Instant myth: the case of the west Greenland salmon

Polar Record ◽  
1975 ◽  
Vol 17 (109) ◽  
pp. 355-358 ◽  
Author(s):  
M. J. Dunbar
Keyword(s):  
Atlantic Salmon ◽  
The West ◽  
West Greenland ◽  
The Public ◽  
Davis Strait ◽  
Pelagic Fishery

It has been said that scientific truths begin as heresies and end as myths, enjoying a period of orthodox acceptance in between. It must be rare, if this is so, for a myth to be imposed upon the public as a “truth”, to be accepted immediately as such, and then to suffer excommunication as heresy. Such a case is at hand in the matter of the sea-life area of the Atlantic Salmon in Davis Strait and of the start of a new pelagic fishery.

scholarly journals Genetic mixed-stock analysis disentangles spatial and temporal variation in composition of the West Greenland Atlantic Salmon fishery

2016 ◽  
Vol 73 (9) ◽  
pp. 2311-2321 ◽  
Author(s):  
Ian R. Bradbury ◽  
Lorraine C. Hamilton ◽  
Timothy F. Sheehan ◽  
Gerald Chaput ◽  
Martha J. Robertson ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
North American ◽  
Temporal Stability ◽  
Spatial And Temporal Variation ◽  
Published Data ◽  
The West ◽  
West Greenland ◽  
Archived Samples ◽  
Mixed Stock ◽  
Salmon Fishery

Abstract The West Greenland Atlantic Salmon (Salmo salar) fishery represents the largest remaining mixed-stock fishery for Atlantic Salmon in the Northwest Atlantic and targets multi-sea-winter (MSW) salmon from throughout North America and Europe. We evaluated stock composition of salmon harvested in the waters off West Greenland (n = 5684 individuals) using genetic mixture analysis and individual assignment to inform conservation of North American populations, many of which are failing to meet management targets. Regional contributions to this fishery were estimated using 2169 individuals sampled throughout the fishery between 2011 and 2014. Of these, 22% were identified as European in origin. Major North American contributions were detected from Labrador (∼20%), the Southern Gulf/Cape Breton (29%), and the Gaspe Peninsula (29%). Minor contributions (∼5%) were detected from Newfoundland, Ungava, and Quebec regions. Region-specific catches were extrapolated using estimates of composition and fishery catch logs and harvests ranged from 300 to 600 and 2000 to 3000 individuals for minor and major constituents, respectively. To evaluate the temporal stability of the observed fishery composition, we extended the temporal coverage through the inclusion of previously published data (1995–2006, n = 3095) and data from archived scales (1968–1998, n = 420). Examination of the complete time-series (47 years) suggests relative stability in stock proportions since the late 1980s. Genetic estimates of stock composition were significantly associated with model-based estimates of returning MSW salmon (individual years r = 0.69, and overall mean r = 0.96). This work demonstrates that the analysis of both contemporary and archived samples in a mixed-stock context can disentangle levels of regional exploitation and directly inform assessment and conservation of Atlantic Salmon in the West Greenland interceptory Atlantic Salmon fishery.

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.

Sediment supply on the West Greenland passive margin: redirection of a large pre-glacial drainage system

2020 ◽  
Vol 177 (6) ◽  
pp. 1149-1160
Author(s):  
Scott Jess ◽  
Alexander L. Peace ◽  
Christian Schiffer
Keyword(s):  
Drainage System ◽  
Sediment Supply ◽  
Passive Margin ◽  
Fluvial System ◽  
The West ◽  
Drainage Systems ◽  
West Greenland ◽  
Igneous Province ◽  
Davis Strait ◽  
Supplementary Material

The Mesozoic–Cenozoic separation of Greenland and North America produced the small oceanic basins of the Labrador Sea and Baffin Bay, connected via a complex transform system through the Davis Strait. During rifting and partial breakup sedimentary basins formed that record the changing regional sediment supply. The onshore and offshore stratigraphy of Central West Greenland outlines the presence of a major fluvial system that existed during the Cretaceous and was later redirected in the Early Cenozoic by the formation of the West Greenland Igneous Province. Hydrological analysis of Greenland's isostatically balanced basement topography outlines two major drainage systems that likely flowed across Greenland prior to the onset of glaciation and emptied into the Sisimiut Basin within the Davis Strait, offshore West Greenland. The course of the northern drainage system suggests that it initially flowed NW into the Cretaceous/Palaeocene Nuussuaq Basin, before being redirected SW around the West Greenland Igneous Province in the Mid-Palaeocene. Moreover, characteristics of these two drainage systems suggest they acted as a single larger fluvial system, prior to the onset of glaciation, that was likely the primary source of sediment across Central West Greenland throughout the Cretaceous and Palaeogene. This scenario provides a greater understanding of the West Greenland margin's late Cenozoic evolution, which differs from previous interpretations that hypothesize a period of considerable post-rift tectonism and uplift. This work highlights the importance of large pre-glacial drainage systems across North Atlantic passive margins and their relevance when studying post-rift stratigraphy in rifted margin settings.Supplementary material: Isostatic modelling, hydrological analysis and chi mapping is available at: https://doi.org/10.6084/m9.figshare.c.5050146

scholarly journals Early Tertiary, low-potassium tholeiites from exploration wells on the West Greenland shelf

1987 ◽  
Vol 136 ◽  
pp. 1-25
Author(s):  
N Hald ◽  
J.G Larsen
Keyword(s):  
Baffin Island ◽  
Quaternary Sediments ◽  
The South ◽  
The West ◽  
Baffin Bay ◽  
West Greenland ◽  
Early Tertiary ◽  
Davis Strait ◽  
Low Potassium

Data on the Tertiary basalts in the Davis Strait region are reported from two exploration wells drilled by Arco and Mobil on the West Greenland shelf. Hellefisk 1 (67°53 'N, 56°44'W), situated only 60 km east of the mid-line in Davis Strait, penetrated the upper 690 m of a subaeriallava sequence continuous with the onshore volcanics of Disko and situated beneath 2.3 km of Paleocene to Quaternary sediments. The lavas are feldspar microporphyritic tholeiites and mostly unmetamorphosed despite the presence of laumontite and prehnite in the vesicular top zones. Nukik 2 (65°38'N, 54°46'W) penetrated 150 m of hyaloclastites and tholeiitic olivine dolerite sheets, presumably sills, some 200 km further to the south. These vo1canics are also deeply buried and are of unknown extension. The drilled rocks, except for the much altered hyaloclastites in the Nukik 2 well, have low contents of Ti02 (0.99-2.03%), K2O (0.09-0.18%) and P2O5 (0.08-0.21%), La/Sm ratios less than one and 87Sr/86Sr ratios of 0.7032 to 0.7044. Chemically they are related to the MORB-like picrites of Baffin Island rather than the less depleted tholeiites of West Greenland. In both areas the MORB affinity may be related to eruptions through a strongly attenuated lithosphere associated with the opening of Baffin Bay and Davis Strait.

scholarly journals Probabilistic-based genetic assignment model: assignments to subcontinent of origin of the West Greenland Atlantic salmon harvest

2009 ◽  
Vol 67 (3) ◽  
pp. 537-550 ◽  
Author(s):  
Timothy F. Sheehan ◽  
Christopher M. Legault ◽  
Timothy L. King ◽  
Adrian P. Spidle
Keyword(s):  
Atlantic Salmon ◽  
North American ◽  
Dna Analysis ◽  
Biological Data ◽  
The West ◽  
Genetic Assignment ◽  
West Greenland ◽  
Assignment Model ◽  
Misclassification Rates ◽  
Mixed Stock

Abstract Sheehan, T. F., Legault, C. M., King, T. L., and Spidle, A. P. 2010. Probabilistic-based genetic assignment model: assignments to subcontinent of origin of the West Greenland Atlantic salmon harvest. – ICES Journal of Marine Science, 67: 537–550. A multistock Atlantic salmon (Salmo salar) fishery operates off the coast of West Greenland and harvests fish of North American and European origin. Annual landings peaked in 1971 at 2700 t, but declined to 22 t in 2003. Biological data are collected to characterize the catch and its stock composition. Multilocus genotypes, generated via microsatellite DNA analysis, are used to derive statistics on continent of origin and less accurate finer-scale assignments. We developed a probabilistic-based genetic assignment (PGA) model to estimate the contribution of salmon from individual North American rivers in the 2000–2003 West Greenland catch. Uncertainty associated with finer-scale assignments is addressed by incorporating estimated misclassification rates and by reporting results as distributions generated via Monte Carlo resampling. US-origin fish represented ∼1% (by number) of the salmon harvested at West Greenland during the years 2000–2003. The resulting loss of spawners to this stock complex was approximately half the estimated adult returns in 2001, but was below 4% in the other 3 years. This is the first attempt to partition the US component of the West Greenland mixed-stock fishery to its finer parts. The approach can be used to identify the effects of fishing on individual stocks within any multistock complex where genetic samples of known origin are available.

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.

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.

Petroleum geological activities in West Greenland in 2000

2001 ◽  
pp. 24-33 ◽  
Author(s):  
Flemming G. Christiansen ◽  
Jørgen A. Bojesen-Koefoed ◽  
James A. Chalmers ◽  
Finn Dalhoff ◽  
Anders Mathiesen ◽  
...  
Keyword(s):  
Press Release ◽  
Geological Survey ◽  
Petroleum Geology ◽  
Original Series ◽  
West Greenland ◽  
The Public ◽  
Technical Work ◽  
The Press ◽  
Seismic Acquisition

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Christiansen, F. G., Bojesen-Koefoed, J. A., Chalmers, J. A., Dalhoff, F., Mathiesen, A., Sønderholm, M., Dam, G., Gregersen, U., Marcussen, C., Nøhr-Hansen, H., Piasecki, S., Preuss, T., Pulvertaft, T. C. R., Audun Rasmussen, J., & Sheldon, E. (2001). Petroleum geological activities in West Greenland in 2000. Geology of Greenland Survey Bulletin, 189, 24-33. https://doi.org/10.34194/ggub.v189.5150 _______________ The summer of 2000 was exciting for everyone interested in the petroleum geology and exploration of West Greenland. The first offshore well in more than 20 years was drilled by the Statoil group in the Fylla licence area, and seismic acquisition activity offshore West Greenland was more intense than previous years with four new surveys being carried out (Fig. 1). Expectations were high when drilling of the Qulleq-1 well was initiated in July 2000, not only with the licensees and the authorities, but also with the public. The well was classified as highly confidential, but nevertheless all information available was closely followed by the press, especially in Greenland and Denmark, but also internationally (see Ghexis 2000). Disappointment was equally high when the press release in September 2000 reported that the well was dry. Since that time much technical work has been carried out by Statoil and its consultants (Pegrum et al. 2001) and by the Geological Survey of Denmark and Greenland (GEUS), and a more balanced view of the positive and negative surprises from the well can now be presented.

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