Atlantic Salmon (Salmo salar) Stocks and Management Implications in the Canadian Atlantic Provinces and New England, USA

1981 ◽  
Vol 38 (12) ◽  
pp. 1612-1625 ◽  
Author(s):  
Richard L. Saunders
Keyword(s):  
Atlantic Salmon ◽  
New England ◽  
Salmo Salar ◽  
Environmental Influence ◽  
Function Analysis ◽  
Significant Degree ◽  
Growth Patterns ◽  
Point Of View ◽  
Atlantic Salmon Salmo Salar ◽  
Mixed Stock

This paper discusses the diversity of Atlantic salmon (Salmo salar) expressed as anatomical, physiological, and behavioral differences among stocks in the Atlantic Provinces of Canada and New England, USA. Evidence is reviewed for environmental and genetic influence on a number of stock-specific traits. Unique qualities of particular stocks are described. The loss of salmon from much of its former range is documented and discussed in relation to stock characteristics important in rehabilitation efforts. The mixed stock fisheries in Greenland and Newfoundland are considered from the point of view of interception. It is concluded that identification and management of specific stocks in the Greenland fishery are impracticable at present but that identification of North American components, using discriminant function analysis of scale growth patterns and smolt tagging, should be continued. In Newfoundland knowledge gained from tagging studies allows a significant degree of management of stocks from mainland Canada together with those from Newfoundland and Labrador. Since it is impracticable now to manage the fisheries off Greenland and Newfoundland and off the major Canadian Maritimes salmon-producing rivers—the Miramichi, Restigouche, and Saint John—in strict recognition of stocks, it is suggested that it may be possible to characterize an assemblage of like stocks from given areas and to identify and manage for these in large mixed-stock fisheries. Possible impacts of hatchery plantings are discussed in relation to prospects of success and effects on native stocks. It is concluded that we have the biological basis for evaluating likelihood of success and degree of danger to native stocks from extensive plantings of hatchery-reared juvenile salmon and that such evaluation should be conducted when embarking on projects involving use of hatchery-reared fish as part of a major salmon enhancement program in Atlantic Canada.Key words: genetics, environmental influence, rehabilitation, enhancement, interception, hatcheries, aquaculture

Growth and Genetic Variation of Atlantic Salmon (Salmo salar) from Different Sections of the River Alta, North Norway

1986 ◽  
Vol 43 (10) ◽  
pp. 1828-1835 ◽  
Author(s):  
Tor G. Heggberget ◽  
Roar A. Lund ◽  
Nils Ryman ◽  
Gunnar Ståhl
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Growth Patterns ◽  
Lower Growth ◽  
Local Populations ◽  
Atlantic Salmon Salmo Salar ◽  
Lower Growth Rate ◽  
Growth Differences ◽  
North Norway ◽  
Smolt Age

Growth of young Atlantic salmon (Salmo salar) from three different sections of the River Alta was correlated with estimated growth differences among adult salmon caught in corresponding sections of the river. Young salmon grew most quickly each of the three years investigated in the upper section of the river; further downriver, presmolts had a significantly lower growth rate. Growth calculations based on scale samples from adults indicated corresponding river growth patterns from the three sections. Salmon caught in the upper section of the river had significantly lower smolt age (mean 3.92 yr) and better presmolt growth than salmon caught further downriver (mean smolt age in the middle and lower sections was 4.35 and 4.19 yr, respectively). Correlations between growth differences in young and adult salmon suggest that presmolts that have lived their first years in the upper section of the river apparently return there after having been at sea. Genetic analyses of presmolts indicate that local populations exist. Allele frequency differences at three electrophoretically detectable protein loci give independent support for the existence of genetically differentiated local populations within the River Alta.

scholarly journals Provision of catch advice taking account of non-stationarity in productivity of Atlantic salmon (Salmo salar L.) in the Northwest Atlantic

2005 ◽  
Vol 62 (1) ◽  
pp. 131-143 ◽  
Author(s):  
G. Chaput ◽  
C.M. Legault ◽  
D.G. Reddin ◽  
F. Caron ◽  
P.G. Amiro
Keyword(s):  
Population Dynamics ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Model Prediction ◽  
Northwest Atlantic ◽  
Atlantic Salmon Salmo Salar ◽  
Parsimonious Models ◽  
Rate Of Decline ◽  
Management Advice ◽  
Mixed Stock

Abstract The paper presents the data, the models, and the approach for the provision of management advice for a high seas mixed stock fishery on Atlantic salmon (Salmo salar L.). The approach incorporates observation errors, model uncertainty, and considers a possible shift in the productivity of Atlantic salmon. The risk analysis framework further incorporates uncertainty in the fishery harvest characteristics and presents the catch advice as probabilities of meeting or exceeding the conservation objectives relative to catch options. There is very strong evidence from the analyses that there has been a phase shift in productivity of Atlantic salmon of North American origin in the Northwest Atlantic. The change in productivity likely resulted from a change in marine survival which occurred in the early 1990s and has persisted to date. When the uncertainties in the input data are considered, the most parsimonious models suggest that there has been a shift in absolute abundance independent of variations in the spawner index contributing to the recruitment. There continues to be a large amount of uncertainty in the measures of abundance and population dynamics of Atlantic salmon. Uncertainty in the understanding of population dynamics does not necessarily equate to uncertainty in management advice. If model results suggest that spawning objectives are unattainable even when harvest rates are zero, then any harvest level will either accelerate the rate of decline if the model prediction is correct or diminish the probability of recovery if the model prediction is wrong.

scholarly journals Migration of Postsmolt Atlantic Salmon, Salmo salar, Off Northeastern Newfoundland, As Inferred by Tag Recoveries in a Seabird Colony

1988 ◽  
Vol 45 (3) ◽  
pp. 568-571 ◽  
Author(s):  
W. A. Montevecchi ◽  
D. K. Cairns ◽  
V. L. Birt
Keyword(s):  
Nova Scotia ◽  
Atlantic Salmon ◽  
New England ◽  
Salmo Salar ◽  
Atlantic Coast ◽  
Food Samples ◽  
Seabird Species ◽  
Atlantic Salmon Salmo Salar ◽  
Penobscot River ◽  
Migratory Pattern

Northern gannets, Sula bassanus, and possibly other seabird species nesting on Funk Island off northeastern Newfoundland preyed on postsmolt Atlantic salmon, Salmo salar. Salmon comprised less than 1% of 2928 regurgitated food samples collected from gannets at the colony. Ten smolt tags were recovered in and near the gannetry during August or September in 1984 through 1986. The tags were from smolts released 3–4 mo earlier in the Penobscot River (Maine) (n = 7) and one each from the Saint John River (New Brunswick) and the Lower Clyde and LaHave rivers (Nova Scotia). These recoveries provide evidence that postsmolt Atlantic salmon from rivers in New England, the Bay of Fundy, and the Atlantic coast of Nova Scotia migrate off eastern Newfoundland This migratory pattern contrasts with that of postsmolts from the Gulf of St. Lawrence, which tend to move northwards along Newfoundland's west coast and through the Strait of Belle Isle.

Hotelling's T2 to Identify the Origin of Atlantic Salmon (Salmo salar) in a Mixed-Stock Fishery

1985 ◽  
Vol 42 (2) ◽  
pp. 250-255 ◽  
Author(s):  
D. G. Reddin ◽  
R. K. Misra
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Misclassification Rate ◽  
Commercial Fishery ◽  
Commercial Sample ◽  
New Approach ◽  
Atlantic Salmon Salmo Salar ◽  
Leave One Out ◽  
Mixed Stock ◽  
River Size

We used a new approach based on measurements of four scale characters, for identifying Atlantic salmon (Salmo salar) caught in the commercial fishery at St. Ann's Harbour, Nova Scotia, and that were returning to North River. Utilizing Hotelling's T2, we compared the vector of observations of each member of the commercial sample (size = 29) with the vector of means of the sample from the angling fishery on North River (size = 48). Misclassification rate was estimated by the "leave-one-out" technique. The variables chosen for analysis were the measurements of the longest oral radii between each of the first three river and first sea annuli. The analysis indicated that 79–88% of the individuals in the commercial sample could have been migrating to North River. This technique is proposed for cases in which the requirement to have samples from all contributing stocks for discriminant analysis is not possible.

Spatiotemporal dynamics of the Atlantic salmon (Salmo salar) Greenland fishery inferred from mixed-stock analysis

2009 ◽  
Vol 66 (12) ◽  
pp. 2040-2051 ◽  
Author(s):  
Marika Gauthier-Ouellet ◽  
Mélanie Dionne ◽  
François Caron ◽  
Tim L. King ◽  
Louis Bernatchez
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Time Course ◽  
Fish Stocks ◽  
Atlantic Salmon Salmo Salar ◽  
The North ◽  
Different Origins ◽  
Mixed Stock ◽  
Mortality Estimates

Mixed-stock fisheries refer to the exploitation of admixed fish stocks coming from different origins. We identified the North American origin of 2835 Atlantic salmon ( Salmo salar ) in the Greenland mixed-stock fishery during 11 years (1995–2006) at three localities using 13 microsatellites. The study included 52 baseline populations representing nine genetically distinct regional groups. The contribution of each group ranged from <1% (Maine) to 40% (Southern Québec). Decreasing temporal contributions were observed for Southern Québec (–22.0%) and New Brunswick (–17.4%), whereas an increasing contribution for Labrador (+14.9%) was observed during the time course of the study. The estimated regional contribution to the Greenland fishery was significantly correlated to the number of multi-sea-winter salmon regionally produced in 2002 (r = 0.79) and 2004 (r = 0.92). No difference in contribution was found between the three Greenland sampling localities. Ungava and Southern Québec regions showed the highest mortality estimates caused by the fishery, ranging from 12.10% to 18.08%, for both years tested. No regional group was overrepresented in landings compared with their respective productivity. Yet, management precautions should still be taken as the fishery strongly selects large females, which could have evolutionary impacts on populations over the long term.

Distinguishing between resident and migrating Atlantic salmon (Salmo salar) stocks by genetic stock composition analysis

1995 ◽  
Vol 52 (4) ◽  
pp. 665-674 ◽  
Author(s):  
Marja-Liisa Koljonen
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Composition Analysis ◽  
The Baltic Sea ◽  
Genetic Stock ◽  
Atlantic Salmon Salmo Salar ◽  
Genetic Stock Identification ◽  
The Baltic ◽  
Catch Composition ◽  
Mixed Stock

The possibility of using the genetic stock identification (GSI) method to distinguish between individual Atlantic salmon (Salmo salar) stocks and stock groups in Finnish catches was studied. In the Baltic Sea, the Atlantic salmon is a target of a mixed-stock fishery, and information about stock composition would be valuable for the management of the species. The salmon catches on the Finnish west coast consist of two seasonally variable components: a group of northern stocks migrating through the area to the Baltic main basin and the resident Neva salmon. The migratory component includes two endangered wild stocks (Tornionjoki and Simojoki). The allele frequency differences at four polymorphic loci among the stocks allowed reliable catch composition estimates to be made of the migratory and resident components; one stock (Oulujoki) from the northern group could also be identified with reasonable accuracy. Northern migrating stocks accounted for over half the catches at the time of this study. The estimate of natural (nonhatchery) stocks was very low (3% in total).

Comparing naturally occurring stable isotopes of nitrogen, carbon, and strontium as markers for the rearing locations of Atlantic salmon (Salmo salar)

2005 ◽  
Vol 62 (1) ◽  
pp. 48-57 ◽  
Author(s):  
Brian P Kennedy ◽  
C Page Chamberlain ◽  
Joel D Blum ◽  
Keith H Nislow ◽  
Carol L Folt
Keyword(s):  
Stable Isotopes ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Function Analysis ◽  
Connecticut River ◽  
Isotopic Signatures ◽  
Atlantic Salmon Salmo Salar ◽  
Analysis Group ◽  
C Isotopes ◽  
Naturally Occurring

We compared the success of using naturally occurring stable isotopes of N, C, and Sr as markers for the rearing locations of juvenile salmon. We analyzed the isotopic signatures (δ15N and δ13C in muscle and scales and 87Sr/86Sr in otoliths) of >200 juvenile Atlantic salmon (Salmo salar) from 12 tributaries of the Connecticut River, USA. Young salmon had distinct N and C signatures 5 weeks after stocking. Signatures were stable over the summer although δ13C varied more than δ15N or 87Sr/86Sr. Scale and muscle signatures were highly correlated, demonstrating the feasibility of nonlethal sampling using fish scales. Some C (but not N) signature from the hatchery was retained in scales of 3-month-old fish, implicating scale annuli as a repository for past C signatures. The δ15N values successfully differentiated fish from tributaries with differences in land use (e.g., agricultural versus forested; ≈ 33% of sites); the δ13C values differentiated fish from 45% of sites. Based upon a discriminant-function analysis, group membership of individuals was correctly predicted in 44.3% (74 of 167) of cases for which both N and C were analyzed. In combination, N and C isotopes differentiated 73% of study sites, which was close to the success of Sr isotopes in the same system (83%).

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.

Variation in freshwater growth and development among five New England Atlantic salmon (Salmo salar) populations reared in a common environment

2004 ◽  
Vol 61 (12) ◽  
pp. 2314-2328 ◽  
Author(s):  
Mariska Obedzinski ◽  
Benjamin H Letcher
Keyword(s):  
Atlantic Salmon ◽  
New England ◽  
Salmo Salar ◽  
Growth And Development ◽  
Size Variation ◽  
Phenotypic Trait ◽  
Frequency Distributions ◽  
Atlantic Salmon Salmo Salar ◽  
Intensively Managed ◽  
Smolt Age

We examined phenotypic variation in growth and development from the eyed-egg stage to the age-1+ smolt stage among five New England populations of Atlantic salmon (Salmo salar: East Machias, Narraguagus, Sheepscot, Penobscot, Connecticut) reared in a common laboratory environment. Study populations originated from rivers varying in size, latitude, and level of hatchery supplementation and included one reintroduced population (Connecticut was a recipient of Penobscot origin stock). Phenotypic trait differences were found among populations, and the degree of stock variation depended on ontogeny. Eggs were smaller and hatched sooner in the Penobscot (a northern, intensively managed population), but no stock differences were detected in size or growth efficiency from the onset of exogenous feeding to age 0+ summer. Differences again emerged in age 0+ autumn, with the degree of bimodality in length– frequency distributions differing among stocks; the Connecticut had the highest proportion of upper-mode fish and, ultimately, age-1+ smolts. Although genetic effects could not be entirely separated from maternal effects for egg size variation, it is likely that differences in hatch timing and smolt age had a genetic basis. Early emphasis on age-1+ hatchery-reared smolts in the Connecticut may have led to divergence in smolt age between the Penobscot and Connecticut populations in less than eight generations.

scholarly journals Managing Atlantic salmon (Salmo salar L.) in the mixed stock environment: challenges and considerations

2004 ◽  
Vol 61 (8) ◽  
pp. 1344-1358 ◽  
Author(s):  
W.W. Crozier ◽  
P-J. Schön ◽  
G. Chaput ◽  
E.C.E. Potter ◽  
N.Ó Maoiléidigh ◽  
...  
Keyword(s):  
Population Structure ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar ◽  
Mixed Stock ◽  
Made In

Abstract Atlantic salmon, as a result of their population structure and behaviour, are potentially subject to a complex array of fisheries, ranging from those within rivers harvesting single stocks, to distant-water mixed stock fisheries that harvest fish from different countries, stock complexes, and continents. In addition, estuarine and in-river fisheries may catch fish from more than one stock or stock component, where these are present. One of the main challenges in managing salmon across this range of fisheries is to account for the differing status of stocks with respect to safe biological limits, noting that stocks of differing productivity may require different harvest strategies. Also, the existence of sequential harvest in different fisheries provides unique challenges, because decisions in an individual fishery cannot be made in isolation of the impacts of other fisheries on those stocks. We illustrate the uncertainties and complexities involved in managing mixed stocks of salmon, whether in home-waters or in distant-water fisheries, and examples are given to illustrate how science and management are, or should be, developing to face these challenges.

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