Changes in Mean Weight, Sea-Age Composition, and Catch-per-Unit-Effort of Atlantic Salmon (Salmo salar) Angled in the Godbout River, Quebec, 1859–1983

1986 ◽  
Vol 43 (2) ◽  
pp. 281-287 ◽  
Author(s):  
Alex T. Bielak ◽  
Geoffrey Power
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Age Groups ◽  
Fishing Effort ◽  
Commercial Fisheries ◽  
Catch Per Unit Effort ◽  
Age Composition ◽  
Atlantic Salmon Salmo Salar ◽  
The Mean ◽  
Selective Effects

A weight-age classification, based on recent catches, was retroactively applied to angled Atlantic salmon (Salmo salar) catches recorded in the log of the Godbout salmon club between 1859 and 1983. Over this period, numbers of salmon caught have fluctuated with a periodicity of 20–30 yr but catches have been maintained. There has been a big increase in fishing effort, and the proportion of two-sea-year to previously spawned fish has increased. The mean weight of these age groups has declined 0.005–0.009 kg∙yr−1. These changes are attributed to the selective effects of commercial fisheries on the stock.

Lake Use by Wild Anadromous Atlantic Salmon, Salmo salar, as an Index of Subsequent Adult Abundance

1986 ◽  
Vol 43 (1) ◽  
pp. 2-11 ◽  
Author(s):  
P. M. Ryan
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Seasonal Changes ◽  
Catch Per Unit Effort ◽  
Age Composition ◽  
Atlantic Salmon Salmo Salar ◽  
Spawning Areas ◽  
Population Sizes ◽  
Standing Waters ◽  
Adult Abundance

Atlantic salmon, Salmo salar, were censused each spring and fall for 5 or 6 yr in two lakes at the headwaters of the Gander River, Newfoundland. Density, biomass, and age varied seasonally and annually, ranging from 5.2 to 78.7 fish∙ha−1, 0.2 to 3.4 kg∙ha−1, and 1 to 7 yr, respectively. Seasonal changes in age composition were used to calculate net numbers and ages of fish moving into and out of the lakes. Population sizes typically increased from fall to spring as young fish moved into the lakes from downstream spawning areas and decreased from spring to fall as older fish moved downstream. The calculated net number of spring to fall emigrants over 6 yr was positively correlated (r = 0.835) with adult abundance (catch per unit effort) in the recreational fishery 1 yr later. The varying modal age of these emigrants was identical to the modal freshwater age of returning adults in each of four comparable years. Censusing of young Atlantic salmon in standing waters can be used to monitor smolt production and assist in prediction of the subsequent abundance of sea-run adults.

Effect of Sea-Age on the Reproductive Potential of Atlantic Salmon (Salmo salar) in Eastern Canada

1989 ◽  
Vol 46 (12) ◽  
pp. 2210-2218 ◽  
Author(s):  
R. G. Randall
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Reproductive Potential ◽  
Female Size ◽  
Eastern Canada ◽  
Age Composition ◽  
Atlantic Salmon Salmo Salar ◽  
Egg Deposition ◽  
Different Populations ◽  
Spawning Run

Reproductive potential of Atlantic salmon (Salmo salar), defined as average eggs per fish in the spawning run, varied three-fold both within stocks over time and among stocks from different geographic areas. Eggs per spawner is a function of fecundity, sea-age, proportion of females, and female size; the latter three traits varied significantly among years for salmon in both the Miramichi and Restigouche Rivers, New Brunswick. Because all of the above traits are related to sea-age at maturity, eggs per spawner was significantly correlated with mean sea-age in both rivers (R2 = 0.88 and 0.61, respectively). Among 10 different populations in eastern Canada, reproductive potential was also correlated with sea-age; for mean sea-ages (MSA) ranging from 1.0 to 1.8 yr, reproductive potential (RP) was defined by the power regression: RP = 1831.26 MSA1.30 (R2 = 0.64 P < 0.05). Thus reproductive potential can be estimated for any population for which the sea-age composition of spawners is known. Assuming a target egg deposition rate of 2.4 × 104 eggs per hectare, required spawners varied inversely with reproductive potential among the 10 populations, from five spawners (MSA = 1.75 yr) to 16 spawners (MSA = 1.15 yr) per hectare.

Activity of metabolic enzymes and muscle-specific gene expression in parr and smolts Atlantic salmon Salmo salar L. of different age groups

2017 ◽  
Vol 43 (4) ◽  
pp. 1117-1130 ◽  
Author(s):  
Maria V. Churova ◽  
Olga V. Meshcheryakova ◽  
Aleksey E. Veselov ◽  
Denis A. Efremov ◽  
Nina N. Nemova
Keyword(s):  
Gene Expression ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Age Groups ◽  
Metabolic Enzymes ◽  
Specific Gene ◽  
Specific Gene Expression ◽  
Atlantic Salmon Salmo Salar

Annual variation in size-selective mortality of Atlantic salmon (Salmo salar) fry

2001 ◽  
Vol 58 (6) ◽  
pp. 1187-1195 ◽  
Author(s):  
S P Good ◽  
J J Dodson ◽  
M G Meekan ◽  
D AJ Ryan
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Total Mortality ◽  
Weather Conditions ◽  
Fish Length ◽  
Selective Mortality ◽  
Atlantic Salmon Salmo Salar ◽  
Salmon Fry ◽  
Mean Size ◽  
The Mean

We investigated the size-selective mortality of Atlantic salmon (Salmo salar) fry during two consecutive summers that differed markedly in weather conditions. We sampled fry shortly after emergence in June and at the end of August to compare the distributions of back-calculated body size at hatching by examining otolith microstructure. Size-selective mortality was observed in both summers; however, the direction and strength of mortality differed. During the drought conditions of 1995, selective mortality was relatively weak and directed towards the smaller fry in the population. During the flood conditions of 1996, selective mortality was relatively strong and directed towards the larger fry of the same population. Interannual variability in size-selective mortality contributed to significant differences in the mean size of fry at the end of their first summer of life. Size-selective mortality rates estimated from the shifts in fish length at hatching observed during the first summer of life were comparable with published estimates of total mortality of Atlantic salmon fry, indicating that early mortality may be largely size selective. Mortality associated with hydroclimatic events can select against either small or large fish and is a key determinant of mean size attained by the end of the first summer of life.

Influence of Sea Temperature upon the Numbers of Grilse and Multi-Sea-Winter Atlantic Salmon (Salmo salar) Caught in the Vicinity of the River Dee (Aberdeenshire)

1985 ◽  
Vol 42 (9) ◽  
pp. 1513-1521 ◽  
Author(s):  
J. H. A. Martin ◽  
K. A. Mitchell
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
The Arctic ◽  
Average Weight ◽  
Regression Equations ◽  
Catch Per Unit Effort ◽  
Data Set ◽  
Sea Temperature ◽  
Atlantic Salmon Salmo Salar ◽  
High Seas

The possible influence of sea temperature upon the age of return of Atlantic salmon (Salmo salar) was examined using the catch and weight data of grilse and multi-sea-winter (MSW) salmon of the Aberdeen Harbour Board caught either within or adjacent to the River Dee (Aberdeenshire). This data set, apart from a 10-yr period of commercial confidentiality, is very suitable because uniformity of effort allowed catch per unit effort to be calculated. Only in the last few years was external pressure (high seas fishing) applied to the system. Various temperature series were examined but the known loci of high seas fishing and the temperature ranges involved suggested that the most relevant series is from the subarctic. Increase in temperature is shown to be associated with larger numbers of fish returning as MSW salmon and fewer as grilse. The average weight of grilse increases with grilse catch numbers. Regression equations for grilse and MSW salmon catch numbers are produced for the period 1877–1972. There is a marked 4-yr periodicity in the grilse catch data. A hypothesis is proposed that the temperature of the subarctic influences the migratory pattern, that fish travel further north into the Arctic/subarctic only during those years when the minimum temperature remains above 2 °C.

Fyke Net Catches as Indices of the Abundance of Brook Trout, Salvelinus fontinalis, and Atlantic Salmon, Salmo salar

1984 ◽  
Vol 41 (2) ◽  
pp. 377-380 ◽  
Author(s):  
P. M. Ryan
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Relative Abundance ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Catch Per Unit Effort ◽  
Small Lakes ◽  
Population Densities ◽  
Atlantic Salmon Salmo Salar ◽  
Fyke Nets

The catch per unit effort (CPUE) data of brook trout (Salvelinus fontinalis) and Atlantic salmon (Salmo salar) in fyke nets set in two small lakes in central Newfoundland were compared with population densities estimated with Schnabel multiple mark–recapture experiments each spring and fall from 1978 to 1982. The catchability of brook trout did not differ significantly between lakes or seasons, and CPUE was an index of the relative abundance of trout within and between lakes. In contrast, the catchability of Atlantic salmon differed greatly between lakes and varied seasonally, being greater in the spring but less in the fall than the catchability of brook trout. Comparisons of relative salmon abundance between lakes or of the relative abundance of brook trout to Atlantic salmon within or between lakes require a correction for seasonal differences in the catchability of salmon.

Effects of Oceanic Variations and the West Greenland Fishery on Age at Maturity of Icelandic West Coast Stocks of Atlantic Salmon (Salmo salar)

1989 ◽  
Vol 46 (1) ◽  
pp. 16-27 ◽  
Author(s):  
Dennis L. Scarnecchia ◽  
Árni Ísaksson ◽  
S. E. White
Keyword(s):  
Time Series ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
West Coast ◽  
Strongly Correlated ◽  
The West ◽  
West Greenland ◽  
Atlantic Salmon Salmo Salar ◽  
The Mean ◽  
Salmon Fishery

Investigations were conducted on the effects of oceanic variations (as measured by sea temperatures) and catches by the West Greenland salmon fishery on the sea age composition of Atlantic salmon (Salmo salar) stocks from 21 Icelandic west coast rivers. Annual ratios of grilse to two-sea-winter (2SW) salmon were strongly correlated among the 21 rivers. All eight rivers with time series extending back before the expansion of the West Greenland fishery showed lower ratios during the earlier period. Only 2 of the 21 rivers, however, had significantly declining ratios over their time series. In addition, for only one river was West Greenland catch significantly related to the ratios (P < 0.05), and for only one river did ratios increase when the expanded West Greenland fishery was active. Overall, the effects of the fishery on stock composition are evidently minimal. The mean April–May temperature when the smolts were to migrate out of rivers was significantly and positively related to subsequent ratios for five of the rivers, which, along with correlations among the ratios, indicated that more rapid growth of smolts in their first summer may have increased the ratios of grilse to 2SW salmon on several rivers.

scholarly journals Interannual changes in recruitment of the Atlantic salmon (Salmo salar) population in the River Oir (Lower Normandy, France): relationships with spawners and in-stream habitat

2005 ◽  
Vol 62 (4) ◽  
pp. 695-707 ◽  
Author(s):  
Jean-Luc Baglinière ◽  
Frédéric Marchand ◽  
Vincent Vauclin
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Survival Rates ◽  
Stream Habitat ◽  
Juvenile Salmon ◽  
Strongly Correlated ◽  
Data Set ◽  
Atlantic Salmon Salmo Salar ◽  
Salmon Population ◽  
The Mean

Abstract Since 1985, the dynamics of the Atlantic salmon (Salmo salar) population in the River Oir, a spawning tributary of the River Sélune (Lower Normandy, France), have been studied from a data set of parr density and the number and the age structure of migrating fish (smolts and adults). Parr densities (1.5–17.4 per 100 m2) and smolt production (0.25–9.2 per 100 m2) varied considerably from year to year. Migrating juveniles were mainly 1 year old. Abundance of parr and smolts was strongly correlated with 0+ densities. Egg-to-smolt survival rates were highly variable year on year (0.044–1.07%). During the juvenile freshwater phase, mortality was highest between the egg and the 0+ stage (97.5–99.9%). The fluctuations in abundance of juvenile salmon appear to be linked to the number and distribution of spawners within the stream during spawning, and also to the amount of silt deposition on the spawning beds. As a result, mortality was highest during the under-gravel phase, and the mean survival rate from egg to smolt was much lower than in rivers less impacted by human activities. Therefore, during the study period, the low production of smolts during some years might lead to a low renewal rate of the salmon population.

Atlantic Salmon (Salmo salar) Taken in the Sea in North Labrador

1975 ◽  
Vol 32 (2) ◽  
pp. 307-309
Author(s):  
G. Power ◽  
Douglas Cressman
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Commercial Fisheries ◽  
Scale Analysis ◽  
Northwest Atlantic ◽  
Atlantic Salmon Salmo Salar ◽  
Local Origin

Scale analysis showed that with few exceptions salmon taken near the northern extremity of Labrador were similar to stocks from Ungava rivers; those taken near Nain were probably of local origin. Knowledge of the distribution of local stocks of salmon in the sea contributes to our understanding of their migrations and is valuable in view of the recent development of commercial fisheries for this species in the northwest Atlantic.

Marine Growth of Atlantic Salmon (Salmo salar) in the Northwest Atlantic

1972 ◽  
Vol 29 (10) ◽  
pp. 1373-1380 ◽  
Author(s):  
K. Radway Allen ◽  
Richard L. Saunders ◽  
Paul F. Elson
Keyword(s):  
Growth Rate ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Growth Curve ◽  
Commercial Fisheries ◽  
The West ◽  
Northwest Atlantic ◽  
Atlantic Salmon Salmo Salar ◽  
Length Data ◽  
Preceding Winter

The fishery for Atlantic salmon in the west Greenland area has provided useful data for the study of marine growth of salmon. Length data from seaward migrating smolts, post-smolts, and 1-, 2-, and 3-sea-winter feeders taken at sea and 1-, 2-, and 3-sea-winter spawners taken by commercial fisheries, angling, and research traps, have been used to construct a tentative growth curve. Fish which spawned after 1 sea-winter (grilse) were smaller at the time of spawning than fish of the same smolt-class which had not matured but were still actively feeding at sea. Similarly, 2-sea-winter spawners were smaller than salmon which would not have returned until after a third sea winter. The growth rate of salmon during the summer prior to spawning was lower than that of fish which would have spawned a year or more later and appears to be about the same as that during the preceding winter.

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