Southwest Ireland Research Articles

Crustal anisotropy in southwest Ireland from analysis of controlled source shear-wave data

Results from a travel-time analysis of three-component shear-wave (S-wave) data recorded in southwest Ireland during a controlled source seismic experiment have been used to investigate the magnitude of crustal anisotropy. The data used were recorded from 20 in-line shots on three-component short-period stations deployed at approximately 1-km spacing along two parallel profiles. Analysis of the travel-time differences between vertically and horizontally polarised S-waves recorded on vertical, radial and transverse seismometer components was undertaken using seismic phases travelling near the Earth's surface (S g) and reflected from the Moho (S mS). Travel-time differences between the components for both phases scatter largely within the range ± 0.2 s, which is about the uncertainty in the measurements, with no observed coherent variation with shot-receiver offset. Synthetic S-wave seismograms were also computed from 1-D S-wave velocity models with varying degrees of anisotropy in the upper and in the lower crusts. Travel-time differences of S g and S mS phases picked from these synthetic seismograms confirm that for anisotropies with probable symmetries of magnitude 1–2% in either the upper or lower crust should result in an observable variation of the travel-time differences between the transverse and radial, and transverse and vertical components with source–receiver offset. The study shows that crustal anisotropy does not contribute significantly to the marked anisotropy recently deduced from SKS and SKKS measurements in Ireland, which is therefore confirmed to reside at sub-crustal and deeper mantle levels.

An archaeology of southwest Ireland, 1570–1670. By Colin Breen. Pp 240, illus. Dublin: Four Courts Press. 2007. €45.

An archaeology of southwest Ireland, 1570–1670. By Colin Breen. Pp 240, illus. Dublin: Four Courts Press. 2007. €45.

Using mobile phone telemetry to investigate the haul-out behaviour of harbour seals Phoca vitulina vitulina

Information on the haul-out behaviour of pinnipeds is essential for increasing the accu- racy of population estimates necessary for the effective conservation of protected species, as well as improving survey design. The haul-out behaviour of 10 harbour seals Phoca vitulina L. in southwest Ireland was examined using a novel telemetry system based on global systems for mobile communi- cations technology. The data on the haul-out patterns of tagged individuals were examined using generalised additive modelling to determine potential factors of influence, such as the tide, the time of day and the time of year. The behaviour varied among seals, with time ashore reaching a maxi- mum during post-moult in October and decreasing to a minimum in February. A strong tidal in- fluence on haul-out behaviour was evident. Tagged seals hauled out more frequently at low tide. There was variation between individuals in the influence of time of day on haul-out behaviour. A cyclic pattern with lunar periodicity was evident in seals tagged in October, and the pattern varied between tidal periods. There was an overall large variation in patterns of behaviour over the tagging period, both between individuals and between tidal periods for each individual. This cautions against making inferences on the haul-out behaviour of the 'population' based on the behaviour of a small number of tagged individuals. The present study provides detailed information, heretofore unavail- able, on the haul-out behaviour of individual harbour seals and on the behaviour of the species in Ireland, and it has important implications for population assessment for conservation purposes across the species' entire geographical range.

European phylogeography of the common frog (Rana temporaria): routes of postglacial colonization into the British Isles, and evidence for an Irish glacial refugium

We use phylogenetic techniques to investigate the postglacial re-population of Europe by the common frog and, in particular, the colonization of Ireland. Three main hypotheses have been proposed for the re-establishment of the Irish fauna after the last ice age: arrival across a late-glacial land bridge from Britain; expansion from a glacial refuge in the south of Ireland and, for some species, re-introduction by humans from Iberia. We examined the phylogeographic structure of 52 populations of the common frog (Rana temporaria) throughout Europe using 476-bp mitochondrial cytochrome b gene sequences. Our data replicate earlier studies in showing substantial sequence divergence (3%) between Eastern and Western European common frog haplotypes. However, we uncover a new evidence that these haplotypes co-exist in Spain, Switzerland and France, and infer an expansion of the eastern clade along the Mediterranean coastal corridor. All the British samples fall within the Western European clade, but the Irish data imply a different history. Genetically distinct haplotypes occur in populations from the south-west of Ireland. This local genetic differentiation may be a consequence of a local glacial refuge, possibly combined with natural colonization or introduction from Western Europe.

Recent introduction or ancient ancestry? Use of genetic evidence to investigate the origins of range edge populations in natterjack toads (Bufo calamita)

The ability to distinguish between native and translocated populations is important in conservation biology, but can be problematic, especially near range edges. We describe here the use of variable genetic markers as an approach to resolving this issue. Natterjack toads Bufo calamita have a very restricted distribution in south-west Ireland. Populations in the main distribution area are well documented, but there are also some recently discovered ones at a widely separated site. We used genetic evidence to investigate whether the recently discovered populations are newly established or of ancient origin, using three criteria: genetic diversity, genetic structure and estimated time since divergence. The results highlighted some difficulties of using genetic data from range edge populations, where such issues are most likely to arise but where diversity (and thus statistical power) is often low. On balance the genetic data weakly supported the hypothesis that the newly discovered populations are not recent translocations. It will always be important in such investigations to use genetic inferences in combination with other independent lines of evidence (such as fossils) wherever possible.

Mycobacterium bovisStrains Causing Smear-Positive Human Tuberculosis, Southwest Ireland

Mycobacterium bovis caused 3% of human tuberculosis cases in southwest Ireland during 1998–2006. Of 11 M. bovis strains genotyped, 9 belonged to common animal spoligotypes. Seven strains were from sputum and potential sources of human-centered disease transmission. Ten-locus variable-number tandem repeat typing gave unique strain profiles and would detect disease outbreaks.

New dinoflagellate cysts from the Miocene of the Porcupine Basin, offshore Southwest Ireland

Four new dinoflagellate cyst species from the Lower and Middle Miocene strata of the Porcupine Basin, offshore southwest Ireland, are formally described. Batiacasphaera edwardsiae sp. nov. was previously described under open nomenclature from the Miocene of the adjacent Rockall Plateau. Lejeunecysta challengerensis sp. nov. is recorded sporadically from the Burdigalian and Serravallian. Selenopemphix porcupensis sp. nov. and Trinovantedinium henrietii sp. nov. are large‐sized dinoflagellate cysts with maximum dimensions of approximately 100 urn. Selenopemphix porcupensis sp. nov. is recorded in the uppermost Burdigalian and Langhian, and Trinovantedinium henrietii sp. nov. is present in the Langhian and lowermost Serravallian. Batiacasphaera edwardsiae sp. nov. is possibly biostratigraphically significant for the Middle Miocene.

Determining the cost of genital warts: a study from Ireland

Objectives: To determine the average cost of a case of genital warts, for both males and females, with a view to informing the current debate as to which Human papillomavirus...

CLIMATE AND RECRUITMENT OF ROCKY SHORE INTERTIDAL INVERTEBRATES IN THE EASTERN NORTH ATLANTIC

Studies of the impacts of climate and climate change on biological systems often attempt to correlate ecological responses with basin-scale indices such as the North Atlantic Oscillation (NAO). However, such correlations, while useful for detecting long-term trends, are unable to provide a mechanism linking the physical environment and ecological processes. Here we evaluate the effects of the NAO on recruitment variability of rocky intertidal invertebrates in the North Atlantic examining two possible climate-related pathways. Using a highly conservative test we interpret associations with the NAO integrated over a season (three months) as an indicator of atmospheric effects on newly settled recruits (NAO3), and the effects of the NAO integrated over six months (NAO6) as an indicator of changes in ocean circulation affecting patterns of larval transport. Through an extensive literature survey we found 13 time series, restricted to southwest Ireland and Britain and comprising five species, that could be used for statistical analysis. Significant correlations with NAO3, our proxy for atmospheric effects, were observed in the south-central domain of our study region (southwest Ireland and south England). Significant correlations with NAO6, the proxy for ocean circulation effects, were detected on southwest Ireland. The associations were detected for three (two barnacles and a topshell) at two sites. These results suggest that the NAO can have effects on the recruitment of intertidal invertebrates through different pathways linked to climate and be distributed heterogeneously in space. Based on previous evidence and the sign and geographic location of significant correlations, we suggest that winter NAO effects are likely to occur as a result of effects on the survival of early life stages settling during spring or through changes in phenology. Our results argue that a combination of modeling and synthesis can be used to generate hypotheses regarding the effects of climate on recruitment and aid in the design of field-based tests of explicit ecological mechanisms.

Well, water, rock: holy wells, mass rocks and reconciling identity in the republic of ireland

ABSTRACTThis paper explores the significance of holy wells and mass stones in Southwest Ireland, as expressions of competing narratives of meaning, identity, faith and history. Drawing on ethnographic interviews and participant observation, this essay argues that these places and the ritual activities that regularly occur there reflect and reconstruct contemporary Irish identities. In an era of rapid cultural change, these places comprise a tangible and experiential connection to Irish heritage and tradition. As reflected in interviews, conversations and published documents, these places are viewed as simultaneously embodying indigenous pre-Christian spiritualities as well as being locations of a distinctively Catholic faith. At the same time, they are important as secluded locations where Irish Catholic parishioners held mass during the colonial era of English oppression and as locations of popular religion, in contradistinction to orthodox Roman Catholicism. As such, holy wells and mass rocks demonstrate the ability of sacred places to integrate and reconcile complex and heterogeneous identities.

Participation in everyday activities and quality of life in pre-teenage children living with cerebral palsy in South West Ireland

BackgroundCerebral palsy (CP) is the most common cause of physical disability in children but its impact on quality of life is not well understood. This study examined participation in everyday activities among children without CP and children with mild, moderate and severe impairment due to CP. We then examined ten domains of quality of life in children with CP and investigated whether participation in everyday activities was associated with improved quality of life independent of gender, age and level of impairment.MethodsThis was a cross-sectional study of children aged 8–12 years based on two questionnaires, frequency of participation (FPQ) and KIDSCREEN, completed by parents of 98 children on the South of Ireland Cerebral Palsy Register (response rate = 82%) and parents of 448 children attending two Cork city schools (response rate = 69%) who completed one questionnaire (FPQ). Multiple linear regression was used: firstly to estimate the effect of severity of CP on participation in everyday activities independent of age and gender and secondly we estimated the effect of participation on quality of life independent of age gender and level of impairment.ResultsParticipation in 11 of the 14 everyday activities examined varied across the children without CP and the children with varying severity of CP. In general, increased impairment decreased participation. Independent of age and gender, there was a highly significant decrease in overall participation with a fall of -6.0 (95% CI = -6.9 to -5.2) with each increasing level of impairment. The children with CP generally had high quality of life. Increased impairment was associated with diminished quality of life in just two domains – Physical well-being and Social support and peers. Overall participation in everyday activities was significantly associated with quality of life in 3 of the 10 domains (Physical well-being, Social support and peers & Moods and emotions) in analysis adjusted for gender age and level of impairment.ConclusionWhile increased impairment due to CP restricts participation in the majority of everyday activities, the level of participation has a limited effect on the quality of life of the children with CP in age 8–12 years.

Constraints on crustal structure and composition within a continental suture zone in the Irish Caledonides from shear wave wide-angle reflection data and lower crustal xenoliths

SUMMARY Shear wave seismic velocities (Vs) when used together with compressional wave velocities (Vp) are a powerful diagnostic of the chemical composition and mineralogy of the continental lithosphere. In this paper, we present whole crustal models of Vs and Vp velocities from two wide-angle seismic profiles from southwest Ireland, which straddle the Eastern Avalonian Terrane within the Iapetus Suture Zone. These models are based on traveltime interpretations of primary and reflected P- and S-wave seismic phases generated by explosive underwater sources. The quality of the shear wave data is exceptional when compared to similar data sets recorded elsewhere and allows the distribution of Poisson's ratio (σ) within the entire crust to be accurately determined. Models of Poisson's ratio, Vp and Vs are then used to constrain crustal composition at various depths down to the Moho (ca. 32 km depth) using published laboratory velocity measurements from rocks of different metamorphic grades and chemistry. The results indicate that the Irish crust in this region of the Caledonian orogenic belt is unusually felsic in bulk composition with a σ value of 0.247, which is below the global average value of 0.265. Variations in σ within the upper ca. 5 km of crust are greatest (0.20–0.28) and can be correlated with siliciclastic and carbonate sediments in Devonian and Carboniferous extensional sedimentary basins that were formed during the early part of the Variscan orogenic cycle. The typically more uniform variation in the mid crust down to 15 km depth is consistent with a granite/granodiorite or metagreywacke composition of greenschist to amphibolite facies mineralogy. Within the lower crust the value of σ (0.257–0.265) is significantly less than the global mean value of 0.281 predicted from an average crustal petrology model. This suggests a bulk silica content (%SiO2) of ∼64 per cent for the lower crust, based on an empirical relationship between σ and %SiO2, determined from compilations of laboratory data. These results are consistent with petrophysical, geochemical and petrological data from an unusually well-preserved lower crustal xenolith suite from the Irish Midlands, hosted in early Carboniferous volcanic rocks. The xenoliths (mainly partially melted granulite facies metapelites) evidently represent the bulk composition of the lower crust, which was largely derived by accretion of sedimentary material, derived from oceanic, island arc and continental margin sources, during oblique Caledonian collision.

Vegetation and environmental variation in an Atlantic blanket bog in South-western Ireland

A vegetation survey was carried out in a relatively intact Atlantic blanket bog in Southwest Ireland to study the vegetation patterns in relation to environmental variation, and to quantify the effect of artificial and natural borders on compositional variation. The data were analysed using canonical correspondence analysis. In terms of both vegetation and water chemistry, the study site can be categorized as typical of Atlantic blanket bogs in the maritime regions of North-western Europe. The distribution of plant species was explained mainly by depth of the water table. The distribution of bryophytes was secondarily explained by the pH of the bog water, while the distribution of vascular plants was secondarily explained by concentrations of ammonia. The vegetation distribution exhibited little variation between the central sector of the peatland and its disturbed edges (hill-grazing and restoration areas), but a substantial variation was observed between the area along a natural edge (stream) and the areas close to the other peatland borders or centre. Similarly, the internal variation within each sector (centre, hill-grazing edge and restoration area edge) was small, but substantial vegetation variation was observed within the area located along the stream. The area along the stream was associated with relatively deep water table, shallow peat depth, high water colour, pH and NH4+ concentrations, and low Cl− concentrations in the bog water. Our results suggest the existence of strong centre-natural margin gradients, as in raised bogs, and indicate that human or animal disturbance do not give rise to the marked transition zones that often characterize natural margins of mire systems. This indicates that even small areas and remnants of Atlantic blanket bogs are worthy of conservation and that their conservation value would benefit from the inclusion of sectors close to the natural peatland borders, which would increase the plant biodiversity of the conserved area.

Sacoglossan gastropods on native and introduced hosts in Lough Hyne, Ireland: larval retention and population asynchrony?

The north-eastern Atlantic sacoglossan gastropod Elysia viridis was studied on littoral and sublittoral shores of the British Isles from 2001 to 2007 to evaluate its potential role in the known decline of the invasive green alga Codium fragile ssp. fragile. Across its European range, this sacoglossan associates with eight genera of algal hosts within three algal orders and two divisions; these hosts include native and introduced macroalgae. The ‘specialist’ herbivore was investigated primarily within the rocky shore community at Lough Hyne Marine Reserve, County Cork, south-west Ireland, with comparative information from surveys of 95 other sites in the British Isles. In Lough Hyne, E. viridis associated with the green algae Codium, Cladophora and Chaetomorpha as well as the red alga Griffithsia. The sacoglossan associated with Codium, Cladophora and Chaetomorpha as well as the red alga Halurus in Devon, Isle of Wight and the Channel Islands. Recruitment of E. viridis to Codium spp. in the lough was substantially higher than in most areas of the British Isles with 100% of the Codium hosts attacked during annual September surveys. The strong autumn pulse of sacoglossan recruitment, coupled with the asynchronous population dynamics compared to other shores, indicates retention of planktotrophic larvae within the lough. The previously reported decline in sacoglossan density with tidal level was hypothesized to be caused by sublittoral predators. Although our experiments failed to demonstrate an effect by large predators, the foraging of the abundant fingerling fish and small crabs could not be tested conclusively. Field experiments were consistent with the interpretation of intense sacoglossan herbivory in certain areas of the lough. However, even if the sacoglossans contribute to the local decline of C. fragile in the lough, they cannot account for the regional decline of the alga on the north-eastern Atlantic shores.

SMS seal: A new technique to measure haul-out behaviour in marine vertebrates

Many marine vertebrates, including pinnipeds, turtles and birds, spend periods of time ashore during their life cycles. Quantification of time spent ashore is important for estimating population parameters such as abundance and productivity in some species, but can prove to be a difficult task. Here we describe a novel telemetry system based on Global Systems for Mobile Communications (GSM), to provide detailed information on the haul-out behaviour of tagged animals. We tested the system on harbour seals in southwest Ireland. The GSM telemetry system proved an effective means of obtaining information on the haul-out activity of harbour seals in the study area and of providing crude movement information that was less labour intensive than VHF telemetry and provides an alternative means of data acquisition offering some advantages over satellite telemetry. The GSM tag with its internal antennae is more robust than a satellite tag. The GSM networks allow more information to be relayed, so the “cost per bit of data” is reduced. Moreover, the large global investment in GSM networks have resulted in a telemetry technology with low running costs and therefore with significantly lower costs of data acquisition via GSM relative to Argos systems. With the ever-expanding global GSM network coverage the system has significant potential applications in behavioural studies of amphibious vertebrates, such as estimating clutch frequency in sea turtles.

An archaeology of southwest Ireland, 1570-1670

An archaeology of southwest Ireland, 1570-1670

Rainfall distribution in a catchment in Southwest Ireland: implications for catchment modeling

Rainfall distribution in a catchment in Southwest Ireland: implications for catchment modeling

NEW DINOFLAGELLATE CYSTS FROM THE MIOCENE OF THE PORCUPINE BASIN, OFFSHORE SOUTHWEST IRELAND

Four new dinoflagellate cyst species from the Lower and Middle Miocene strata of the Porcupine Basin, offshore southwest Ireland, are formally described. Batiacasphaera edwardsiae sp. nov. was previously described under open nomenclature from the Miocene of the adjacent Rockall Plateau. Lejeunecysta challengerensis sp. nov. is recorded sporadically from the Burdigalian and Serravallian. Selenopemphix porcupensis sp. nov. and Trinovantedinium henrietii sp. nov. are large-sized dinoflagellate cysts with maximum dimensions of approximately 100 μm. Selenopemphix porcupensis sp. nov. is recorded in the uppermost Burdigalian and Langhian, and Trinovantedinium henrietii sp. nov. is present in the Langhian and lowermost Serravallian. Batiacasphaera edwardsiae sp. nov. is possibly biostratigraphically significant for the Middle Miocene.

Till sedimentology and stratigraphy on the Dingle Peninsula, SW Ireland: implications for Late Quaternary regional ice flow patterns

Investigation of Late Quaternary glacigenic sediments exposed in coastal sections on the Dingle Peninsula, southwest Ireland shows that during the last glaciation, an advance of local ice occurred across the western and northern coasts of the peninsula and deposited a series of subglacial tills. These tills were formed largely by the subglacial reworking of underlying parent material. Sedimentological contrasts between them reflect variations in the nature of the parent material from which the tills were derived, as well as variations in the magnitude of strain during till formation. The local ice reworked pre-existing glacial deposits associated with an earlier advance of regional ice from the north. Evidence for this earlier advance of regional ice is provided by erratics of Galway Granite contained within the tills at some sites. No in-situ deposits associated with the granite-carrying ice were observed on the peninsula. Clast macrofabric and provenance data indicate that all of the tills recorded are the product of the radial flow of local ice coastwards from the peninsula.

The ecology of sponges in Lough Hyne Marine Nature Reserve (south-west Ireland): past, present and future perspectives

Lough Hyne was Europe's first Marine Nature Reserve and is a well known biodiversity hotspot that supports extensive sponge assemblages. The unusual, but predictable, flow and sedimentation regimes have important impacts on the sponge assemblages at the species and assemblage levels. Here I present a review of recent sponge research at Lough Hyne, which covers: (1) a description of the sponge-dominated habitats; (2) the biological and physical factors controlling sponge biodiversity and abundance; (3) sponge species and assemblage level morphological variability; and (4) the relationship between sponge morphological, species and functional diversity. It appears that physical factors are primarily responsible for the sponge diversity and abundance patterns found in Lough Hyne, although the importance of intra- and interphyletic (particularly with algae) competitive interactions requires further investigation. Although our knowledge of how sponges respond and adapt to environmental variability has increased substantially because of the research conducted at Lough Hyne, I have highlighted a number of future research areas in the context of Lough Hyne sponge assemblages, which are relevant to understanding structuring processes across the globe.