levels, osmolality, and muscle water content, resulting in considerable mortalities. Interestingly, FW hCO2 appeared to enhance hypoosmoregulatory ability during subsequent SW transfer. Smolts are often transported from FW to a subsequent SW release site, and these data indicate that care should be taken to minimize the degree of hyperoxia experienced by the smolts. Hypercapnia, which results from metabolic CO2 production and inadequate water aeration, does not impair SW transfer, provided it does not occur in conjunction with hyperoxia.

Effects of continuous additional light on growth and sexual maturity in Atlantic salmon, Salmo salar, reared in sea cages

Aquaculture ◽  
2000 ◽  
Vol 191 (4) ◽  
pp. 337-349 ◽  
Author(s):  
Hans Peter Endal ◽  
Geir Lasse Taranger ◽  
Sigurd O Stefansson ◽  
Tom Hansen
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Sexual Maturity ◽  
Atlantic Salmon Salmo Salar

scholarly journals Basin-scale phenology and effects of climate variability on global timing of initial seaward migration of Atlantic salmon (Salmo salar)

2013 ◽  
Vol 20 (1) ◽  
pp. 61-75 ◽  
Author(s):  
Jaime Otero ◽  
Jan Henning L'Abée-Lund ◽  
Ted Castro-Santos ◽  
Kjell Leonardsson ◽  
Geir O. Storvik ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Climate Variability ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar ◽  
Basin Scale ◽  
Seaward Migration

Prediction of Angler Success in an Atlantic Salmon, Salmo salar, Fishery Two Fishing Seasons in Advance

1986 ◽  
Vol 43 (12) ◽  
pp. 2531-2534 ◽  
Author(s):  
Patrick M. Ryan
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Catch Per Unit Effort ◽  
Atlantic Salmon Salmo Salar ◽  
Unit Effort ◽  
Seaward Migration

The number of young Atlantic salmon, Salmo salar, in the spring in two lakes at the headwaters of the Gander River, Newfoundland, was positively correlated (r = 0.99) with the number of smolts in the subsequent seaward migration over a 5-yr period. Angler success (catch per unit effort) in the grilse fishery on the Gander River over a 7-yr period was positively correlated (r = 0.81) with the number of young in the lakes prior to the opening of the angling season of the previous year. Measures of the abundance of young salmon in freshwaters prior to the smolt run can be used to predict the size of the smolt run and allow for compensatory modifications to the adult fishery a year in advance of acticipated low adult returns.

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