scholarly journals Reconstruction of Atlantic herring ( Clupea harengus ) recruitment in the North Sea for the past 455 years based on the δ 13 C from annual shell increments of the ocean quahog ( Arctica islandica )

2019 ◽  
Vol 20 (3) ◽  
pp. 537-551 ◽  
Author(s):  
Juan Estrella‐Martínez ◽  
Bernd R. Schöne ◽  
Ruth H. Thurstan ◽  
Elisa Capuzzo ◽  
James D. Scourse ◽  
...  
Keyword(s):  
North Sea ◽  
Clupea Harengus ◽  
Atlantic Herring ◽  
Arctica Islandica ◽  
The Past ◽  
The North ◽  
The North Sea

Multifrequency backscattering properties of Atlantic herring (Clupea harengus) and Norway pout (Trisopterus esmarkii)

2007 ◽  
Vol 64 (2) ◽  
pp. 362-374 ◽  
Author(s):  
Sascha M.M. Fässler ◽  
Rita Santos ◽  
Norma García-Núñez ◽  
Paul G Fernandes
Keyword(s):  
North Sea ◽  
Empirical Data ◽  
Ambient Pressure ◽  
Clupea Harengus ◽  
Atlantic Herring ◽  
The North ◽  
Fish Flesh ◽  
Fishing Vessels ◽  
The North Sea ◽  
Acoustic Surveys

The multifrequency backscattering characteristics of echotraces of Atlantic herring (Clupea harengus) and Norway pout (Trisopterus esmarkii) are described. These fish cohabit similar areas of the North Sea in summer and echotraces of their schools are difficult to distinguish. Mean volume backscattering strengths at 18, 38, 120, and 200 kHz were taken from the International North Sea Herring Acoustic Surveys along with coincident pelagic trawl samples. The results indicate that echotraces of these fish species cannot be distinguished on the basis of differences in backscattering at discrete frequencies typically used in fish surveys and on fishing vessels. However, some discrimination between herring size-classes was evident. The empirical data for herring were then compared with a backscattering model for herring combining fish flesh, the swimbladder, and the effect of increased pressure at depth. Both the empirical data and model data indicate that, compared with large herring, progressively smaller herring generally have higher backscattering at the lowest frequency (18 kHz), although variability was high. According to the model, this frequency-specific signature is due to the progressively more significant contribution made by the fish body compared with the swimbladder, as the latter diminishes owing to an increase in ambient pressure in deeper water.

scholarly journals Application and validation of otolith microstructure as a stock identification method in mixed Atlantic herring (Clupea harengus) stocks in the North Sea and western Baltic

2007 ◽  
Vol 64 (2) ◽  
pp. 377-385 ◽  
Author(s):  
L. A. W. Clausen ◽  
D. Bekkevold ◽  
E. M. C. Hatfield ◽  
H. Mosegaard
Keyword(s):  
North Sea ◽  
Visual Inspection ◽  
Clupea Harengus ◽  
Classification Error ◽  
Atlantic Herring ◽  
Stock Identification ◽  
Otolith Microstructure ◽  
Identification Method ◽  
The North ◽  
The North Sea

Abstract Clausen, L. A. W., Bekkevold, D., Hatifield, E. M. C., and Mosegard, H. 2007. Application and validation of otolith microstructure as a stock identification method in mixed Atlantic herring (Clupea harengus) stocks in the North Sea and western Baltic. – ICES Journal of Marine Science, 64: 377–385. Herring (Clupea harengus) populations with different spawning times mix in ICES Division IIIa. For stock assessment, otolith microstructure analysis is used to determine the hatching season of individuals, classifying them into hatch type spring, autumn, or winter. The currently applied method uses visual inspection of season-specific daily increment pattern for the larval period. With this method, variability in individual microstructure and a lack of correspondence between hatch and spawning time may lead to classification error. We validate the visual inspection procedure in relation to these potential sources of error. Otoliths from spawning herring were first classified blindly and the results compared with spawning season. In all, 91% of classifications corresponded, and errors represented misclassifications mainly between autumn and winter spawners. However, the estimates may be biased if hatch and spawning times differ, and an objective method of hatch-time estimation based on linear modelling was employed, enumerating unbroken series of daily increments in 0-group herring hatched in different seasons. Visual inspection and objective estimation agreed in 89% of cases, and most of the errors were explained by overlapping hatch periods. Results show that herring older than the 0-group can be classified using multiple linear regression of hatch time on median increment width.

scholarly journals Comparative biology and population mixing among local, coastal and offshore Atlantic herring (Clupea harengus) in the North Sea, Skagerrak, Kattegat and western Baltic

PLoS ONE ◽  
2017 ◽  
Vol 12 (10) ◽  
pp. e0187374 ◽  
Author(s):  
Florian Berg ◽  
Aril Slotte ◽  
Arne Johannessen ◽  
Cecilie Kvamme ◽  
Lotte Worsøe Clausen ◽  
...  
Keyword(s):  
North Sea ◽  
Clupea Harengus ◽  
Comparative Biology ◽  
Atlantic Herring ◽  
Population Mixing ◽  
The North ◽  
The North Sea

scholarly journals Coastal archaeologies: settlement on the changing North Sea littoral

Antiquity ◽  
2017 ◽  
Vol 91 (358) ◽  
pp. 1095-1097
Author(s):  
Hans Peeters
Keyword(s):  
Sea Level ◽  
North Sea ◽  
British Isles ◽  
Prehistoric Archaeology ◽  
Sea Floor ◽  
The Past ◽  
The North ◽  
The North Sea ◽  
The Many ◽  
Rising Sea Level

Over the past decade or so, the submerged prehistoric archaeology and landscapes in the area that is known to us today as the North Sea have received increasing attention from both archaeologists and earth scientists. For too long, this body of water was perceived as a socio-cultural obstacle between the prehistoric Continent and the British Isles, the rising sea level a threat to coastal settlers, and the North Sea floor itself an inaccessible submerged landscape. Notwithstanding the many pertinent and pervasive problems that the archaeology of the North Sea still needs to overcome, recent research has made clear that these rather uninspiring beliefs are misplaced.

scholarly journals Inaccuracies in routinely collected Atlantic herring (Clupea harengus) maturity data and correction using a gonadosomatic index model

2011 ◽  
Vol 91 (7) ◽  
pp. 1477-1487 ◽  
Author(s):  
Lindsay R. McPherson ◽  
Konstantinos Ganias ◽  
C. Tara Marshall
Keyword(s):  
North Sea ◽  
Low Cost ◽  
Gonadosomatic Index ◽  
Clupea Harengus ◽  
Implicit Assumption ◽  
Multinomial Regression ◽  
Index Model ◽  
The North ◽  
Spawning Stock ◽  
The North Sea

Macroscopic maturity staging data are widely used to distinguish between reproductive and non-reproductive individuals. The implicit assumption is that these data are accurate. The accuracy of macroscopic maturity staging of North Sea herring (Clupea harengus) has not been checked since the macroscopic scale was produced in 1961. The aim of this study was to assess the accuracy of macroscopic maturity staging of female North Sea herring by comparison to histological staging and the gonadosomatic index (GSI). Ovary samples were collected during the North Sea Herring Acoustic Survey in 2006 on-board FRV ‘Scotia’ (Scotland) and in 2007 on-board FRV ‘Scotia’ and RV ‘Johan Hjort’ (Norway). Commercial samples were also collected by Marine Scotland, Aberdeen in both years. The maturity staging error was relatively low in 2006 (21% error) but was much higher on-board FRV ‘Scotia’ (57%) and RV ‘Johan Hjort’ (47%) in 2007. There was estimated to be a 27% under-estimation of the spawning stock biomass (SSB) in 2007 due to the differences in the proportion mature but no change in SSB estimates in 2006. GSI cut-off scores, estimated by means of multinomial regression models were successfully able to separate immature females from both mature-active and recovering females; however, there was some overlap between the mature-active and recovering individuals. We conclude that an effective and low-cost means of reducing error in herring maturity studies is the combined use of a four-point macroscopic maturity scale with routinely collected GSI data, the latter acting to validate and fine tune macroscopic staging.

Vertical distributions of autumn spawned larval herring (Clupea harengus L.) in the North Sea

1991 ◽  
Vol 11 (12) ◽  
pp. 1425-1452 ◽  
Author(s):  
M. Heath ◽  
K. Brander ◽  
P. Munk ◽  
P. Rankine
Keyword(s):  
North Sea ◽  
Clupea Harengus ◽  
The North ◽  
Vertical Distributions ◽  
The North Sea
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