Assessing suspended sediment dynamics in relation to ecological thresholds and sampling strategies in two Irish headwater catchments

Prediction of the impact of suspended sediment on aquatic ecosystems requires adequate knowledge of sediment dynamics in surface waters. Often, studies reporting the response of aquatic biota to suspended sediment are concerned with concentrations, while catchment erosion studies often report sediment delivery as annual loads and yields, making the comparison to documented ecological impacts difficult. Similarly, the European Union Freshwater Fish Directive (FFD) (78/659/EC) stipulates a guideline value of 25mgl which should not be exceeded, with the exception of floods and droughts. In this respect, the significance of suspended sediment in two Irish rivers was assessed using turbidity sensors calibrated for suspended sediment. Sediment yields of 0.07 tonnes (t) hayear and 0.44thayear and annual FFD exceedance frequency of 8.3% and 17.8% were estimated for the two catchments. Contrasts in the frequency of exceedance events between both catchments was observed, yet duration was typically short (

On Irish stickleback:Morphological diversification in a secondary contact zone

Question: How parallel is adaptive evolution when it occurs from different genetic backgrounds? Background: Divergent evolutionary lineages of several post-glacial fish species including the threespine stickleback are found together in Ireland. Goals: To investigate the morphological diversity of stickleback populations in Ireland and assess whether morphology evolved in parallel between evolutionary lineages. Methods: We sampled stickleback from lake, river, and coastal habitats across Ireland. Microsatellite and mitochondrial DNA data revealed evolutionary history. Geometric morphometrics and linear trait measurements characterized morphology. We used a multivariate approach to quantify parallel and non-parallel divergence within and between lineages. Results: Repeated evolution of similar morphologies in similar habitats occurred across Ireland, concordant with patterns observed elsewhere in the stickleback distribution. A strong pattern of habitat-specific morphology existed even among divergent lineages. Furthermore, a strong signal of shared morphological divergence occurred along a marine-freshwater axis. Evidently, deterministic natural selection played a more important role in driving freshwater adaptation than independent evolutionary history. © 2013 Mark Ravinet.

Consideration of future consequences and alcohol use among Northern Irish adolescents

This study investigated the relationship between consideration of future consequences and alcohol use among adolescents. A cross-sectional design was used and a large sample of 12-to 16-year-old schoolchildren (n = 806) in Northern Ireland were recruited for this study. Alcohol use was assessed using a composite measure of drinking behaviour, the Adolescent Alcohol Involvement Scale. Time perspective was measured using the Consideration of Future Consequences Scale (CFCS). Data were also gathered on self-esteem, three domains of self-efficacy and aggression, all of which have been found to be related to both drinking behaviour and time perspective. Factor analysis of the CFCS revealed support for a two-factor solution, with CFC-I representing present orientation and CFC-F representing future orientation. After controlling for year in school (proxy for age) and gender and for clustering at school level, scores on both subscales were significantly associated with alcohol use. Only CFC-F score remained significant with the addition of psychosocial variables. These results support recent findings of a significant relationship between CFCS score and alcohol use in UK adolescents and University undergraduates, and suggest that in more fully controlled analyses, future orientation, rather than present, is related to adolescent drinking. Results are discussed in relation to health promotion. © 2013 Informa UK Ltd.

Investigation of failures in Irish raised bogs

This paper presents the results of field geophysical testing and laboratory testing of peat from Carn Park and Roosky raised bogs in the Irish Midlands. The motivation for the work was highlight the importance of these areas and to begin to attempt to understand the reasons for the failure of the bogs despite them having surface slopes of some 1°. It was found that the peat is typical of that of Irish raised bogs being up to 8m thick towards the “high” dome of the bogs. The peat is characterised by low density, high water content, high organic content, low undrained shear strength and high compressibility. The peat is also relatively permeable at in situ stress. Geophysical electrical resistivity tomography and ground penetrating radar data shows a clear thinning of the peat in the area of the failures corresponding to a reduction in volume from dewatering by edge drains/peat harvesting. This finding is supported by detailed water content measurements. It was also shown that the peat base topography is relatively flat and indicates that the observed surface movement has come from within the peat rather than from the material below the peat. Potential causes of the failures include conventional slope instability, the effect of seepage forces or the release of built-up gas in the peat mass. Further measurements are required in order to study these in more detail.

Asynchrony between the Greenland ice core chronology and the radiocarbon calibration curve? Evidence from Irish bogs

A significant cold event, deduced from the Greenland ice cores, took place between 8200 and 8000 cal. BP. Modeling of the event suggests that higher northern latitudes would have also experienced considerable decreases in precipitation and that Ireland would have witnessed one of the greatest depressions. However, no well-dated proxy record exists from the British Isles to test the model results. Here we present independent evidence for a phase of major pine recruitment on Irish bogs at around 8150 cal. BP. Dendrochronological dating of subfossil trees from three sites reveal synchronicity in germination across the region, indicative of a regional forcing, and allows for high-precision radiocarbon based dating. The inner-rings of 40% of all samples from the north of Ireland dating to the period 8500-7500 cal. BP fall within a 25-yr window. The concurrent colonization of pine on peatland is interpreted as drier conditions in the region and provides the first substantive proxy data in support of a significant hydrological change in the north of Ireland accompanying the 8.2 ka event. The dating uncertainties associated with the Irish pine record and the Greenland Ice Core Chronology 2005 (GICC05) do not allow for any overlap between the two. Our results indicate that the discrepancy could be an artifact of dating inaccuracy, and support a similar claim by Lohne et al. (2013) for the Younger Dryas boundaries. If real, this asynchrony will most likely have affected interpretations of previous proxy alignments.

‘Blessed are the young, for they shall inherit the national debt’: Solidarity between generations in the Irish crisis

Ireland has gained a reputation for peaceable acceptance of austerity following a European Union/International Monetary Fund bailout in 2010. While proponents of austerity praise Ireland’s stoicism, critics of global capitalism argue that individuals and families are paying for mistakes made by elites. However, little is known about the strategies people adopt to cope with cutbacks to welfare entitlements. Drawing on a study of solidarity between generations living in Ireland in 2011–12, this article explores the lived experience of economic crisis and austerity. One hundred interviews with people of all ages and socio-economic backgrounds are analysed using constructivist grounded theory. Data show how austerity impacts differentially according to socio-economic status. While solidarity between generations leads to re-distribution of resources within families, providing some security for people with access to family resources, it reinforces inequality at societal level. We conclude that reliance on family promotes ‘coping’ rather than ‘protesting’ responses to austerity.

The Great Recession and the changing distribution of economic vulnerability by social class:The Irish case

Ireland provides an interesting case study of the distributional consequences of the Great Recession. To explore such effects we develop a measure of economic vulnerability based on a multidimensional risk profile for income poverty, material deprivation and economic stress. In the context of conflicting expectations of trends in social class differentials, we provide a comparison of pre and post-recession periods. Our analysis reveals a doubling of levels of economic vulnerability and a significant change in multidimensional profiles. Income poverty became less closely associated with material deprivation and economic stress and the degree of polarization between vulnerable and non-vulnerable classes was significantly reduced. Economic vulnerability is highly stratified by social class for both pre and post-recession periods. Focusing on absolute change, the main contrast is between the salariat and the non-agricultural self-employed and the remaining classes; providing some support for notions of polarization. In terms of relative change the higher salariat, the non-agricultural self-employed, the semi-unskilled manual and those who never worked gained relative to the remaining classes. This provides support the notion of ‘middle class squeeze’. The changing relationship between social class and household work intensity reflected a similar pattern. The impact of the latter on economic vulnerability declined sharply, while it came to play an increasing role in mediating the impact of membership of the non-agricultural middle classes. Responding to the political pressures likely to be associated with ‘middle class squeeze’ while sustaining the social welfare arrangements that have traditionally protected the economically vulnerable presents formidable challenges in terms of maintaining social cohesion and political legitimacy.