Does population genetic structure support present management regulations of the northern shrimp (Pandalus borealis) in Skagerrak and the North Sea?

Abstract Population structuring in the northern shrimp (Pandalus borealis) in the North Sea area (including Fladen and Skagerrak) was studied by microsatellite DNA analyses. Screening 20 sample locations in the open ocean and Skagerrak fjords for nine loci revealed low, but significant genetic heterogeneity. The spatial genetic structure among oceanic samples of Skagerrak and the eastern North Sea was weak and non-significant, consistent with the current management regime of one single stock. However, Skagerrak fjord samples generally displayed elevated levels of genetic differentiation, and significantly so in several pairwise comparisons with other fjords and oceanic samples. Although the Skagerrak fjord populations are of less economic value, some of them are regulated separately (e.g. the Gullmarsfjord) and local stocks may prove important to uphold genetic variability and biocomplexity in a changing environment.

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Fish population structuring in the North Sea: understanding processes and mechanisms from studies of the movements of adults

Journal of Fish Biology ◽

10.1111/j.1095-8649.2006.01275.x ◽

2006 ◽

Vol 69 (sc) ◽

pp. 48-65 ◽

Cited By ~ 45

Author(s):

J. D. Metcalfe

Keyword(s):

North Sea ◽

Fish Population ◽

The North ◽

Population Structuring ◽

The North Sea

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Integrating the scale of population processes into fisheries management, as illustrated in the sandeel, Ammodytes marinus

ICES Journal of Marine Science ◽

10.1093/icesjms/fsz013 ◽

2019 ◽

Vol 76 (6) ◽

pp. 1453-1463 ◽

Cited By ~ 5

Author(s):

P J Wright ◽

A Christensen ◽

T Régnier ◽

A Rindorf ◽

M van Deurs

Keyword(s):

Fisheries Management ◽

North Sea ◽

Larval Transport ◽

Biophysical Model ◽

Distribution Data ◽

Management Actions ◽

The North ◽

Management Regime ◽

Class Strength ◽

The North Sea

Abstract Aggregations of site-attached populations can show marked differences in density due to variation in local productivity and mortality processes. Matching management actions to the scale of biological processes is therefore important for sustainable fisheries management. This study examined the adequacy and appropriate scale of a spatially explicit management regime for sandeel, Ammodytes marinus, in the North Sea. Information from biophysical model simulations of larval transport and otolith chemistry was used to estimate the scale of mixing among aggregations. Together, these approaches indicated that there was negligible exchange of pre-settled sandeel among aggregations >200 km apart. Additionally, a re-analysis of tag-recapture experiments and distribution data indicated that the dispersive range decreased further after settlement. Significant differences in length at maturity and year-class strength not only reflect the limited mixing across the North Sea, but also point to regional differences in productivity and thereby vulnerability to fishing pressure. We conclude that the current management regime comprised of multiple assessment areas enable these differences to be considered in advice on annual fishing quotas.

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Population Genetic Structure Is Unrelated to Shell Shape, Thickness and Organic Content in European Populations of the Soft-Shell Clam Mya Arenaria

Genes ◽

10.3390/genes11030298 ◽

2020 ◽

Vol 11 (3) ◽

pp. 298 ◽

Cited By ~ 2

Author(s):

Michele De Noia ◽

Luca Telesca ◽

David L. J. Vendrami ◽

Hatice K. Gokalp ◽

Grégory Charrier ◽

...

Keyword(s):

Population Structure ◽

Genetic Structure ◽

North Sea ◽

Organic Content ◽

Mya Arenaria ◽

Shell Shape ◽

Soft Shell Clam ◽

The North ◽

Soft Shell ◽

The North Sea

The soft-shell clam Mya arenaria is one of the most ancient invaders of European coasts and is present in many coastal ecosystems, yet little is known about its genetic structure in Europe. We collected 266 samples spanning a latitudinal cline from the Mediterranean to the North Sea and genotyped them at 12 microsatellite loci. In parallel, geometric morphometric analysis of shell outlines was used to test for associations between shell shape, latitude and genotype, and for a selection of shells we measured the thickness and organic content of the granular prismatic (PR), the crossed-lamellar (CL) and the complex crossed-lamellar (CCL) layers. Strong population structure was detected, with Bayesian cluster analysis identifying four groups located in the Mediterranean, Celtic Sea, along the continental coast of the North Sea and in Scotland. Multivariate analysis of shell shape uncovered a significant effect of collection site but no associations with any other variables. Shell thickness did not vary significantly with either latitude or genotype, although PR thickness and calcification were positively associated with latitude, while CCL thickness showed a negative association. Our study provides new insights into the population structure of this species and sheds light on factors influencing shell shape, thickness and microstructure.

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Chapter II. Medium-Term Policy Options

National Institute Economic Review ◽

10.1177/002795017708200103 ◽

1977 ◽

Vol 82 ◽

pp. 20-25

Keyword(s):

North Sea ◽

Oil And Gas ◽

Economic Value ◽

Policy Options ◽

Medium Term ◽

The North ◽

The North Sea

In a special article in this Review (pp. 41–58), S. A. B. Page sets out estimates of various aspects of the production and economic value of North Sea oil and gas. In this chapter we consider some of the policy options which are opened up for the next four years in the light of the development of the North Sea resources.

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