Small-scale variation within a Modiolus modiolus (Mollusca: Bivalvia) reef in the Irish Sea. III. Crevice, sediment infauna and epifauna from targeted cores

2008 ◽  
Vol 88 (1) ◽  
pp. 151-156 ◽  
Author(s):  
E.I.S. Rees ◽  
W.G. Sanderson ◽  
A.S.Y. Mackie ◽  
R.H.F. Holt
Keyword(s):  
Organic Matter ◽  
Species Richness ◽  
Irish Sea ◽  
Small Scale ◽  
Faecal Pellets ◽  
North West ◽  
Modiolus Modiolus ◽  
Suction Sampler ◽  
The Irish Sea ◽  
Complex Habitat

Beds of Modiolus modiolus, in areas of moderate to strong tidal currents, develop into reefs with a relief of wave like undulations 0.09–0.45 m in amplitude and length scales of 6–18 m. Cores taken by diver operated suction sampler were targeted at positions on the ridges and troughs of a reef, in the Irish Sea off north-west Wales, allowing the fauna to be compared between adjoining ridges and troughs. Sessile epifauna was mostly attached to the larger mussels clumped together on the ridges. The crevice fauna and infauna were also nearly three times more abundant on the ridges, but the lists of species were similar from the two sub-habitats. Species richness was higher on the ridges, however, diversity and evenness measures were similar for ridges and trough samples. The Modiolus sub-habitats were found to be distinct from other macrofaunal assemblages in the wider southern Irish Sea. Deposition of faecal pellets in the spatially complex habitat amongst the mussels provided conditions suitable for an infauna more typical of inshore muddy sands enriched by organic matter. The scale of the ridge and trough morphology may increase variability between replicates when grabs are used remotely to sample this type of biogenic feature.

Small-scale variation within a Modiolus modiolus (Mollusca: Bivalvia) reef in the Irish Sea. II. Epifauna recorded by divers and cameras

2008 ◽  
Vol 88 (1) ◽  
pp. 143-149 ◽  
Author(s):  
W.G. Sanderson ◽  
R.H.F. Holt ◽  
L. Kay ◽  
K. Ramsay ◽  
J. Perrins ◽  
...  
Keyword(s):  
Irish Sea ◽  
Small Scale ◽  
Competitive Response ◽  
North West ◽  
The North ◽  
Strangford Lough ◽  
Modiolus Modiolus ◽  
Bed Form ◽  
The Irish Sea ◽  
Horse Mussel

The spatial heterogeneity of epifauna on a Modiolus modiolus reef off north-west Wales was investigated using divers. The community associated with these horse mussels was similar to that described previously from Loch Creran and the north basin of Strangford Lough. Some differences in epifauna may be attributable to the less sheltered nature of the site. Modiolus modiolus numbers and the associated epifaunal community were significantly different between ridge and trough sub-habitats. Troughs can be considered ‘reduced’ ridge communities whereas ridges have high densities of horse mussels and certain sessile taxa were correlated with their abundance. Modiolus modiolus aggregation as a competitive response to the feeding environment, enhanced food availability on ridges and sediment deposition amongst mussel clumps may start to explain the undulating bed-form. Patchiness in community composition and periodic cover by ophuroids has implications when considering the monitoring of the horse mussel community. Stratified, in situ recording of the highly populated ridges could improve the statistical sensitivity of monitoring horse mussel reefs whilst simultaneously focusing on the more sensitive indicators of fishing threats.

Small-scale variation within a Modiolus modiolus (Mollusca: Bivalvia) reef in the Irish Sea: I. Seabed mapping and reef morphology

2008 ◽  
Vol 88 (1) ◽  
pp. 133-141 ◽  
Author(s):  
C. Lindenbaum ◽  
J.D. Bennell ◽  
E.I.S. Rees ◽  
D. McClean ◽  
W. Cook ◽  
...  
Keyword(s):  
Irish Sea ◽  
Small Scale ◽  
Acoustic Characteristics ◽  
Side Scan Sonar ◽  
Multibeam Echosounder ◽  
North West ◽  
Modiolus Modiolus ◽  
Distinctive Morphology ◽  
Seabed Mapping ◽  
The Irish Sea

Surveys by digital side-scan sonar, RoxAnnTM acoustic ground discrimination systems, multibeam echosounder and a sub-bottom profiling system showed that a Modiolus modiolus reef, in the Irish Sea off Pen Llŷn, north-west Wales, had a distinctive morphology and acoustic characteristics. The extent of the reef could therefore be determined and the benthic structure reliably mapped. The biogenic reef is in an area with moderately strong tidal currents and overlays lag gravel and cobbles with patchy sand veneers. The mussels form an undulating surface, orientated perpendicular to the current, with an average wavelength of 11.7 m and amplitude of 0.24 m that is significantly different from the surrounding seabed. Reef deposits reach a thickness of 1 m on top of the underlying lag gravels. The characteristic reef surface morphology helps distinguish the reef from the surrounding seabed on side-scan sonar and multibeam echosounder records and the undulations create the spatial complexity that influences the small-scale distribution of the associated epifauna, and infauna, reported in papers II and III of this series. The M. modiolus reef was recorded in the same location 40 y ago and has probably persisted there for over 150 y. Monitoring implications are discussed.

The Spread of Elminius Modestus Darwin In North-West Europe

1958 ◽  
Vol 37 (2) ◽  
pp. 483-520 ◽  
Author(s):  
D. J. Crisp
Keyword(s):  
East Coast ◽  
Irish Sea ◽  
North Coast ◽  
Long Distance ◽  
North West ◽  
The North ◽  
Competition For Space ◽  
South East England ◽  
The Irish Sea ◽  
Balanus Balanoides

Material collected prior to 1940 indicates that Elminius modestus was not present on British coasts at that time.Elminius increased in abundance in south-east England from 1946 to 1950 and extended its range as far as the Humber, where it halted.Its advance westwards along the south coast was similarly halted at Portland, but by 1948 independent colonies had been established in several of the river systems of Devon and Cornwall, in Milford Haven, and in the Bristol Channel.The first populations in the Irish Sea were in Morecambe Bay. From there Elminius spread rapidly south and west along the north coast of Wales, and more slowly north and west towards Galloway, eventually bridging the sea to the Isle of Man.Detailed observations showed that Elminius advanced along the uniformly favourable north coast of Wales as a definite front moving at a rate of approximately 20–30 km per year. Around Anglesey where tidal currents were stronger it appeared simultaneously in many scattered centres.A distinction is drawn between marginal dispersal taking place under the influence of normal agencies at the boundary of an existing population, and remote dispersal due to an artificial or freak transport over a long distance. In the case of Elminius the maximum distance that is likely to be bridged by marginal dispersal in the absence of strong residual drifts is about 30 miles.Elminius probably first appeared near Southampton, and was introduced into the Thames estuary area probably by remote dispersal. Thence it spread along the east coast and was transported to Holland. Its extension into south Devon, the Bristol Channel, the Irish Sea, and to the French coast must also be attributed to remote dispersal.The main ecological effects of Elminius result from competition for space with Balanus balanoides. Since Elminius breeds in summer, its dominance has a profound effect on the composition of the summer plankton, greatly increasing the number of barnacle nauplii, presumably at the expense of other larvae.

Some observations on the distribution of heavy metals in Sullom Voe

1981 ◽  
Vol 80 ◽  
pp. 101-111
Author(s):  
P. Coackley ◽  
D. H. Bache ◽  
P. G. Smith
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Irish Sea ◽  
Sediment Composition ◽  
Sediment Samples ◽  
Modiolus Modiolus ◽  
The Irish Sea ◽  
Copper Lead

SynopsisData is presented to provide a baseline for assessing heavy metal pollution in Sullom Voe.Procedures are described for the measurement of concentrations of zinc, chromium, copper, lead, cadmium and nickel in sediment samples and in specimens of Modiolus modiolus (L.).Analysis showed that the concentration values in Modiolus were similar to those measured in specimens obtained from the Irish Sea.In the sediment samples, it appeared that the distribution of metals was independent of the concentration and type of metal. The distribution of the metals which were analysed also showed significant dependence on the sediment composition.

scholarly journals Connectivity and Dispersal Patterns of Protected Biogenic Reefs: Implications for the Conservation of Modiolus modiolus (L.) in the Irish Sea

PLoS ONE ◽  
2015 ◽  
Vol 10 (12) ◽  
pp. e0143337 ◽  
Author(s):  
Kate Gormley ◽  
Clara Mackenzie ◽  
Peter Robins ◽  
Ilaria Coscia ◽  
Andrew Cassidy ◽  
...  
Keyword(s):  
Irish Sea ◽  
Dispersal Patterns ◽  
Modiolus Modiolus ◽  
The Irish Sea

scholarly journals Towards Winter Seasonal Predictability of the North West European Shelf Seas

2021 ◽  
Vol 8 ◽  
Author(s):  
Jonathan Tinker ◽  
Leon Hermanson
Keyword(s):  
North Sea ◽  
Irish Sea ◽  
Seasonal Forecasts ◽  
North West ◽  
Southern North Sea ◽  
The North ◽  
Predictive Skill ◽  
European Shelf ◽  
Shelf Seas ◽  
The Irish Sea

We investigate the winter predictability of the North West European shelf seas (NWS), using the Met Office seasonal forecasting system GloSea5 and the Copernicus NWS reanalysis. We assess GloSea5’s representation of NWS climatological winter and its skill at forecasting winter conditions on the NWS. We quantify NWS winter persistence and compare this to the forecast skill. GloSea5 simulates the winter climatology adequately. We find important errors in the residual circulation (particularly in the Irish Sea) that introduce temperature and salinity biases in the Irish Sea, English Channel, and southern North Sea. The GloSea5 winter skill is significant for SST across most of the NWS but is lower in the southern North Sea. Salinity skill is not significant in the regions affected by the circulation errors. There is considerable NWS winter temperature and salinity persistence. GloSea5 exhibits significant predictive skill above this over ∼20% of the NWS, but for most of the NWS this is not the case. Dynamical downscaling is one method to improve the GloSea5 simulation of the NWS and its circulation, which may reduce biases and increase predictive skill. We investigate this approach with a pair of case studies, comparing the winters of 2010/2011 and 2011/2012 (with contrasting temperature and salinity anomalies, and NAO state). While 2 years are insufficient to assess skill, the differences in the simulations are evaluated, and their implications for the NWS winter predictability are considered. The NWS circulation is improved (where it was poor in the GloSea5), allowing more realistic advective pathways for salinity (and temperature) and enhancing their climatological spatial distributions. However, as the GloSea5 SST anomaly is already well simulated, downscaling does not substantially improve this – in other seasons or for other variables, downscaling may add more value. We show that persistence of early winter values provides some predictive skill for the NWS winter SST, and that the GloSea5 system adds modestly to this skill in certain regions. Such information will allow prospective end-users to consider how seasonal forecasts might be useful for their sector, providing the foundation on which marine environmental seasonal forecasts service and community may be developed for the NWS.

The occurrence of Norway lobster (Nephrops norvegicus) larvae off the Portuguese coast

2005 ◽  
Vol 85 (4) ◽  
pp. 937-941 ◽  
Author(s):  
Antonina dos Santos ◽  
Álvaro Peliz
Keyword(s):  
Production Method ◽  
Irish Sea ◽  
Biomass Estimation ◽  
Nephrops Norvegicus ◽  
North West ◽  
Portuguese Coast ◽  
The North ◽  
Norway Lobster ◽  
South West Coast ◽  
The Irish Sea

Norway lobster (Nephrops norvegicus) larvae have been investigated in northern European waters, particularly in the Irish Sea where biomass estimation studies are used for the annual larval production method. However, nothing is known of their distribution in southern European waters, off the Portuguese coast or in the Mediterranean Sea. From zooplankton sampling off the Portuguese coast between October 1986 and March 2001, planktonic larvae of this species were known to occur from January to April off the north-west and south coasts. In the north, larvae were only observed over the shelf, shoreward of the upper limit of the adults' distribution. Larvae were never collected off the south-west coast of Portugal, even though this is one of the largest fishing grounds for this species off the Iberian Peninsula. The absence of larvae from all surveys in this region may relate to the local oceanographic conditions and shelf width.

V.—Glacial Geology: Old and New

1892 ◽  
Vol 9 (7) ◽  
pp. 310-321
Author(s):  
T. Mellard
Keyword(s):  
West Coast ◽  
East Coast ◽  
Irish Sea ◽  
Glacial Geology ◽  
The South ◽  
North West ◽  
The North ◽  
The Subject ◽  
The Irish Sea ◽  
River Valleys

Over twenty years ago I commenced the study of the glacial deposits of the neighbourhood of Liverpool, and as the observations grew they came to embrace a considerable share of the drainagebasin of the Irish Sea.I have personally inspected and kept full records of all of the important artificial excavations likely to throw light upon the subject, in addition to examining and making sections of the natural exposures of glacial drift which abound on the north-west coast of England, the coast of Wales, and in the river valleys draining into the Irish Sea, and to a lesser extent the drift on the east-coast of Ireland and the south of Scotland.

The Portencorkrie Complex of Wigtownshire

1943 ◽  
Vol 80 (5) ◽  
pp. 171-195 ◽  
Author(s):  
Norman Holgate
Keyword(s):  
Geological Survey ◽  
Irish Sea ◽  
Ordnance Survey ◽  
Igneous Complex ◽  
North West ◽  
The North ◽  
Plutonic Rocks ◽  
The Irish Sea ◽  
North And South

The Portencorkrie igneous complex, a trapezoidal area of plutonic rocks intrusive into Silurian sediments, is situated in the Rhinns district of Wigtownshire some sixteen miles south of Stranraer and about four miles north-west of the Mull of Galloway. It appears on the Geological Survey (Scotland) 1-inch Sheet 1, and lies within the Ordnance Survey 6-inch quarter-sheets Wigtownshire 33 S.W. and 37 N.W. To the north and south the igneous margin can be followed with fair accuracy, while to the east the boundary is obscured by drift. Westwards, the rocks pass beneath the Irish Sea.

scholarly journals The Mesolithic Footprints Retained in One Bed of the Former Saltmarshes at Formby Point, Sefton Coast, North West England

2021 ◽  
pp. 295-315
Author(s):  
Alison Burns
Keyword(s):  
Temporal Relationship ◽  
Dynamic Environment ◽  
The Other ◽  
Irish Sea ◽  
Embodied Knowledge ◽  
Intertidal Zones ◽  
North West ◽  
Animal Activity ◽  
The Irish Sea ◽  
Coastal Land

AbstractIn the early Holocene period, extensive tracts of coastal land were submerged as the climate warmed and meltwaters flooded into the oceans. As the Irish Sea expanded, coastlines altered and large intertidal zones were created as tracts of low-lying land at the tidal margins were gradually submerged. In these areas, reed swamp and saltmarsh formed which, too, were inundated for varying periods of time. However, in the calmer warmer weather of the late spring and summer, birds and mammals were drawn on to the mudflats where they could feed on molluscs, or new reed and sedge shoots, wallow in the cooling mud, drink the brackish water or, for some predators, hunt. The behavioural tendencies of some species are revealed by their footprints which show their engagement within this environment – some breeds moved on to the marshes while others moved away. The humans who shared this landscape understood the opportunities offered by these predictable behaviours. Their trails run along and across those left by many species, leaving a visible network of human and animal activity preserved in the hardened mud. These will be described through an examination of the footprints recorded in three contexts which formed the stratigraphy of a Mesolithic bed at Formby Point in North West England. The persistent return to the mudflats by generations of people reflects an embodied knowledge of this coastal landscape, learnt in childhood and practiced in adulthood. The ability to modify movements in the landscape, to respond to the daily tides, the changing seasons and a fluctuating environment, all suggest a spatial-temporal relationship which not only encompassed a dynamic environment but also the other life that dwelt within it.

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