scholarly journals North Sea herring (Clupea harengus L.) recruitment failure may be indicative of poor feeding success

2014 ◽  
Vol 71 (8) ◽  
pp. 2026-2041 ◽  
Author(s):  
Susan Mærsk Lusseau ◽  
Alejandro Gallego ◽  
Jens Rasmussen ◽  
Emma M. C. Hatfield ◽  
Mike Heath
Keyword(s):  
North Sea ◽  
Parasite Prevalence ◽  
Clupea Harengus ◽  
Gut Contents ◽  
Larval Population ◽  
Feeding Success ◽  
Recruitment Failure ◽  
The North ◽  
History Of ◽  
The North Sea

Abstract Recruitment of the 2002–2012 year classes to the North Sea herring stock has been below expectations given the spawning biomass, due to exceptionally low overwinter survival of larvae. Here, we investigate whether changes in survival of larvae in the northwestern North Sea could be attributed to changes in parasite prevalence or feeding conditions. We used a method that combined particle tracking models and survey data to estimate survival, and microscopic examination of gut contents of archived samples of larvae collected in February each year between 1995 and 2007 to investigate parasite prevalence and feeding. We deduced that we can use the incidence of tetraphyllidean parasites as an index of the cumulative feeding history of the larval population. We found that the prevalence of larvae of a tetraphyllidean cestode in the gut contents varied significantly between years and was positively correlated with feeding success. High feeding success, indicated by high prevalence of tetraphyllideans, influenced survival by offsetting the effect of a second parasite type, a digenean trematode. We suggest that variability in cumulative food intake over the lifespan up to February is a significant determinant of variability in survival.

A Case History of Casing Directional Drilling in the Norwegian Sector of the North Sea

2008 ◽  
Author(s):  
Kevin Arthur Bourassa ◽  
Tove Husby ◽  
Rick Deuane Watts ◽  
Dale Oveson ◽  
Tommy M. Warren ◽  
...  
Keyword(s):  
North Sea ◽  
Case History ◽  
Directional Drilling ◽  
The North ◽  
History Of ◽  
The North Sea

The history and future of the North Sea benthos

1978 ◽  
Vol 76 (1-3) ◽  
pp. 193-200
Author(s):  
P. E. P. Norton
Keyword(s):  
North Sea ◽  
Bottom Type ◽  
The North ◽  
Late Tertiary ◽  
Long Term Changes ◽  
History Of ◽  
The North Sea ◽  
Temperature Depth

SynopsisThis is a brief review intended to supply bases for prediction of future changes in the North Sea Benthos. It surveys long-term changes which are affecting the benthos. Any prediction must take into account change in temperature, depth, bottom type, tidal patterns, current patterns and zoogeography of the sea and the history of these is briefly touched on from late Tertiary times up to the present. From a prediction of changes in the benthos, certain information concerning the pelagic and planktonic biota could also be derived.

Clay mineral distribution and provenance in Mesozoic and Tertiary mudrocks of the Moray Firth and northern North Sea

Clay Minerals ◽  
1990 ◽  
Vol 25 (4) ◽  
pp. 519-541 ◽  
Author(s):  
M. J. Pearson
Keyword(s):  
Clay Mineral ◽  
North Sea ◽  
Volcanic Activity ◽  
Volcanic Material ◽  
The North ◽  
Moray Firth ◽  
History Of ◽  
The North Sea ◽  
Northern North Sea ◽  
And Control

AbstractClay mineral abundances in Mesozoic and Tertiary argillaceous strata from 15 exploration wells in the Inner and Outer Moray Firth, Viking Graben and East Shetland Basins of the northern North Sea have been determined in <0·2 µm fractions of cuttings samples. The clay assemblages of more deeply-buried samples cannot be unambiguously related to sedimentary input because of the diagenetic overprint which may account for much of the chlorite and related interstratified minerals. Other sediments, discussed on a regional basis and related to the geological history of the basins, are interpreted in terms of clay mineral provenance and control by climate, tectonic and volcanic activity. The distribution of illite-smectite can often be related to volcanic activity both in the Forties area during the M. Jurassic, and on the NE Atlantic continental margin during the U. Cretaceous-Early Tertiary which affected the North Sea more widely and left a prominent record in the Viking Graben and East Shetland Basin. Kaolinite associated with lignite-bearing sediments in the Outer Moray Firth Basin was probably derived by alteration of volcanic material in lagoonal or deltaic environments. Some U. Jurassic and L. Cretaceous sediments of the Inner Moray Basin are rich in illite-smectite, the origin of which is not clear.

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

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.

Case history of a six‐streamer seismic survey in the North Sea

1991 ◽  
Author(s):  
Gary Hampson ◽  
Terje Hansen ◽  
H. Jakubowicz ◽  
John V. Kingston
Keyword(s):  
North Sea ◽  
Case History ◽  
Seismic Survey ◽  
The North ◽  
History Of ◽  
The North Sea

scholarly journals OSPAR Ecological Quality Objectives: the utility of health indicators for the North Sea

2008 ◽  
Vol 65 (8) ◽  
pp. 1392-1397 ◽  
Author(s):  
Peter Heslenfeld ◽  
E. Lisette Enserink
Keyword(s):  
North Sea ◽  
Health Indicators ◽  
Ecosystem Approach ◽  
Current Status ◽  
Test Case ◽  
Ecological Quality ◽  
Marine Research ◽  
The North ◽  
History Of ◽  
The North Sea

Abstract Heslenfeld, P., and Enserink, E. L. 2008. OSPAR Ecological Quality Objectives: the utility of health indicators for the North Sea. – ICES Journal of Marine Science, 65: 1392–1397. Committed to the ecosystem approach to management, OSPAR has accumulated 15 years of experience in developing a conceptual framework for ecological indicators and objectives, and in applying the framework to the North Sea as a test case. These Ecological Quality Objectives (EcoQOs) have become a model for the implementation of the new European Marine Strategy Framework Directive. We describe the history of EcoQO development, its current status, and future needs. We also present our positive and negative experiences in developing the approach, and conclude that regional sea conventions and marine research institutes in Europe should join forces to accelerate the development of ecosystem indicators and objectives, using existing concepts.

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