Geographic variation in allele frequencies at three loci in Chlamys opercularis from Norway to the Brittany coast

1982 ◽  
Vol 62 (2) ◽  
pp. 243-261 ◽  
Author(s):  
A. R. Beaumont
Keyword(s):  
Geographic Variation ◽  
Leucine Aminopeptidase ◽  
Allele Frequencies ◽  
Irish Sea ◽  
Coastal Current ◽  
Isolated Populations ◽  
Protein Locus ◽  
The Irish Sea ◽  
Current Systems ◽  
Octopine Dehydrogenase

Geographic variation of allele frequencies at four loci in Chlamys opercularis was investigated using electrophoresis on polyacrylamide gels. Large differences were observed between populations at a protein locus, while some small but significant variations occurred at the phosphoglucomutase-2 and octopine dehydrogenase loci. The leucine aminopeptidase locus appeared monomorphic. On the basis of mean genetic identities derived from three loci in nine populations and hydrographic data on coastal current systems, it is proposed that there are at least four relatively genetically isolated populations of this scallop around the British Isles, namely (1) North and West Scottish coast, (2) the Irish Sea, (3) the Celtic Sea (Brittany coast) and (4) the English Channel. It is argued that both random genetic drift and selection may play a significant part in the establishment and retention of large allele frequency differences between isolated populations of this species.

scholarly journals Identification of genetically and oceanographically distinct blooms of jellyfish

2013 ◽  
Vol 10 (80) ◽  
pp. 20120920 ◽  
Author(s):  
Patricia L. M. Lee ◽  
Michael N Dawson ◽  
Simon P. Neill ◽  
Peter E. Robins ◽  
Jonathan D. R. Houghton ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Interdisciplinary Approach ◽  
Irish Sea ◽  
Isolated Populations ◽  
Significant Genetic Structure ◽  
Jellyfish Blooms ◽  
The Irish Sea ◽  
Scyphozoan Jellyfish ◽  
Regional Processes ◽  
Northeastern Atlantic

Reports of nuisance jellyfish blooms have increased worldwide during the last half-century, but the possible causes remain unclear. A persistent difficulty lies in identifying whether blooms occur owing to local or regional processes. This issue can be resolved, in part, by establishing the geographical scales of connectivity among locations, which may be addressed using genetic analyses and oceanographic modelling. We used landscape genetics and Lagrangian modelling of oceanographic dispersal to explore patterns of connectivity in the scyphozoan jellyfish Rhizostoma octopus , which occurs en masse at locations in the Irish Sea and northeastern Atlantic. We found significant genetic structure distinguishing three populations, with both consistencies and inconsistencies with prevailing physical oceanographic patterns. Our analyses identify locations where blooms occur in apparently geographically isolated populations, locations where blooms may be the source or result of migrants, and a location where blooms do not occur consistently and jellyfish are mostly immigrant. Our interdisciplinary approach thus provides a means to ascertain the geographical origins of jellyfish in outbreaks, which may have wide utility as increased international efforts investigate jellyfish blooms.

Hydrographic Observations in the Eastern Irish Sea With Particular Reference to the Distribution of Nutrient Salts

1971 ◽  
Vol 51 (1) ◽  
pp. 159-182 ◽  
Author(s):  
P. G. W. Jones ◽  
A. R. Folkard
Keyword(s):  
Organic Phosphorus ◽  
Irish Sea ◽  
Liverpool Bay ◽  
Isle Of Man ◽  
Phosphate Nitrate ◽  
Distribution And Ecology ◽  
The Irish Sea ◽  
Physical And Chemical ◽  
Current Systems ◽  
Made In

INTRODUCTIONStudies on the physical hydrography of the Irish Sea, based mainly on temperature and salinity observations, have been made by Bowden (1955) and Lee (1960). The current systems in various parts of the Irish Sea have been investigated by Bowden & Sharaf El Din (1966), Harvey (1968), Ramster & Hill (1969) and Hill & Ramster (1971). Various smaller-scale physical observations made by other workers have been listed by the above authors.There are not as many references in the literature to the distribution of nutrient salts in the Irish Sea. Jones & Haq (1963) measured phosphate in Liverpool Bay as part of an investigation into the distribution of the alga Phaeocystis. Slinn & Offlow (1968) have made regular routine measurements of phosphate, nitrate and silicate over a number of years off Port Erin, Isle of Man. Ewins & Spencer (1967) measured phosphate, organic phosphorus, nitrate and silicate in the Menai Straits, and Liss (1969) surveyed the distribution of silicate in the western Irish Sea.During recent years the Fisheries Laboratory at Lowestoft has investigated the distribution and ecology of plankton and larval plaice in the Irish Sea, and a supporting programme of both physical and chemical hydrographic observations has been made in the area. Ramster & Hill (1969) and Hill & Ramster (1971) have summarized the results of the Lowestoft current measurements. The present paper describes an investigation into the distribution of temperature, salinity, phosphate, nitrate and silicate. The occurrence of Phaeocystis is also reported as an extension of the earlier work by Jones & Haq (1963).

The medieval cultures of the Irish sea and the North Sea: Manannan and his neighbors [Book Review]

2019 ◽  
Vol 15 ◽  
pp. 142-144
Author(s):  
John Kennedy
Keyword(s):  
North Sea ◽  
Irish Sea ◽  
The North ◽  
The North Sea ◽  
The Irish Sea

Review(s) of: The medieval cultures of the Irish sea and the North Sea: Manannan and his neighbors, by MacQuarrie, Charles W., and Nagy, Joseph Falaky Nagy (eds), (Amsterdam: Amsterdam University Press, 2019) hardcover, 212 pages, 1 map, 4 figures, RRP euro99; ISBN 9789462989399.

scholarly journals Morphological abnormality in thornback ray Raja clavata in the Irish Sea

2021 ◽  
Author(s):  
L. J. Clarke
Keyword(s):  
Irish Sea ◽  
Beam Trawl ◽  
Morphological Abnormality ◽  
Free Swimming ◽  
Pectoral Fins ◽  
North Wales ◽  
Head Section ◽  
Thornback Ray ◽  
Raja Clavata ◽  
The Irish Sea

AbstractA free-swimming thornback ray Raja clavata specimen demonstrating significant morphological abnormality is reported, captured by beam trawl in the Irish Sea off north Wales, UK. The anterior sections of both pectoral fins were separated from the head section for a length of approximately 140 mm extending from the rostrum tip to a point posterior of the spiracles, along with abnormal morphology of the gill slits. This phenomenon has been observed elsewhere but is the first documented example of this abnormality in the eastern Irish Sea, despite widespread targeting of the species across the region by commercial and recreational fishers. Possible causes and consequences of the observed abnormality are discussed.

A detailed comparison of measured and modeled wind-driven currents in the North Channel of the Irish Sea

2001 ◽  
Vol 106 (C9) ◽  
pp. 19683-19713 ◽  
Author(s):  
Alan M. Davies ◽  
Philip Hall ◽  
M. John Howarth ◽  
Philip Knight ◽  
Rose Player
Keyword(s):  
Detailed Comparison ◽  
Irish Sea ◽  
The North ◽  
The Irish Sea ◽  
Wind Driven Currents
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