scholarly journals Spawning location of Norway pout (Trisopterus esmarkii Nilsson) in the North Sea

2012 ◽  
Vol 69 (8) ◽  
pp. 1338-1346 ◽  
Author(s):  
Richard D. M. Nash ◽  
Peter J. Wright ◽  
Iveta Matejusova ◽  
Stefan Petev Dimitrov ◽  
Martha O'Sullivan ◽  
...  
Keyword(s):  
North Sea ◽  
Size Range ◽  
Northern Region ◽  
Stage I ◽  
The South ◽  
The North ◽  
Spawning Areas ◽  
The North Sea ◽  
Merlangius Merlangus ◽  
North Western

Abstract Nash, R. D. M., Wright, P. J., Matejusova, I., Dimitrov, S. P., O'Sullivan, M., Augley, J., and Höffle, H. 2012. Spawning location of Norway pout (Trisopterus esmarkii Nilsson) in the North Sea. – ICES Journal of Marine Science, 69: . The northern region of the North Sea (56–62°N) was sampled in February/March 2009 for eggs and in May 2010 for larvae. To aid in the identification of Norway pout stage I eggs and distinguish them from other ‘cod-like’ eggs, a Taq-Man probe was designed for this species and used here. Stage I Norway pout egg diameters collected from the field were in the range 1.03–1.28 mm and largely overlapped with the size range determined for whiting (Merlangius merlangus). The distribution of Norway pout stage I eggs in 2009 revealed the distribution of spawning in the North Sea and showed that it was similar to the distribution of 2 + Norway pout taken during the International Bottom Trawl Surveys (IBTS) over the same period covering the whole North Sea. The larvae sampled in 2010 were largely in the same area; however, larger larvae occurred to the south-east of the survey area, suggesting advection of young stages from the principal spawning areas in the north-western North Sea to the south-east and toward the Skagerrak.

scholarly journals Earthquake in Denmark

1998 ◽  
Vol 44 ◽  
pp. 115-127
Author(s):  
Søren Gregersen ◽  
Jørgen Hjelme ◽  
Erik Hjortenberg
Keyword(s):  
North Sea ◽  
Border Zone ◽  
Earthquake Activity ◽  
Spreading Ridge ◽  
The South ◽  
The North ◽  
General Terms ◽  
The North Sea ◽  
Earthquake Zone ◽  
North Western

Within the last two decades the sensitivity to small earthquakes has been much improved in Denrnark. Two to ten earthquakes are recorded each year of magnitudes 1% to 4%. The seismicity pattem seen in recent data basically confirms the patterns noted from previous instrumental locations, as well as from felt areas of older dates. This means earthquake activity cutting off the earthquake zones of western Nonvay and of southem Sweden: (1) In north-western Jylland, and in the Skagerrak Sea the earthquake zone cuts off a zone of earthquakes along the western coast of Norway. At least some of these earthquakes in Jylland and Skagerrak occur at depths 30-40 km, close to Moho. (2) In north-eastern Sjaelland and in the Kattegat Sea, as well as around Bornholm the earthquake activity occurs in the upper crust, at depths shallower than 15 km. This appears as the south-western boundary of the scattered activity in south-western Sweden. In general terms this can be considered the south-western rheological edge of the Fennoscandian Shield. The north-western earthquake zone is along the middle axis of the Norwegian-Danish Basin, and the eastern earthquake zone is in the Tornquist Zone. The two earthquake zones are not connected. This can not be ascribed to lack of sensitivity, so the Fennoscandian Border Zone can not be termed active as such. The central part of Denrnark is aseisrnic; and the same is true for the south-western part of Denmark and northern Germany. In the North Sea the graben area is the most active. The Viking Graben in the north has a significant earthquake activity, and the Central Graben, which goes through the Danish sector of the North Sea has small, but noticeable activity. On the British side of the graben there are additional active areas. The stress field responsible for these earthquakes is rather uniform across the Fennoscandian Border Zone, with scattered exceptions. It reflects the general NW-SE compression of northem Europe between the North Atlantic spreading ridge and the Alpine collision between Europe and Africa.

The case for comparison

2007 ◽  
Author(s):  
Anne Haour
Keyword(s):  
North Sea ◽  
Western Europe ◽  
North West ◽  
The North ◽  
The North Sea ◽  
North Western

This chapter explains the coverage of this book, which is about the comparison of rulers, warriors, traders, and clerics on the central Sahel and the North Sea region. It argues that there was more similarity between north-western Europe and the central Sahel in the few centuries either side of AD 1001 than has hitherto been recognised, and maintains that the nature of the sources has obscured these formative times and left them in the shadow of organised structures. It discusses the interconnectedness of central Sahel and north-west Europe through contacts and shared pre-industrial nature.

scholarly journals IX.—On the Glacial Succession in Europe

1895 ◽  
Vol 37 (1) ◽  
pp. 127-149
Author(s):  
James Geikie
Keyword(s):  
North Sea ◽  
Western Europe ◽  
Climatic Conditions ◽  
Marine Origin ◽  
The North ◽  
Pleistocene Period ◽  
The North Sea ◽  
North Western

For many years geologists have recognised the occurrence of at least two boulder-clays in the British Islands and the corresponding latitudes of the Continent. It is no longer doubted that these are the products of two separate and distinct glacial epochs. This has been demonstrated by the appearance of intercalated deposits of terrestrial, freshwater, or, as the case may be, marine origin. Such interglacial accumulations have been met with again and again in Britain, and they have likewise been detected at many places on the Continent, between the border of the North Sea and the heart of Russia. Their organic contents indicate in some cases cold climatic conditions; in others, they imply a climate not less temperate or even more genial than that which now obtains in the regions where they occur. Nor are such interglacial beds confined to northern and north-western Europe. In the Alpine Lands of the central and southern regions of our Continent they are equally well developed. Impressed by the growing strength of the evidence, it is no wonder that geologists, after a season of doubt, should at last agree in the conclusion that the glacial conditions of the Pleistocene period were interrupted by at least one protracted interglacial epoch. Not a few observers go further, and maintain that the evidence indicates more than this. They hold that three or even more glacial epochs supervened in Pleistocene times. This is the conclusion I reached many years ago, and I now purpose reviewing the evidence which has accumulated since then, in order to show how far it goes to support that conclusion.

scholarly journals Tunny Investigations made in the North Sea on Col. E. T. Peel's Yacht, “St. George,” Summer, 1933. Part I. Biometric Data

1934 ◽  
Vol 19 (2) ◽  
pp. 503-522 ◽  
Author(s):  
F. S. Russell
Keyword(s):  
North Sea ◽  
South Coast ◽  
Body Proportions ◽  
The South ◽  
Biometric Data ◽  
The North ◽  
The North Sea ◽  
Sea Fish ◽  
Made In

1. Details are given of the types of hooks lost in tunny in the North Sea in the summer of 1933.2. Data are given on the measurements made on thirty-two large migrating fish caught in the North Sea in August and September, 1933.3. In certain body proportions the tunny measured differ from those in the G4 Group (200 to 260 cm. in length) given by Heldt for fish from Tunis and by Frade for fish from Algarve on the south coast of Portugal, while in some characters they resemble the Tunis fish and in others the Algarve fish, but all the North Sea fish were between 232 and 271 cm. in length.4. It was found that there was a tendency for fish with short second dorsal fins to have short first dorsal, anal, and caudal fins, and for those with long second dorsals to have these other three fins long.5. Measurements were made to supply data on the condition of the fish.

scholarly journals III.—On the Structure of the Valleys of the Blackwater and the Crough, and of the East Essex Gravel, and on the Relation of this Gravel to the Denudation of the Weald

1866 ◽  
Vol 3 (26) ◽  
pp. 348-354 ◽  
Author(s):  
Searles V. Wood
Keyword(s):  
North Sea ◽  
Glacial Period ◽  
The South ◽  
Northern Boundary ◽  
The North ◽  
Complete Order ◽  
The North Sea ◽  
Boulder Clay ◽  
London Clay

In a paper in this Magazine, upon the structure of the Thames Valley, I endeavoured to show that instead of being, as had been asserted, a valley of similar structure to those of the Somme and Seine, and containing deposits of nearly similar order and age, the valley in which the Thames gravel was deposited possessed no outlet to what is now the North Sea, being divided from it by a range of high gravelless country; and that, in lieu of such an outlet, the valley opened, in more than one part, over what is now the bare Chalk country forming the northern boundary of the Valley of the Weald. I also endeavoured to show that all the deposits of the Thames Valley, except the peat and marsh clay, belonged to several successive stages, marking the gradual denudation of the Boulderclay, the lower Bagshot, the London Clay, and the subjacent Tertiaries, which had, at the end of the Glacial period, spread over the south-east of England in a complete order of succession: the sea into which this valley discharged occupying, what is now, the Chalk country of the Counties of Kent, Surrey, Sussex, and Hampshire, inclusive of the interval subsequently scooped out to form the Valley of the Weald: so that, not only was the latter valley newer than that of the Thames, and of the most recent of the Thames Valley deposits, except the peat and marsh clay, but that these deposits in themselves marked a long descent in time from that comparatively remote period of the Boulder-clay.

Cold Induced Abnormal Catches of Sole

1998 ◽  
Vol 78 (1) ◽  
pp. 345-347 ◽  
Author(s):  
J.W. Horwood ◽  
R.S. Millner
Keyword(s):  
North Sea ◽  
Cold Water ◽  
The South ◽  
Total Allowable Catch ◽  
The North ◽  
Solea Solea ◽  
The North Sea ◽  
The Uk ◽  
The Eu ◽  
Made In

Large catches of sole (Solea solea) were made in early 1996 from the south-western North Sea. Sole suffer physiological damage in waters below 3–4 C. In February 1996 cold water of 3–4 C unusually extended from the Continental coast onto the Dogger Bank. It is likely that the increased catches were due to the consequential distribution and behaviour of the sole, making them more susceptible to capture.Exceptionally large catches of mature sole (Solea solea (L.)) were made in February 1996 by Lowestoft fishermen from the south-western North Sea. Surprisingly this was not welcome. The UK allocation of the North Sea sole is -4 % of the EU Total Allowable Catch (TAC), and fishermen are restricted nationally, and by the fishing companies, to a tightly managed ration. The Lowestoft Journal (8 March 1996) reported the suspension of a local fishing skipper for not throwing back 5000 kg of sole caught in the Silver Pits. We will show that the abnormal catches were due to exceptionally cold waters.Sole in the North Sea are at the northern extremity of their range, with sole seldom living in waters below 5°C (Horwood, 1993). In fact, North Sea sole were successfully introduced into Lake Quarun, Egypt, where they lived in temperatures in excess of 30°C (El-Zarka, 1965). Young sole migrate from their shallow inshore nursery grounds, such as the Waddensea, as winter approaches (Creutzberg & Fonds, 1971).

Harbour porpoises (Phocoena phocoena) in north-western France: aerial survey, opportunistic sightings and strandings monitoring

2009 ◽  
Vol 89 (5) ◽  
pp. 1045-1050 ◽  
Author(s):  
J.-L. Jung ◽  
E. Stéphan ◽  
M. Louis ◽  
E. Alfonsi ◽  
C. Liret ◽  
...  
Keyword(s):  
North Sea ◽  
Aerial Survey ◽  
Harbour Porpoise ◽  
Shallow Waters ◽  
Encounter Rate ◽  
English Channel ◽  
Phocoena Phocoena ◽  
The North ◽  
The North Sea ◽  
North Western

The harbour porpoise (Phocoena phocoena) is one of the common small cetaceans of European waters. This discreet and undemonstrative species is strongly represented throughout the cold waters of the northern hemisphere, and is the most abundant cetacean in the North Sea. In the last few years, some observations and studies indicate a shift of harbour porpoise distribution in European waters, from northern regions of the North Sea to the southern North Sea, English Channel and Celtic Sea. This shift may include a comeback around the coasts of France. Harbour porpoises inhabit shelf-waters and are often observed in shallow waters, conditions offered for instance by the coasts of Brittany in north-western France. We used opportunistic sightings, aerial survey and a ten-year strandings database to study the presence of harbour porpoises along the coasts of Brittany. Opportunistic sightings made by non-specialists did not confirm a strong presence of harbour porpoises along the Brittany coasts, most probably because of the undemonstrative behaviour of this cetacean. However, aerial survey and stranding analysis indicate that harbour porpoises have become natural inhabitants of the Brittany coasts once more: 68.6% of cetacean school sightings made during a 1578 km aerial survey of the Brittany coasts concerned harbour porpoises, with an encounter rate of 1.5 individuals per 100 km that peaked to 5.8 per 100 km to the top of the shallow waters of the south-western Western English Channel. The number of harbour porpoise strandings increased each year from 1997 to 2007, making a total of 135 along the coasts of Brittany. Other cetaceans did not show such an increase during the same period. Strandings of harbour porpoises were also characterized by an apparent increase as a proportion in relation to all the cetacean strandings during the months of September to January, by a marked impact of by-catch during winter, and by an almost total absence of stranded calves. The comeback of the harbour porpoise along Brittany coasts is clearly confirmed by our data, and a stable population seems to be established again along the coasts of Brittany. This tends to confirm the shift of the distribution of the species in certain European waters. Long term monitoring, diet and genetic studies are now planned for a better understanding of this shift, and for the effective implementation of a conservation plan.

scholarly journals THE DUTCH PROGRAM OF INVESTIGATIONS ON STORM SURGES IN THE NORTH SEA

2011 ◽  
Vol 1 (5) ◽  
pp. 34
Author(s):  
J. B. Schijf
Keyword(s):  
The Netherlands ◽  
North Sea ◽  
Storm Surges ◽  
Water Levels ◽  
Wind Effects ◽  
Shallow Sea ◽  
The North ◽  
The North Sea ◽  
Western Germany ◽  
North Western

The North Sea is a shallow sea and therefore it is very sensitive to wind effects. As a result the water levels along the coasts are, in addition to the tidal oscillations subject to a considerable wind setup and exceptionally severe gales throughout history have been accompanied by inundations of the low-lying regions bordering the North Sea, in particular its southern part. No stretch of coast has suffered more than that belonging to the Netherlands and the adjacent parts of Belgium and North Western Germany. Several factors combine to bestow on us this doubtful privilege.

scholarly journals Do Norway pout (Trisopterus esmarkii) die from spawning stress? Mortality of Norway pout in relation to growth, sexual maturity, and density in the North Sea, Skagerrak, and Kattegat

2012 ◽  
Vol 69 (2) ◽  
pp. 197-207 ◽  
Author(s):  
J. Rasmus Nielsen ◽  
Gwladys Lambert ◽  
Francois Bastardie ◽  
Henrik Sparholt ◽  
Morten Vinther
Keyword(s):  
North Sea ◽  
Sexual Maturity ◽  
Life History Traits ◽  
Trawl Survey ◽  
Older Individuals ◽  
Fishing Activity ◽  
The North ◽  
Spawning Areas ◽  
The North Sea ◽  
New Evidence

Abstract Nielsen, J. R., Lambert, G., Bastardie, F., Sparholt, H., and Vinther, M. 2012. Do Norway pout (Trisopterus esmarkii) die from spawning stress? Mortality of Norway pout in relation to growth, sexual maturity, and density in the North Sea, Skagerrak, and Kattegat. – ICES Journal of Marine Science, 69: 197–207. The mortality patterns of Norway pout (NP) are not well understood. It has been suggested that NP undergo heavy spawning mortality, and this paper summarizes and provides new evidence in support of this hypothesis. The very low–absent fishing activity in recent years provides a unique opportunity to analyse the natural life-history traits of cohorts in the NP stock in the North Sea. Based on the ICES trawl survey abundance indices, cohort mortality is found to significantly increase with age. We argue that this cannot be explained by selectiveness in the fishery, potential size-specific migrations out of the area, higher predation pressure on older individuals, or differences in survey catchability by NP age from before to after spawning and that it is higher in the main spawning areas than outside. We found that natural mortality (M) is significantly correlated with sexual maturity, sex, growth, and intraspecific stock density. All of this is consistent with a greater mortality occurring mainly from the first to the second quarter of the year, i.e. spawning mortality, which is discussed as being a major direct and indirect cause of stock mortality.

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