scholarly journals Return migration of adult Atlantic salmon (Salmo salar L.) to northern Norway

2017 ◽  
Vol 75 (2) ◽  
pp. 653-661 ◽  
Author(s):  
Eva Marita Ulvan ◽  
Anders Foldvik ◽  
Arne Johan Jensen ◽  
Bengt Finstad ◽  
Eva Bonsak Thorstad ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
North Atlantic ◽  
Return Migration ◽  
Barents Sea ◽  
North Atlantic Ocean ◽  
Catch Per Unit Effort ◽  
Large Area ◽  
The North ◽  
Natal Homing ◽  
North And South

Abstract The return migration of adult Atlantic salmon was investigated by analysing recaptures of individuals tagged and released as smolts in the River Altaelva and the River Halselva using a catch per unit effort approach. Although the salmon were recaptured over a large area along the coastline (from >1100 km south to > 500 km northeast of their home rivers), the results indicated a relatively accurate homeward navigation for most individuals. The straying rate to rivers other than the home river was 9%. Multi-sea-winter salmon returned earlier in the season than one-sea-winter salmon, but the geographical distribution of recaptures did not differ. Recaptures were equally distributed north and south of the home rivers, implying that salmon were arriving to the coast both north and south of their home rivers and that they may have returned from different ocean areas. This was supported by the fact that several salmon were recaptured in both the southern and northern parts of the North Atlantic Ocean, including at the Faroes, south coast of Greenland, Svalbard and in the Barents Sea. This study supports the hypothesis that the coastal phase of the natal homing in migrating fish species is neither passive nor guided by currents alone.

scholarly journals Coastal migration patterns of the four largest Barents Sea Atlantic salmon stocks inferred using genetic stock identification methods

2019 ◽  
Vol 76 (6) ◽  
pp. 1379-1389 ◽  
Author(s):  
Martin-A Svenning ◽  
Morten Falkegård ◽  
Eero Niemelä ◽  
Juha-Pekka Vähä ◽  
Vidar Wennevik ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Barents Sea ◽  
Catch Per Unit Effort ◽  
Genetic Stock ◽  
Migration Patterns ◽  
The North ◽  
Genetic Stock Identification ◽  
Temporal And Spatial ◽  
Catch Composition ◽  
Mixed Stock

Abstract Combining detailed temporal and spatial catch data, including catch per unit effort, with a high-resolution microsatellite genetic baseline facilitated the development of stock-specific coastal migration models for the four largest Atlantic salmon (Salmo salar) populations, Målselv, Alta, Tana and Kola rivers, contributing to the Barents Sea mixed-stock fishery. Målselv salmon displayed a restricted coastal movement with 85% of the fish captured within 20 km of their natal river. Kola salmon also demonstrated limited coastal movements in Norwegian waters, with most (> 90%) caught in eastern Finnmark. Multi-sea-winter (MSW) Alta salmon were caught west of Alta fjord across a broader stretch of coast while one-sea-winter (1SW) fish migrated more extensively along the coast prior to river entry. Tana salmon, however, were detected over a broad expanse (600 km) of the North-Norwegian coast. For all populations MSW salmon dominating catches earlier in the season (May–June) while 1SW fish were more common from July to August. This study provides an example of how traditional catch and effort information may be combined with genetic methods to obtain insights into spatial and temporal changes in Atlantic salmon catch composition and their associated migration patterns in a mixed-stock coastal fishery.

scholarly journals Distribution of haploniscids (Isopoda, Asellota, Haploniscidae) in Icelandic waters, with description of Haploniscus astraphes n. sp. from the Iceland basin and the Southeast Atlantic Ocean

Zootaxa ◽  
2017 ◽  
Vol 4231 (3) ◽  
pp. 301 ◽  
Author(s):  
WIEBKE BRÖKELAND ◽  
JÖRUNDUR SVAVARSSON
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Strongly Convex ◽  
The North ◽  
Iceland Basin ◽  
Denmark Strait ◽  
Depth Ranges ◽  
North And South ◽  
Icelandic Waters

Ten species of Haploniscidae Hansen, 1916 were sampled in Icelandic waters during expeditions in the framework of the BIOICE project. Nine of these were known from the North Atlantic Ocean, i.e. Haploniscus aduncus Lincoln, 1985, H. ampliatus Lincoln, 1985, Haploniscus angustus Lincoln, 1985, H. bicuspis (Sars, 1877), H. foresti Chardy, 1974, H. hamatus Lincoln, 1985, H. spinifer Hansen, 1916, Antennuloniscus simplex Lincoln, 1985 and Chauliodoniscus armadilloides (Hansen, 1916). All but H. bicuspis and H. angustus were restricted to the Atlantic Ocean south of the Greenland-Iceland-Faeroe Ridge (GIF Ridge), while H. bicuspis occurred at considerable depth ranges both north and south of the GIF Ridge. A new species, Haploniscus astraphes n. sp., is described based on material from the Denmark Strait, North Atlantic and the Guinea Basin, South Atlantic. H. astraphes n. sp. belongs to a group of Haploniscus species closely related to the genus Antennuloniscus and shares several characters with species from that genus, especially the spine row on pleopod 1, the stout sensory seta on the carpus of pereopod 7 and characters of the antennae. H. astraphes n. sp. is characterized by a rectangular body shape, the straight frontal margin of the head and the strongly convex posterior margin of the pleotelson. 

scholarly journals Temporal synchrony and variation in abundance of Atlantic salmon (Salmo salar) in two subarctic Barents Sea rivers: influence of oceanic conditions

2004 ◽  
Vol 61 (12) ◽  
pp. 2384-2391 ◽  
Author(s):  
Eero Niemelä ◽  
Jaakko Erkinaro ◽  
J Brian Dempson ◽  
Markku Julkunen ◽  
Alexander Zubchenko ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
North Atlantic ◽  
Barents Sea ◽  
Seawater Temperature ◽  
Large River ◽  
Distribution Area ◽  
Climate Conditions ◽  
Atlantic Salmon Salmo Salar ◽  
The North

Long-term variation in Atlantic salmon (Salmo salar) stocks was analyzed in two Barents Sea rivers, the Teno and Näätämöjoki, that represent the northernmost distribution area of the species. In contrast to most of the North Atlantic area, these rivers are among a group of northern salmon rivers that, despite wide annual variation in catches, demonstrate no consistent trend for declining abundance. Variations in abundance were generally synchronous for the total catch and numbers of 1-sea-winter (1SW) and 2SW salmon during period of 1972–2003. Part of the variation observed in catches could be related to ocean climate conditions as the mean seawater temperature in July during the year of smoltification for the Kola section of the Barents Sea was significantly related to numbers of 1SW, 2SW, and 3SW salmon in the large River Teno. In contrast, NAO (North Atlantic Oscillation) indices were not related to salmon catches. The latest increase (1999–2001) in salmon catches in these rivers reflects both temporarily improved oceanic conditions and past management measures affecting offshore, coastal, and river fisheries.

scholarly journals Overview of the status of Atlantic salmon (Salmo salar) in the North Atlantic and trends in marine mortality

2012 ◽  
Vol 69 (9) ◽  
pp. 1538-1548 ◽  
Author(s):  
Gérald Chaput
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Minor Component ◽  
Atlantic Salmon Salmo Salar ◽  
The North ◽  
The Status ◽  
The North Atlantic ◽  
A Minor

Abstract Chaput, G. 2012. Overview of the status of Atlantic salmon (Salmo salar) in the North Atlantic and trends in marine mortality. – ICES Journal of Marine Science, 69: 1538–1548. Since the early 1980s, the ICES Working Group on North Atlantic Salmon has collated and interpreted catch data, exchanged information on research initiatives, and provided advice to managers in support of conservation efforts for Atlantic salmon. During the past three decades, the annual production of anadromous Atlantic salmon from more than 2000 rivers draining into the North Atlantic has been less than 10 million adult-sized salmon. This represents a minor component, by number and biomass, of the pelagic ecosystem in the North Atlantic Ocean. Ideally, Atlantic salmon would be assessed and managed based on river-specific stock units, the scale that best corresponds to the spawner to recruitment dynamic. In reality, comparatively few river-specific assessments are available for either the Northwest or the Northeast Atlantic. The marine survival of Atlantic salmon is low and, based on return rates of smolts to adults from monitored rivers, has declined since the mid- to late 1980s. Abundance has declined more severely for the multi-sea-winter components, and especially in the southern areas of the species' range. Common patterns in abundance, inferred at the level of stock complex in the North Atlantic, suggest that broad-scale factors are affecting productivity and abundance and that they are acting throughout the salmon's time at sea.

Hydroids (Cnidaria: Hydrozoa) recorded from depths exceeding 3000 m in the abyssal western North Atlantic

1996 ◽  
Vol 74 (9) ◽  
pp. 1721-1726 ◽  
Author(s):  
Dale R. Calder
Keyword(s):  
New England ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
South Pacific ◽  
South Atlantic ◽  
Woods Hole Oceanographic Institution ◽  
Southern New England ◽  
The North ◽  
Abyssal Zone ◽  
North And South

Hydroid diversity and abundance appear to be low in the mid-abyssal zone of the western North Atlantic Ocean. Only two species (Acryptolaria longitheca,?Opercularella sp.) were collected during investigations by submersible (Deep Submergence Vehicle Alvin) at depths between 3011 and 3550 m along the northwest slope of the Bermuda Pedestal in March 1993. Moreover, bottom samples from 59 deep stations (all > 3000 m) between southern New England and Bermuda, collected by the Woods Hole Oceanographic Institution Benthic Ecology Program between 1961 and 1973, contained just two hydroid specimens (both referred here to Halisiphonia megalotheca). Of some 424 species of hydroids currently recognized from the western North Atlantic, only 8 have ever been reported in the region from depths exceeding 3000 m. One of these (Cryptolarella abyssicola) has been recorded from the North and South Atlantic, North and South Pacific, and Southern Ocean, and another (Halisiphonia megalotheca) from the North and South Atlantic, North and South Pacific, and southern Indian Ocean. The other six (Stylactaria ingolfi, Eucuspidella pedunculata, ?Opercularella sp., Halecium dubium, Acryptolaria longitheca, and Aglaophenopsis verrilli) have been reported exclusively from the North Atlantic. The hydroid fauna of the mid-abyssal zone may be sparse compared with that of neritic waters, but it is less frequently sampled and remains poorly known.

Observed seasonal regimes of North-South Atlantic Ocean interbasin exchange

2019 ◽  
Author(s):  
Hamed D. Ibrahim
Keyword(s):  
North Atlantic ◽  
Climate Models ◽  
South Atlantic ◽  
Meridional Overturning Circulation ◽  
Volume Flux ◽  
The South ◽  
The North ◽  
Basin Scale ◽  
Interbasin Exchange ◽  
North And South

North and South Atlantic lateral volume exchange is a key component of the Atlantic Meridional Overturning Circulation (AMOC) embedded in Earth’s climate. Northward AMOC heat transport within this exchange mitigates the large heat loss to the atmosphere in the northern North Atlantic. Because of inadequate climate data, observational basin-scale studies of net interbasin exchange between the North and South Atlantic have been limited. Here ten independent climate datasets, five satellite-derived and five analyses, are synthesized to show that North and South Atlantic climatological net lateral volume exchange is partitioned into two seasonal regimes. From late-May to late-November, net lateral volume flux is from the North to the South Atlantic; whereas from late-November to late-May, net lateral volume flux is from the South to the North Atlantic. This climatological characterization offers a framework for assessing seasonal variations in these basins and provides a constraint for climate models that simulate AMOC dynamics.

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