Cross-tributary analysis of parr to smolt recruitment of Atlantic salmon (Salmo salar)

2000 ◽  
Vol 57 (8) ◽  
pp. 1607-1616 ◽  
Author(s):  
Kevin G Whalen ◽  
Donna L Parrish ◽  
Martha E Mather ◽  
James R McMenemy
Keyword(s):  
Atlantic Salmon ◽  
Density Dependence ◽  
Linear Function ◽  
Salmo Salar ◽  
Population Level ◽  
The West ◽  
Atlantic Salmon Salmo Salar ◽  
Mature Parr ◽  
Recruitment Variability ◽  
Level Effect

We used estimates of Atlantic salmon (Salmo salar) parr and smolt density, estimated in three tributaries of the West River, Vermont, U.S.A., to determine (i) if smolt recruitment is density dependent or independent of parr density, (ii) if the proportion of parr migrating as smolts and cohort survival differ among tributaries, and (iii) the effect of parr maturity on smolt production and recruitment variability. We found that parr to smolt recruitment was best described with a linear function providing no evidence for density dependence in the recruitment dynamics of parr and smolts at the tributary scale. The proportion of age-1 parr recruiting to age-2 smolts did not systematically differ among tributaries or years (overall mean ± 95% CL: 18 ± 11%, range = 9-37%), and mean age-1 to age-2 survival ranged less than twofold among tributaries (27-46%) and was independent of cohort density. Survival of age-1 mature (39%) and immature (33%) parr was similar, but probability of smolting for mature parr (0.21) was threefold less than for immature parr (0.76). Quantifying smolt recruitment pathways involving parr maturation helped elucidate the population-level effect of parr maturation on smolt production and recruitment variability.

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.

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.

Energy allocation among developmental stages, age groups, and types of Atlantic salmon (Salmo salar) spawners

2003 ◽  
Vol 60 (5) ◽  
pp. 506-516 ◽  
Author(s):  
Nina Jonsson ◽  
Bror Jonsson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Developmental Stages ◽  
Energy Content ◽  
Energy Allocation ◽  
Gonadal Development ◽  
Power Functions ◽  
Allocation Pattern ◽  
Atlantic Salmon Salmo Salar ◽  
Mature Parr

Relationships between energy density (kJ·100 g–1) and body length (mm), which varied between life-history stages of Atlantic salmon (Salmo salar), were described by power functions. The variation was chiefly caused by differences in lipid concentrations. Energy densities of maturing and rematuring parr were higher than those of similarly aged smolts. Monthly specific growth rate was higher in maturing parr than in salmon at sea. Mature parr males allocated relatively more energy to gonadal development and less to soma development than anadromous males. Spawning expenditure increased from 34 to 53% for 55- to 72-cm-long females. In males, similar losses were from 47 to 49% of their total energy content at river entry. More energy was used in reproduction in a long river than in a short one. Male allocation to gonads relative to soma was highest in the shorter river. Energy allocation pattern varied among developmental stages. Very energy-rich male parr rematured in subsequent years without going to sea; less energy-rich ones smolted and migrated to sea.

Discrimination between Atlantic Salmon (Salmo salar) of North American and European Origin using Restriction Analyses of Mitochondrial DNA

1991 ◽  
Vol 48 (5) ◽  
pp. 884-893 ◽  
Author(s):  
Eldredge Bermingham ◽  
Stephen H. Forbes ◽  
Kevin Friedland ◽  
Carles Pla
Keyword(s):  
Mitochondrial Dna ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
North American ◽  
Restriction Endonucleases ◽  
The West ◽  
European Origin ◽  
West Greenland ◽  
Atlantic Salmon Salmo Salar ◽  
The North

Twenty restriction endonucleases were used to study mitochondrial DNA (mtDNA) polymorphism in 11 hatchery strains of Atlantic salmon (Salmo salar) representing geographically separated populations in Europe and North America. The North American salmon mtDNAs studied were readily distinguished, by a minimum of seven restriction site differences, from fish of European origin. These results suggested that restriction analyses of mtDNA might provide a useful method for determining the proportions of European and North American Atlantic salmon caught in the West Greenland fishery. To test this proposition, we analyzed 328 salmon caught in the 1987 West Greenland fishery including 68 fish with coded wire or Carlin tags which provided the geographic source of the tagged salmon. We correctly identified the continent of origin for 67 of the 68 physically tagged salmon using two informative restriction endonucleases. This study provides a clear indication of the usefulness of mtDNA for discriminating between European and North American Atlantic salmon caught in the West Greenland fishery and for mixed-fishery analysis in general.

Forecasting Yields of Two-Sea-Winter Atlantic Salmon (Salmo salar) from Icelandic Rivers

1984 ◽  
Vol 41 (8) ◽  
pp. 1234-1240 ◽  
Author(s):  
Dennis L. Scarnecchia
Keyword(s):  
Atlantic Salmon ◽  
Density Dependence ◽  
Salmo Salar ◽  
Critical Period ◽  
Statistical Tests ◽  
First Year ◽  
Regression Equations ◽  
Predictive Regression ◽  
Atlantic Salmon Salmo Salar ◽  
Linear Relationships

To forecast yields of two-sea-winter Atlantic salmon (Salmo salar) from 15 Icelandic rivers, I developed predictive regression equations based on yields of grilse of the same smolt class harvested in the previous year. The relationships were positive and significant (P < 0.05) for all rivers. The logarithm of grilse catch explained 25–85% of the variation in logarithm of two-sea-winter salmon catch the following year. Inasmuch as statistical tests for linearity between the variables were difficult to interpret and showed conflicting conclusions, I consider them inadequate for assessing whether density dependence occurs between grilse and two-sea-winter salmon. Linear or near linear relationships, which imply no density dependence, appear to occur between log grilse and log two-sea-winter salmon yields. The critical period determining run size from a given escapement thus occurs either during the freshwater rearing phase or during the first year the salmon are at sea.

Effect of maturation on parr growth and smolt recruitment of Atlantic salmon

1999 ◽  
Vol 56 (1) ◽  
pp. 79-86 ◽  
Author(s):  
Kevin G Whalen ◽  
Donna L Parrish
Keyword(s):  
Atlantic Salmon ◽  
Spatial Scale ◽  
Salmo Salar ◽  
Individual Growth ◽  
Connecticut River ◽  
Atlantic Salmon Salmo Salar ◽  
Mature Parr ◽  
Negative Effect ◽  
Broad Spatial Scale

We determined the effect of maturation on parr growth and smolt recruitment of Atlantic salmon (Salmo salar) stocked in Vermont tributaries of the Connecticut River. Both among and within tributaries, mature parr ranged between 28 and 52% of the age-1 parr collected and up to 67% of the age-2 parr collected. Percent age-1 parr maturing in October-November was positively related to mean length the preceding June. In October-November, immature age-1 parr were greater in mean length than age-1 mature parr. Data from parr individually tagged in June and recaptured in October showed immature parr exhibited twofold greater individual growth than maturing parr. Smolt recruitment was highly dependent upon state of maturity the preceding fall; fewer individuals that matured as parr recruited to smolt compared with parr remaining immature. Our study shows, over a broad spatial scale, that variation in incidence of maturation is largely explained by parr size among tributaries and river reaches and, furthermore, empirically demonstrates a direct negative effect of maturation on parr growth and recruitment to smolt. Thus, parr maturation is an important consideration for the enhancement and (or) restoration of Atlantic salmon populations via stream stocking programs.

Paralepis coregonoides borealis (Osteichthyes: Paralepididae) from Davis Strait and Labrador Sea

1971 ◽  
Vol 28 (8) ◽  
pp. 1199-1203
Author(s):  
W. H. Lear ◽  
A. W. May
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
West Coast ◽  
Labrador Sea ◽  
The West ◽  
Atlantic Salmon Salmo Salar ◽  
Davis Strait

Twenty Paralepis specimens were taken from the stomachs of 10 Atlantic salmon (Salmo salar L.) caught by drift net at seven fishing stations in the Davis Strait and Labrador Sea. Eleven of the 20 specimens were identified as Paralepis coregonoides borealis Reinhardt on the basis of vertebral counts, and the remainder are tentatively assigned to this species. These are the first records of adult specimens from the Davis Strait, though a few have been recorded from the west coast of Greenland.

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