Climatic and Oceanic Variations Affecting Yield of Icelandic Stocks of Atlantic Salmon (Salmo salar)

1984 ◽  
Vol 41 (6) ◽  
pp. 917-935 ◽  
Author(s):  
Dennis L. Scarnecchia
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Water ◽  
North Coast ◽  
Growth And Survival ◽  
Atlantic Salmon Salmo Salar ◽  
The North ◽  
Air Temperatures ◽  
Western Group ◽  
June July

Regression analysis was used to investigate the effects of variations in climate, weather, and ocean conditions on yields of Atlantic salmon (Salmo salar) to anglers from 15 Icelandic rivers. Catches of grilse from the northern and northeastern group of rivers fluctuated together, as did catches from the southwestern and western group of rivers, but seldom did catches from the two groups of rivers fluctuate together. The dividing point for grouping rivers with similarly fluctuating catches was the northwest peninsula, which separated warm Atlantic water from colder north Icelandic waters of the Iceland Sea. Changes in atmospheric circulation (mid-1950's to mid-1960's) resulted in marked changes in hydrography off north Iceland from 1965 to 1970, which coincided with declines in primary production and standing crops of zooplankton, in reduced abundance and altered distribution of pelagic forage fishes, and in declines in salmon yields from north coast rivers. Few grilse were also caught from most rivers in 1980 after low sea and air temperatures in spring of 1979. Highly significant relationships were found between mean June–July sea temperatures at Hraun on the north coast and yield of grilse the following year from the northern rivers Vatnsdalsá, Vídidalsá, Hrútafjardará, and Midfjardará and its three tributaries. Sea temperatures in April–May and May–June were also closely correlated (P < 0.01 and P < 0.05) with grilse catches from these rivers. Correlations were similar but less close for two-sea-winter salmon. Fewer statistically significant relations were found between sea temperatures and yields for south coast rivers; sea temperatures were higher there and varied less between years. Inasmuch as low sea temperatures and low river temperatures often occur in the same years, salmon yields may be regulated by several adverse climatic and hydrographic factors acting in combination, resulting in delayed smoltification and reduced growth and survival at sea.

The marine phase of the Atlantic salmon (Salmo salar) life cycle, with comparisons to Pacific salmon

1998 ◽  
Vol 55 (S1) ◽  
pp. 104-118 ◽  
Author(s):  
L P Hansen ◽  
T P Quinn
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Life Histories ◽  
North Atlantic Ocean ◽  
Pacific Salmon ◽  
Mortality Factor ◽  
Growth And Survival ◽  
Atlantic Salmon Salmo Salar ◽  
The North ◽  
Wide Range

Atlantic salmon (Salmo salar) are distributed over large areas in the north Atlantic Ocean. They usually move very quickly from freshwater to oceanic areas, whereas there is considerable variation among Pacific salmon in early marine movements. In some areas, Atlantic salmon of exploitable size are sufficiently abundant that commercial high seas fisheries have developed. Such areas are off west Greenland, where North American and European fish are harvested, and in the Norwegian Sea, north of the Faroe Islands, where mainly European fish are exploited. Atlantic salmon feed on a wide range of large crustaceans, pelagic fish, and squid in the marine environment, supporting the hypothesis that Atlantic salmon are opportunistic feeders. In the ocean the salmon grow relatively quickly and the sea age when they become sexually mature depends on both genetics and on growing conditions. Natural marine mortality of salmon is highest during the first few months at sea and the major mortality factor is probably predation. However, marine mortality of Atlantic salmon has increased in recent years, apparently correlated with a decline in sea surface temperatures. Similar relationships between environmental conditions and the growth and survival of Pacific salmon have been reported. Atlantic salmon life histories most closely mimic stream-type chinook salmon or steelhead trout among the Pacific species. Finally, Atlantic and Pacific salmon return to their home rivers with high precision and possible mechanisms controlling the oceanic homing migration are presented and discussed.

Stocks of Atlantic Salmon (Salmo salar) in Britain and Ireland: Discreteness, and Current Management

1981 ◽  
Vol 38 (12) ◽  
pp. 1576-1590 ◽  
Author(s):  
J. E. Thorpe ◽  
K. A. Mitchell
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Gene Frequencies ◽  
Commercial Catch ◽  
Environmental Pressures ◽  
Atlantic Salmon Salmo Salar ◽  
The North ◽  
Western Group ◽  
Transferrin Gene ◽  
Separate Identity

The null hypothesis that all Atlantic salmon (Salmo salar) in the North Atlantic belong to a common stock is shown to be untenable, on the grounds of differences between North American and European populations in transferrin gene frequencies, chromosome numbers, and numbers of circuli on scales. The further hierarchical breakdown of the European fraction into western, northern, and Baltic components is revealed through tagging data, which also shows distinctions within the western group, segregating into Icelandic, French, and British/Irish subpopulations. Within the latter, two groups are definable on the basis of differences in transferrin (Tf2) gene frequencies, the boreal and celtic races. Within the Celtic race, the populations of the neighboring rivers Bandon and Blackwater (Cork) have been shown to be distinct reproductively isolated stocks, on the basis of differences in gene frequencies in two enzymes (IDH-A, and AAT-A). Circumstantial evidence for the separate identity of 74 river stocks in Britain and Ireland, on the basis of differences in age structure at the smolt and adult stage, and size at return to the rivers, is supported by evidence from tagging experiments of a high incidence of homing to the native river, experimental evidence of the heritability of growth and developmental traits, and evidence from scale data of differences in specific growth rate of individual river populations during their 1st year at sea. Environmental pressures selecting for differences between river stocks are suggested by the significant positive correlation between river length and fish size at maturity. Differences in patterns of change in the commercial catch over the period 1952–76 indicate regional groups of river stocks within Scotland. The existence of such discrete stocks of Atlantic salmon implies the need for management on a stock-by-stock basis. Current national and international regulations do not achieve this goal.Key words: Atlantic salmon, transferrin gene frequencies, river stocks, management

The effect of porcine somatotropin on growth, and survival in seawater of Atlantic salmon (Salmo salar) parr

1976 ◽  
Vol 54 (4) ◽  
pp. 531-535 ◽  
Author(s):  
M. P. Komourdjian ◽  
R. L. Saunders ◽  
J. C. Fenwick
Keyword(s):  
Growth Hormone ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Growth Hormone Treatment ◽  
Hormone Treatment ◽  
Control Fish ◽  
Growth And Survival ◽  
Atlantic Salmon Salmo Salar ◽  
Porcine Somatotropin

The effects of porcine growth hormone on growth and salinity tolerance were studied in Atlantic salmon (Salmo salar) parr. Fish were held in freshwater at 11.5 °C during June and July under a photoperiod with light to dark periods opposite to the prevailing natural conditions. Fish treated with 1.0 μg/g body weight of growth hormone preparation on alternate days were significantly longer (P <.05), after 4 weeks, than placebo-injected controls. All hormone-injected fish survived transfer to seawater, 30‰ salinity. But under the same conditions, placebo-injected control fish showed a high mortality rate. Growth-hormone treatment caused a darkening of fin margins and a yellowing of the operculae and fin surfaces. The silvering which normally accompanies smoltification was not observed. The role of growth hormone in eliciting these actions and its possible role in the parr–smolt transformation are discussed.

Long-term changes in migration timing of adult Atlantic salmon (Salmo salar) at the southern edge of the species distribution

2004 ◽  
Vol 61 (12) ◽  
pp. 2392-2400 ◽  
Author(s):  
Francis Juanes ◽  
Stephen Gephard ◽  
Kenneth F Beland
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Global Climate ◽  
Life History Trait ◽  
Connecticut River ◽  
Migration Timing ◽  
Atlantic Salmon Salmo Salar ◽  
The North ◽  
Long Term Changes

The Connecticut River historically represented the southernmost extent of the North American range of Atlantic salmon (Salmo salar), but the native population was extirpated 200 years ago by dam construction. An extensive restoration effort has relied upon stock transfers from more northerly rivers, especially the Penobscot River (Maine). Recent work has shown differences in age structure between donor and derivative populations. Here we focus on a related life-history trait, the timing of the adult migration. We examined 23 years of migration timing data collected at two capture locations in the Connecticut River drainage. We found that both dates of first capture and median capture dates have shifted significantly earlier by about 0.5 days·year–1. To conclude whether this is a consequence of local adaptation or a coast-wide effect, we also quantified changes in migration timing of more northerly stocks (in Maine and Canada). We found that the changes in migration timing were not unique to the Connecticut River stock and instead observed coherent patterns in the shift towards earlier peak migration dates across systems. These consistent shifts are correlated with long-term changes in temperature and flow and may represent a response to global climate change.

scholarly journals Evolution of the Piscine orthoreovirus Genome Linked to Emergence of Heart and Skeletal Muscle Inflammation in Farmed Atlantic Salmon (Salmo salar)

Viruses ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 465 ◽  
Author(s):  
Kannimuthu Dhamotharan ◽  
Torstein Tengs ◽  
Øystein Wessel ◽  
Stine Braaen ◽  
Ingvild B. Nyman ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Muscle Inflammation ◽  
Atlantic Salmon Salmo Salar ◽  
The North ◽  
Farmed Atlantic Salmon ◽  
Associated Pair ◽  
Viral Sequences ◽  
Selection Of

Heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar) was first diagnosed in Norway in 1999. The disease is caused by Piscine orthoreovirus-1 (PRV-1). The virus is prevalent in farmed Atlantic salmon, but not always associated with disease. Phylogeny and sequence analyses of 31 PRV-1 genomes collected over a 30-year period from fish with or without HSMI, grouped the viral sequences into two main monophylogenetic clusters, one associated with HSMI and the other with low virulent PRV-1 isolates. A PRV-1 strain from Norway sampled in 1988, a decade before the emergence of HSMI, grouped with the low virulent HSMI cluster. The two distinct monophylogenetic clusters were particularly evident for segments S1 and M2. Only a limited number of amino acids were unique to the association with HSMI, and they all located to S1 and M2 encoded proteins. The observed co-evolution of the S1-M2 pair coincided in time with the emergence of HSMI in Norway, and may have evolved through accumulation of mutations and/or segment reassortment. Sequences of S1-M2 suggest selection of the HSMI associated pair, and that this segment pair has remained almost unchanged in Norwegian salmon aquaculture since 1997. PRV-1 strains from the North American Pacific Coast and Faroe Islands have not undergone this evolution, and are more closely related to the PRV-1 precursor strains not associated with clinical HSMI.

scholarly journals Inferring marine distribution of Canadian and Irish Atlantic salmon (Salmo salar L.) in the North Atlantic from tissue concentrations of bio-accumulated caesium 137

2007 ◽  
Vol 64 (2) ◽  
pp. 394-404 ◽  
Author(s):  
Aaron D. Spares ◽  
Jeffery M. Reader ◽  
Michael J. W. Stokesbury ◽  
Tom McDermott ◽  
Lubomir Zikovsky ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
North Atlantic ◽  
Tissue Concentration ◽  
Eastern Canada ◽  
Tissue Concentrations ◽  
Atlantic Salmon Salmo Salar ◽  
The North ◽  
The North Atlantic ◽  
High Concentrations

AbstractSpares, A.D., Reader, J.M., Stokesbury, M.J.W., McDermott, T., Zikovsky, L., Avery, T.S., and Dadswell, M.J. 2007. Inferring marine distribution of Canadian and Irish Atlantic salmon (Salmo salar L.) in the North Atlantic from tissue concentrations of bio-accumulated caesium 137. – ICES Journal of Marine Science, 64: 394–404. Atlantic salmon returning from marine migrations to eastern Canada and western Ireland during 2002 and 2003 were analysed for tissue concentrations of bio-accumulated caesium 137 (137Cs). Salmon from Canadian and Irish waters demonstrated concentrations (0.20 ± 0.14 Bq kg−1 and 0.19 ± 0.09 Bq kg−1, mean ± s.d., respectively) suggesting similar oceanic feeding distributions during migration. Canadian aquaculture escapees had a similar mean tissue concentration (0.28 ± 0.22 Bq kg−1), suggesting migration with wild salmon. However, significantly higher concentrations in 1-sea-winter (1SW) escapees (0.43 ± 0.25 Bq kg−1) may alternatively suggest feeding within local estuaries. High concentrations in some Canadian 1SW salmon indicated trans-Atlantic migration. Low concentrations of Canadian multi-sea-winter (MSW) salmon suggested a feeding distribution in the Labrador and Irminger Seas before homeward migration, because those regions have the lowest surface water 137Cs levels. Estimates of wild Canadian and Irish salmon feeding east of the Faroes (∼8°W) were 14.2% and 10.0% (1SW, 24.7% and 11.5%; MSW, 2.9% and 0.0%), respectively. We propose that most anadromous North Atlantic salmon utilize the North Atlantic Gyre for marine migration and should be classified as a single trans-Atlantic straddling stock.

Growth and survival of Atlantic salmon (Salmo salar) in Llyn Dwythwch, North Wales

1978 ◽  
Vol 8 (5) ◽  
pp. 423-431 ◽  
Author(s):  
R. B. PEDLEY ◽  
J. W. JONES
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Growth And Survival ◽  
Atlantic Salmon Salmo Salar ◽  
North Wales

Effect of astaxanthin and vitamin A on growth and survival during first feeding of Atlantic salmon, Salmo salar L.

1994 ◽  
Vol 25 (9) ◽  
pp. 903-914 ◽  
Author(s):  
R. Christiansen ◽  
Ø. Lie ◽  
O.J. Torrissen
Keyword(s):  
Vitamin A ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Growth And Survival ◽  
Atlantic Salmon Salmo Salar ◽  
First Feeding
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