Changes in Western mackerel (Scomber scombrus) spawning stock composition during the spawning season

1986 ◽  
Vol 66 (2) ◽  
pp. 367-383 ◽  
Author(s):  
Wendy A. Dawson
Keyword(s):  
North Sea ◽  
Stock Assessment ◽  
East Atlantic ◽  
The West ◽  
Scomber Scombrus ◽  
North East ◽  
The North ◽  
Spawning Stock ◽  
The North Sea ◽  
Central North Sea

INTRODUCTIONTwo groups of mackerel (Scomber scombrus L.) are recognised by the International Council for the Exploration of the Sea (I.C.E.S.) for stock assessment purposes in the north-east Atlantic. The North Sea ‘stock’, which overwinters along the edge of the Norwegian Trench and spawns off the south coast of Norway, in the Skagerrak, Kattegat and the central North Sea (Hamre, 1980), and the Western ‘stock’, which overwinters and spawns along the edge of the continental shelf from the west of Ireland to the Bay of Biscay (Lockwood, Nichols & Dawson, 1981).

Monopseudocuma a new genus from the North East Atlantic and redescription of Pseudocuma gilsoni Bacescu, 1950 (Cumacea: Pseudocumatidae)

Zootaxa ◽  
2006 ◽  
Vol 1203 (1) ◽  
pp. 39
Author(s):  
ALISON M. MCCARTHY ◽  
SARAH GERKEN ◽  
DAVID MCGRATH ◽  
GRACE P. MCCORMACK
Keyword(s):  
North Sea ◽  
West Coast ◽  
New Genus ◽  
East Atlantic ◽  
The West ◽  
The Past ◽  
North East ◽  
The North ◽  
The North Sea

The validity of Pseudocuma gilsoni B|cescu 1950 has been questioned in the past. The recent discovery of material in Irish waters, and in the North Sea, confirms the presence of the species in the North East Atlantic and provides the opportunity to present a full redescription. A new genus, Monopseudocuma, is erected to accommodate the species. A neotype is designated from the West coast of Ireland.

Exceptional influx of oceanic species into the North Sea late 1997

1999 ◽  
Vol 79 (4) ◽  
pp. 737-739 ◽  
Author(s):  
M. Edwards ◽  
A.W.G. John ◽  
H.G. Hunt ◽  
J.A. Lindley
Keyword(s):  
North Sea ◽  
Indicator Species ◽  
Climatic Conditions ◽  
Historical Evidence ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
The North Sea ◽  
Oceanic Species

Continuous Plankton Recorder records from the North Sea and north-east Atlantic from September 1997 to March 1998 indicate an exceptional influx of oceanic indicator species into the North Sea. These inflow events, according to historical evidence, have only occurred sporadically during this century. This exceptional inflow and previous inflow events are discussed in relation to their similarity in terms of their physical and climatic conditions.

scholarly journals Gadoid dynamics: differing perceptions when contrasting stock vs. population trends and its implications to management

2014 ◽  
Vol 71 (6) ◽  
pp. 1433-1442 ◽  
Author(s):  
Steven J. Holmes ◽  
Colin P. Millar ◽  
Robert J. Fryer ◽  
Peter J. Wright
Keyword(s):  
North Sea ◽  
Stock Assessment ◽  
Research Vessel ◽  
Vital Rates ◽  
The North ◽  
Depth Contour ◽  
Spawning Stock ◽  
Population Structures ◽  
The North Sea ◽  
Local Pressures

Recent research suggests that ICES stock definitions for cod, haddock, and whiting of “west of Scotland” and “North Sea”, do not reflect underlying population structures. As population responses to different vital rates and local pressures would be expected to lead to asynchrony in dynamics, we examined trends in local spawning-stock biomass (SSB) among putative subpopulations of the three species. Delineation of subpopulation boundaries around spawning time was made based on genetic, tagging, and otolith microchemistry studies together with density distributions of species based on research vessel survey data. Subpopulation specific indices of SSB were derived using numbers-at-age and maturity observations from the same research vessel data and asynchrony was assessed by fitting a smoother to log SSB for each subpopulation and testing whether the smooths were parallel. Results for cod support the hypothesis of distinct inshore and larger offshore subpopulations and for whiting for northern and southern North Sea subpopulations with a boundary associated with the 50 m depth contour. In haddock, no difference in SSB trends between the North Sea and west of Scotland was found. For cod and whiting, subpopulation SSB trends differed substantially within current stock assessment units, implying reported stock-based SSB time-series have masked underlying subpopulation trends.

Distribution, diversity and abundance of epibenthic fauna in the North Sea

1999 ◽  
Vol 79 (3) ◽  
pp. 385-399 ◽  
Author(s):  
Simon Jennings ◽  
John Lancaster ◽  
Andrew Woolmer ◽  
John Cotter
Keyword(s):  
North Sea ◽  
Temperature Difference ◽  
Free Living ◽  
North East ◽  
The North ◽  
The North Sea ◽  
Living Species ◽  
Northern North Sea ◽  
Epibenthic Fauna ◽  
Central North Sea

The assemblages of attached and freeliving epibenthic species in the North Sea are described, based on analysis of samples collected with a small beam trawl. Clustering of survey sites based on the presence or absence of attached species indicated that three regions had characteristic assemblages: the northern North Sea, the central North Sea from 55 to 57°N and the southern North Sea. Clustering of sites based on counts of free-living epibenthic species also revealed that the sites formed three major groups but these corresponded to regions in the north-east North Sea, the northern and western central North Sea and the southern and eastern central North Sea. Species which contributed most to the similarity within and dissimilarity between groups were identified. The environmental factors which best accounted for the grouping of sites were depth, winter temperature and the temperature difference between winter and summer for attached species and depth and the temperature difference between winter and summer for free-living species. The species richness of attached and free-living epibenthic species was higher in the central and northern North Sea than in the south. The number of abundant (Hill's N1) and very abundant (Hill's N2) free-living species also increased from south to north.

29 North-East Atlantic and the North Sea

2015 ◽  
Author(s):  
Long Ronán
Keyword(s):  
North Sea ◽  
Law Of The Sea ◽  
East Atlantic ◽  
Political Factors ◽  
Basic Principles ◽  
North East ◽  
The North ◽  
The North Sea ◽  
The Law ◽  
The Uk

This chapter assesses the legal regime of the North-East Atlantic and the North Sea. It begins by discussing some of the geographical, economic, environmental, strategic, and geo-political factors that are shaping the very distinctive regional regimes that give effect to the basic principles, as well as to many of the substantive provisions embodied in the UN Nations Convention on the Law of the Sea (LOSC) and related agreements. It provides a summary of the various maritime jurisdictional zones and boundaries claimed by the twelve coastal States that make-up the region: Belgium, Denmark, France, Germany, Iceland, Ireland, the Netherlands, Norway, Portugal, Spain, Sweden, and the UK. This is followed by a description of some of the principal regional bodies responsible for formulating and implementing various aspects of the law of the sea, including the regional seas environmental body, the EU and several fisheries management organizations.

Lampropidae (Crustacea: Cumacea) from the deep north-east Atlantic and the North Sea, with two new species of Hemilamprops and Mesolamprops

2007 ◽  
Vol 87 (5) ◽  
pp. 1191-1200 ◽  
Author(s):  
Salma H. Shalla ◽  
John D.D. Bishop
Keyword(s):  
New Species ◽  
North Sea ◽  
North Atlantic ◽  
First Record ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
The North Sea ◽  
The North Atlantic ◽  
A New Species

Material collected during surveys of the Atlantic Frontier Margin (north-east Atlantic) in 1996, 1998, 2000 and 2002 includes ten species of the cumacean family Lampropidae belonging to three genera. A new species of the genus Hemilamprops, H. pterini, is described. Hemilamprops cristatus is partially re-illustrated from specimens sent to A.M. Norman by G.O. Sars. A key to the North Atlantic species of Hemilamprops is provided. A new species of the genus Mesolamprops, M. hartleyi, is described from the Atlantic Frontier Margin and the North Sea. The first record of Mesolamprops denticulatus from the Atlantic is reported. A key to the species of Mesolamprops is provided. Two species of the genus Platysympus were also found. A list of other lampropid species found in the Atlantic Frontier Margin is given.

scholarly journals Emergence of a new predator in the North Sea: evaluation of potential trophic impacts focused on hake, saithe, and Norway pout

2016 ◽  
Vol 73 (5) ◽  
pp. 1370-1381 ◽  
Author(s):  
Xochitl Cormon ◽  
Alexander Kempf ◽  
Youen Vermard ◽  
Morten Vinther ◽  
Paul Marchal
Keyword(s):  
North Sea ◽  
Negative Impact ◽  
Stock Assessment ◽  
Single Species ◽  
Bottom Up ◽  
The North ◽  
Spatial Shift ◽  
Spawning Stock ◽  
The North Sea ◽  
Indirect Impacts

Abstract During the last 15 years, northern European hake (Merluccius merluccius) has increased in abundance, and its spatial distribution has expanded in the North Sea region in correlation with temperature. In a context of global warming, this spatial shift could impact local trophic interactions: direct impacts may affect forage fish through modified predator–prey interactions, and indirect impacts may materialize through competition with other resident predators. For instance, North Sea saithe (Pollachius virens) spatial overlap with hake has increased while saithe spawning-stock biomass has decreased recently notwithstanding a sustainable exploitation. In this context, we investigated the range of potential impacts resulting from most recent hake emergence in the North Sea, with a particular focus on saithe. We carried out a multispecies assessment of North Sea saithe, using the Stochastic MultiSpecies (SMS) model. In addition to top-down processes already implemented in SMS, we built in the model bottom-up processes, relating Norway pout (Trisopterus esmarkii) abundance and saithe weight-at-age. We simulated the effects, on all North Sea species being considered but focusing on Norway pout and saithe, of combining different hake abundance trends scenarios with the inclusion of bottom-up processes in SMS. North Sea saithe FMSY was then evaluated in a multispecies context and contrasted with single-species value. The different scenarios tested revealed a negative impact of hake emergence on saithe biomass, resulting from an increase of predation pressure on Norway pout. These results confirm the competition assumption between saithe and hake in the North Sea and might partially explain the most recent decrease of saithe biomass. This study also highlighted that taking into account bottom-up processes in the stock assessment had a limited effect on the estimation of saithe FMSY which was consistent with single-species value.

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