Southeast Ireland Research Articles

A new species of Grania (Enchytraeidae, Clitellata, Annelida) and redescription of Grania pusilla from a rocky shore in SE Ireland

Two species of marine Enchytraeidae belonging to the genus Grania Southern, 1913, Grania mira sp.nov and Grania pusilla Erséus, 1974, are described from the rocky shores of southeast Ireland. Grania mira has distinctive muscular modifications of the male ducts. Grania pusilla which was previously reported only from the coasts of Norway and Sweden by Erséus (1974), is completely redescribed, including information on many additional morphological characters noted from recent taxonomic literature on Grania. It is reinstated to the level of species. The species has a penial stylet and a large glandular penial bulb. Differences in setal distribution between specimens of G. pusilla from Ireland and those from Norwegian and Swedish populations are attributed to geographical separation limiting genetic exchange. This is the first report of Grania in Ireland since Southern's discovery of Grania maricola in 1913. Grania maricola shares a structurally simple penial bulb type with G. pusilla, but the species differ in spermathecal shape, spermathecal ectal pore position and vas deferens length.

Water movement in a structured soil in the south-east of Ireland: preliminary evidence for preferential flow

A study was carried out on a structured soil in the south-east of Ireland to investigate How patterns of water in soil. Dissolved Acid Red dye was allowed infiltrate the soil from the surface. Thereafter the dyed soil profiles were exposed and the pattern of movement of the dye was recorded. Infiltration measurements, under tension, were also undertaken on the same soil at several soil depths and these were compared with tensionless infiltration. The results provided preliminary evidence for preferential How in the soil. Nitrate leaching data, from a grazing study, tended to confirm the results. The importance of preferential How with regard to movement of manures and chemicals towards groundwater. which will depend on the timing of the application of those substances and the occurrence of significant rainfall events is discussed. Soils having physical characteristics conducive to preferential flow are illustrated.

Acid mine drainage composition and the implications for its impact on lotic systems

Intensive sampling of acid mine drainage from adits draining the abandoned copper and sulphur mines at Avoca, south-east Ireland, has confirmed a seasonal variation in the Zn:Cu ratio observed previously. The variation in the Zn:Cu ratio leads to extreme variations in the toxicity of the drainage, and linked with increased adit flows and surface runoff during wetter months, often results in higher river toxicity, even during high river discharge rates. This seasonal variation in toxicity has important ramifications for the control of AMD to surface waters. Sampling over a three-year period shows that the rate of discharge from the adits follows a seasonal cycle being high in the spring, declining through summer to reach lowest flows in autumn and rising again in the winter. During the intensive sampling study over a 13-month period, the discharge rate in the Deep Adit varied from 8.5 to 37.3 l/s compared to 6.3 to 35.2 l/s in the Ballymurtagh Adit. This represents a total discharge rate for the two adits of between 1265 and 6270 m 3/d. Significant weights of cations were discharged from the two adits, ranging from 169–1279 kg/d for Fe, 69–459 kg/d for Zn, 1.5–34.7 kg/d for Cu, and 0.167–0.875 kg/d for Cd, with the Deep Adit contributing on average 40.4, 70.4, 66.7 and 80.9% of each metal respectively over the sampling period of 13 months. The impact of AMD on the river biota is severe with a major decrease in the number of taxa and faunal abundance. The species deficit at all sites below the mines is in excess of 87%. Dipterans dominate impacted sites with Chironomidae abundant. Fish are eliminated except for juvenile eels close to the estuary.

Influence of seed rate and sowing date on the yield and grain quality of Blenheim spring malting barley in the south-east of Ireland

The effect of four seed rates on the grain yield, grain N content and grain size of Blenheim malting barley sown on two dates in the spring was tested on three different soils over a 4-year period (1991–94). The four seed rates (120, 160, 200 and 240 kg/ha) gave mean plant populations of 222, 308, 374 and 430 plants/m2, respectively, for the first sowing date (February to early March) and 235, 340, 405 and 470 plants/m2 for the second sowing date, 3–5 weeks later (late March to mid-April). The earlier-sown crops generally gave greater yield, lower grain N and smaller amount of screenings, but in two of the twelve experiments, the first sowing gave lower yield and greater grain N.The influence of seed rate on yield and quality depended on sowing date. The three higher seed rates (160, 200, 240 kg/ha) had little influence on yield or grain N, irrespective of sowing date, and there was no significant difference in yield between the lowest (120 kg/ha) and the three higher seed rates when the crop was sown in February and early March. But when the crops were sown in April, the lowest seed rate (120 kg/ha) gave the lowest yield in all seven comparisons and gave significantly reduced yield in three of the seven comparisons. There was a significant increase in grain N in three of the comparisons. Seed rate had little effect on grain screenings or 1000-grain weight. Soil differences did not influence the effect of seed rate on the yield and quality of the grain.

A time-concentration study on the effects of ozone on spring wheat ( Triticum aestivumL.). : 3: Effects on leaf area and flag leaf senescence

Spring sown wheat ( Triticum aestivum L. cv. `Promessa') was exposed to different concentrations of ozone in open-top chambers over a three year period at a site in the south-east of Ireland. Filtered and non-filtered treatments were used in addition to fumigated treatments in which additional ozone was added to the non-filtered air. Ozone was added either as short term high concentration exposures or as long term low concentration exposures. In 1991, exposure to the A+50 (Ambient+50 ppb ozone) treatment resulted in a substantial reduction in the green leaf area index and enhanced both the onset and the rate of leaf yellowing. The A+50 treatment in 1993 also resulted in a reduction in green leaf area in addition to accelerating chlorophyll and soluble protein loss in flag leaves. This treatment caused a more gradual loss of chlorophyll and green leaf area in comparison to the same treatment in 1991 which received a greater amount of potentially damaging ozone. In contrast the A+25 treatment in 1992 delayed leaf yellowing and enhanced green leaf retention in comparison to the filtered control treatment. This treatment received the same total cumulative ozone exposure as the A+50 treatment in 1991 but was supplied as a lower concentration over a longer time interval. High concentrations applied over short time intervals proved more phytotoxic than identical exposures in which lower concentrations were applied over longer time intervals. Changes in leaf senescence and in leaf area index induced by ozone were closely paralleled by changes in the grain yield. The results suggest that changes in grain yield are the result of ozone induced alterations in leaf senescence which lead to changes in the leaf area available for photosynthate production.

Evaluation of the rehabilitation procedure of a pyritic mine tailings pond in Avoca, Southeast Ireland

A 32 ha tailings pond used for the disposal of pyritic mine waste was examined after a period of eight years to determine the success of the rehabilitation plan used to revegetate the site. This was achieved by examining both the vegetation cover and the quality of the topsoil in order to determine the effect of the tailings. A number of floristic habitats were identified within the site indicating that succession had occurred since revegetation of the area with metal-tolerant grass species. Four main habitats were investigated: leguminous, grass, gorse and low canopy. The soil layer in Shelton Abbey was 25–30 cm deep and contained levels of nutrients and metals comparable to those found in unpolluted soils. It was followed by a 20–25 cm layer of mixed soil and tailings, followed by the tailings only. The tailings retained elevated concentrations of metals indicating their unsuitability for growth of unadapted plant species. Vegetation from all habitats, analysed both in the summer and winter, contained higher levels of iron only compared with vegetation grown on unpolluted soils. Metals do not appear to be significantly leached from the tailings either into the soil or into surface and ground waters, and have not been accumulated to above normal levels by plant uptake. The rehabilitation protocol used at the site appears to have been successful. However, the site needs to be managed on an on-going basis to ensure the integrity of the bund and revegetated area. © 1998 John Wiley & Sons, Ltd.

Environmental impact and remediation of acid mine drainage: a management problem

Work carried out at the abandoned copper (Cu) and sulphur (S) mine at Avoca (south east Ireland) has shown acid mine drainage (AMD) to be a multi-factor pollutant. It affects aquatic ecosystems by a number of direct and indirect pathways. Major impact areas are rivers, lakes, estuaries and coastal waters, although AMD affects different aquatic ecosystems in different ways. Due to its complexity, the impact of AMD is difficult to quantify and predict, especially in riverine systems. Pollutional effects of AMD are complex but can be categorized as (a) metal toxicity, (b) sedimentation processes, (c) acidity, and (d) salinization. Remediation of such impacts requires a systems management approach which is outlined. A number of working procedures which have been developed to characterise AMD sites, to produce surface water quality management plans, and to remediate mine sites and AMD are all discussed.

Metal contamination of riverine sediments below the Avoca mines, south east Ireland

The River Avoca is severely polluted by discharges of acid mine drainage (AMD) from the abandoned sulphur and copper mines at Avoca. The riverine sediments were studied during a low flow period to establish the degree of contamination and to identify the major processes affecting sediment metal concentrations. pH plays a major role in the regulation of zinc adsorption and desorption in sediments, showing a significant correlation (p&0.001). The zinc concentration in the sediment falls below background levels after the input of AMD. However, the metal precipitated when the pH increased downstream of a fertiliser factory (pH≫8.0), some 7 km below the mine. In contrast Cu and Fe significantly increased (p≫0.001) both in the sediment (0--30 mm depth) and the surface ochre immediately below the mixing zone. Copper removal appears to be primarily by co-precipitation. Higher sediment enrichment factors for all metals were obtained in the surface sediment layer (ochre) deposited on larger stones and in floc material collected in sediment traps, compared with the subsurface sediment. Cadmium was not recorded in any of the sediment collected at the detection limit used (0.01 μg g-1). Metal deposition in the sediments was found to be spacially variable, so sub-sampling is required, although replicates show little variation. Results indicate that short term variation in metal inputs is identified by sampling the surface layer only, whereas sampling of the subsurface layer (<63 μm fraction) is more suitable for identifying long-term trends in sediment quality. The implication of sediment analysis in assessing environmental impact is discussed.

Effects of Depth Phases of the Clonroche Soil Series and Farming Skill on Spring Barley Yields

This study was carried out in the south-east of Ireland (Co. Wexford) over a four-year period (1984-7) to determine the factors responsible for the variation in yield of spring barley obtained by growers whose farms were situated on the Clonroche Soils Series. The results show that the level of management skills had a significant effect (P<0.00l Jon yield variance in all four years. The mean difference in yield over the four-year period between the most skilled growers (Class 1) and the least skilled growers (Class 3) was 1.13 t/ha. Soil depth differences within the Clonroche Series gave significant difference (P<0.001) in yield only in 1984. when the soil moisture stress was sufficiently great to expose the difference in moisture-holding capacities of the three depth phases within the Series. Key Index Words: Clonroche Soils Series, yields, management skills.

The distribution of Oligochaeta on an exposed rocky shore in southeast Ireland

The distribution of Oligochaeta on an exposed rocky shore in southeast Ireland

Metal contamination from open‐cast copper and sulphur mining in southeast Ireland

The metal content was determined in soil and vegetation around the eastern zone of the disused sulphur and copper mines at Avoca (southeast Ireland). A 250 m × 250 m grid survey was conducted covering a total area of 4 km2. The mining belt was in the centre of the investigated site and was sampled separately. Iron, Zn, Cu and Cd concentrations in soil and plant material were determined, in addition to soil organic matter content and soil pH. Soil samples taken from the spoil showed elevated Cu and Cd concentrations, and low soil pH and organic matter content. At least 50 per cent of the agricultural sites examined around the East Avoca Mine showed elevated soil Cu and Cd concentrations, whereas Zn and Fe soil concentrations were within the range for unpolluted soils. None of the vegetation analysed had elevated Zn, Cd, Fe or Cu concentrations. Overall there was no indication of serious metal contamination in either soils or vegetation surrounding the mine in spite of extensive dust deposition during open-pit mining activity 15–30 years ago. However, a plume of elevated Cu in the soil was identified, which originated from a large spoil heap and had been spread for some 2·0 km by the prevailing wind.

Metal contamination from open-cast copper and sulphur mining in southeast Ireland

Metal contamination from open-cast copper and sulphur mining in southeast Ireland

A time-concentration study on the effects of ozone on spring wheat ( Triticum aestivum L.). 1. Effects on yield

Spring-sown wheat ( Triticum aestivum L., cv. ‘Promessa’) was grown in open-top chambers and ambient-air plots at a site in the southeast of Ireland, and exposed to different concentrations of ozone in a 3-year study carried out from 1991 to 1993. The treatments used in the study were charcoal-filtered air, non-filtered air and non-filtered air to which extra ozone was added. Additional ozone was added to the treatments either as short-term high-concentration exposures or as long-term low-concentration exposures. Air filtration had no significant effect on grain yield, indicating that ambient levels of ozone over the experimental period in the study area did not have the potential to decrease the yield of spring wheat crops. Additional ozone exposures with higher peak concentrations had the most detrimental effect on grain yield. Short-term fumigation with ambient ozone plus 50 parts per billion (p.p.b.) in 1991 resulted in a 53% reduction in grain yield. In 1992 a similar cumulative exposure but with ambient ozone plus 25 p.p.b. applied over a longer time interval increased grain yield by 17%. In 1993 these observations were confirmed when an ozone exposure with higher peak concentrations significantly reduced grain yield, while an identical exposure with lower peak concentrations had no effect. Changes in grain yield were primarily the result of changes in grain filling. They were accompanied by changes in protein percentage as well as in the percentage of small, improperly filled grains. The results suggest that increased emphasis should be given to peak concentrations in the assessment of ozone effects on vegetation.

Seasonal variation of metal contamination of riverine sediments below a copper and sulphur mine in South-East Ireland

The discharge of acid mine drainage (AMD) from the abandoned sulphur and copper mines at Avoca (S.E. Ireland) results in the formation of ochreous deposits on the river substrate. Sediment sampling was carried out intensively during June and August, 1994 and again during March and April, 1995 to investigate seasonal variation of Fe, Cu and Zn concentration in riverine sediments of the receiving water (Avoca River). Temporal and spatial variations indicate that, apart from pH, hydrological factors play a major role in metal accumulation of highly energetic river systems. Zinc adsorption and desorption of “ochre” is chiefly regulated by pH, while Cu removal seems to be primarily by co-precipitation with iron. Basic considerations with regard to sampling techniques are discussed.

Seasonal variation of metal contamination of riverine sediments below a copper and sulphur mine in South-east Ireland

The discharge of acid mine drainage (AMD) from the abandoned sulphur and copper mines at Avoca (S.E. Ireland) results in the formation of ochreous deposits on the river substrate. Sediment sampling was carried out intensively during June and August, 1994 and again during March and April, 1995 to investigate seasonal variation of Fe, Cu and Zn concentration in riverine sediments of the receiving water (Avoca River). Temporal and spatial variations indicate that, apart from pH, hydrological factors play a major role in metal accumulation of highly energetic river systems. Zinc adsorption and desorption of ‘ochre’ is chiefly regulated by pH, while Cu removal seems to be primarily by co-precipitation with iron. Basic considerations with regard to sampling techniques are discussed.

Comparison of early, normal and late sowing at three rates of nitrogen on the yield, grain nitrogen and screenings content of Blenheim spring malting barley in Ireland

SUMMARYNine experiments were carried out on three different soil types in the south-east of Ireland over three years (1989, 1992 and 1993) to test the effect of early, normal and late sowing at three rates of fertilizer nitrogen (100, 125, 150 kg/ha) on the yield and grain quality ex-farm of spring malting barley (cv. Blenheim). Early sowing (January or February) was not possible in 1990 and 1991 due to wet weather. Sowing date had a pronounced effect on grain yield and grain N content in all three years. In 1989 and 1992, the earliest-sown barley (January or February) gave significantly greater yields than latersown crops (March and April) in five of the six experiments. The earliest-sown barley gave the lowest grain N in all six experiments and there was a gradual and significant increase in grain N content as sowing date was delayed. In 1993 the earliest-sown barley (February) gave significantly lower yield and greater grain N than the March-sown crop in all three experiments. The lower yield of the February-sown barley in 1993 was due to the significantly reduced number of grains/ear. The Aprilsown barley gave significantly lower yield and greater grain N than the earlier-sown crops in eight out of the nine experiments. In 1989 and 1992 only one of the six experiments, Ferns 1992, gave a significant yield response to increased rate of N (125 kg/ha). But in 1993, 125 kg N/ha significantly increased grain yield in all three experiments and 150 kg N/ha gave a further significant increase in yield in two of the experiments. Increasing increments of fertilizer N significantly increased grain N in all nine experiments.

Cardiovascular risk factor changes in the Kilkenny Health Project

The Kilkenny Health Project was a community research and demonstration programme which aimed to reduce risk of cardiovascular disease in a county in the south-east of Ireland with a total population of approximately 70,000. The health promotion programme was carried out in Kilkenny from 1985 to 1992. Outcome evaluation was by means of population surveys of independent samples of men and women aged 35 to 64 years in Kilkenny (n approximately 800) and in the reference county (n approximately 600) in 1985/1986 and in 1990/1991. Survey methods for health behaviour questionnaires and risk factor measurements were similar to those of the WHO MONICA Project. Mean systolic blood pressure (SBP) declined significantly (P < 0.01) in men and women in both counties, from 144.0 by 5.4 mmHg and from 143.2 by 5.4 mmHg in men and from 139.5 by 7.7 mmHg and from 136.5 by 6.6 mmHg in women in the intervention and reference counties. The prevalence of hypertension declined from 23.1% by 2.8% and from 26.1% by 6.0% in men in the two counties. Prevalence declined from 24.1% by 6.2% (P < 0.05) in women in the intervention county but was unchanged, increasing by 0.5% from 17.5%, in women in the reference county. Mean serum total cholesterol declined from 6.04 mmol.l-1 by 0.09 mmol.l-1 and from 6.00 by 0.44 mmol.l-1 (P < 0.01) in men and from 6.01 by 0.36 (P < 0.01) and from 5.90 by 0.31 (P < 0.01) in women in the intervention and reference counties, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

The Variscan fold-thrust belt of southeast Ireland and its control on early Mesozoic extension and deposition: a method to predict the Sherwood Sandstone

Abstract The Sherwood Sandstone Group (SSG), of Early Triassic Scythian age, contains attractive fluvial and aeolian sandstone reservoirs in the basins between Ireland and Britain (Morecambe Bay gas field, 6.5TCF) and in southern England (Wytch Farm oil field, 300 MMBBL). While the SSG is very thick in the northern portions of the Mesozoic basin system, it is thinner and generally less well preserved in the southern portions of the Mesozoic basin system which are underlain by the Carboniferous aged Variscan fold-thrust belt. Previously it has been suggested that the SSG was deposited during a time of rifting, and consequently its variable presence was attributed to wells penetrating positions within fault blocks that were high and devoid of syn-rift deposition. Data examined in this study from the East Irish Sea Basin and from the South Celtic Sea Basin, however, suggest that the SSG was deposited in palaeotopographic lows, the positions of which were controlled by erosion around massifs and resistant thrust belt hangingwalls that formed the palaeotopography. Furthermore, the evidence presented suggests that rifting occurred during the deposition of the Upper and Middle Triassic Mercia Mudstone Group (MMG), which is often defined as a post-rift succession. Successful prediction of the areas of SSG deposition depends on the ability to reconstruct the Early Triassic palaeotopography as it was controlled by the Carboniferous thrust belt morphology. A reconstruction of the Variscan thrust belt is presented, which is based on onshore surface geology, thrusts and transfer faults from published onshore mapping, published offshore thrust plane reflector mapping, gravity data showing lineaments and indications of granite plutons, and a set of observations from well and seismic data. Some thrusts are postulated by observations of reactivation during Mesozoic extension. A set of predictive tools has been developed for identifying the presence of the SSG. Determination of the presence of the SSG on seismic reflection data is often difficult. Where the data quality is poor, we postulate that there is a better chance of finding the SSG where halites are found in the overlying MMG. This empirical relationship is believed to occur because rifts developed over SSG foreland and intermontane valleys were near sea-level, allowing marine incursions and salt precipitation. By contrast, rifts that developed in high topographic areas were above sea-level and not subject to marine incursion. Additionally, the degree of deformation seen in the pre-Triassic section on seismic data can be used to predict the position of the Variscan Front and thus the topographically low, sand-prone areas overlying the Carboniferous foreland basin. A palaeogeographic map is presented, incorporating the analysis of all of these datasets and utilizing a comparison to the topography of the exposed Ouachita Mountains of the southern USA.

Predictive model for the development and distribution of Triassic reservoir sands offshore southeast Ireland, based on seismic sequence geometries at the Variscan unconformity

Predictive model for the development and distribution of Triassic reservoir sands offshore southeast Ireland, based on seismic sequence geometries at the Variscan unconformity

Intra-Ordovician deformation in southeast Ireland: evidence from the geological setting, geochemical affinities and U—Pb zircon age of the Croghan Kinshelagh granite

AbstractThe Croghan Kinshelagh alkali granite intrudes a cleaved volcano-sedimentary sequenceon the border of counties Wicklow and Wexford in southeast Ireland. U-Pb dating of zircons fromthe granite indicate a mid-Caradoc emplacement age of 454 ± 1 Ma. The Duncannon Group hostrocks form the southwestern end of the Avoca Volcanic Belt, a Mid-Ordovician (Caradoc) sequenceof acid and intermediate lavas and volcaniclastics. Dolerite dykes intrude the granite; elsewhere in theregion dolerites are generally associated with volcanic rocks. The main, Dl deformation within theDuncannon Group rocks is manifest as a steep Dl cleavage generally regarded as a product of LateCaledonian regional deformation in southeast Ireland. The Croghan Kinshelagh granite showsstrong geochemical coherence with subalkaline varieties of the Caradoc volcanic rocks; relativelyhigh Th, Y, Nb and REE contents set it apart from any other known granite type in southeastIreland. Together with the geochemical evidence, the age determination of 454 Ma indicates that theCroghan Kinshelagh granite was generated and emplaced during Ordovician volcanism in southeastIreland. Volcanism was closely followed by penetrative deformation and emplacement of the granite.The intra-Ordovician deformation may have been a consequence of closure of the Iapetus Ocean ormore localized events such as accretion on the hanging wall of the subduction zone. The age of theCroghan Kinshelagh granite provides an important datum for Ordovician volcanism and subductionin southeast Ireland.