• The oceanography of southwest Ireland: current research activities

      Raine, R.; Whelan, D.; Conway, N.; Joyce, B.; Moloney, M.; Hoey, M.J.; Patching, J.W. (Fisheries Research Centre, 1993)
      The coastal waters of Ireland are rich in physical features affecting both chemistry and biology. Amongst these are the tidal fronts of the Irish Sea (Le Fevre, 1986) and the Irish Shelf Front on the Atlantic coast lying along the 200m iso bath (Huang et al., 1991). Recently, an upwelling system has been described in the vicinity of the Fastnet Rock (Roden, 1986; Raine et al., 1990). Coastal upwelling systems are ecologically very important and are generally extremely productive, as nutrients brought up to the sea surface can stimulate extensive phytoplankton growth. This paper describes further satellite and ship-based investigations which are currently being carried out to examine the mechanisms driving the upwelling system and its effect on local ecology.
    • Polychlorinated Biphenyls and Organochlorines in By-Caught Harbour Porpoises Phocoena phocoena and Common Dolphins Delphinus delphis from Irish Coastal Waters

      Smyth, M.; Berrow, S.; Nixon, E.; Rogan, E. (Royal Irish Academy, 2000)
      Concentrations of 11 organochlorine (OC) pesticides and 10 individual polychlorinated biphenyls (PCB) in blubber and liver from 12 harbour porpoise Phocoena phocoena and eight common dolphins Delphinus delphis incidentally caught in fishing nets in Irish waters are presented. Female harbour porpoises had highest concentrations of OC in blubber and male common dolphins in liver. Harbour porpoises had higher mean concentrations of lindane (121-154 ng/g extractable lipid), dieldrin (116-121 ng/g) and  BHC (54-128 ng/g) but common dolphins had greater overall concentrations of DDT (9444-3998 ng/g). The predominant DDT metabolite was pp-DDE and for the chlordanes was t-nonachlor. Concentrations of ICES 7 PCB (liver-blubber) were similar in both species (4075-7999 ng/g in harbour porpoise and 4076-8945 in common dolphins). The sum of ICES 7 PCB in porpoises ranged from 3041-12270 ng/g extractable lipid in the blubber of females and from 2911-10429 ng/g in males and 798-11074 ng/g in the blubber of female common dolphins and 1555-15883 ng/g in males. Contaminant levels were generally similar to those reported from Scotland but lower than reported from Scandinavia. Ratios of DDT to DDE suggests that there are limited new sources of DDT into the Irish marine environment. These results provide a baseline for monitoring of persistent pollutants in the Irish marine environment.
    • A sensitive liquid chromatography/tandem mass spectrometry method for the determination of natural and synthetic steroid estrogens in seawater and marine biota, with a focus on proposed Water Framework Directive Environmental Quality Standards

      Ronan, J.; McHugh, B. (Wiley, 2013)
      RATIONALE: Trace levels of natural and synthetic steroid estrogens estrone (E1), 17b-estradiol (E2) and 17a-ethynyl estradiol (EE2) have been demonstrated to exert adverse effects in exposed organisms. E2 and EE2 have been proposed for inclusion in the Water Framework Directive (WFD) list of priority pollutants; however, the detection and accurate quantification of these compounds provide significant challenges, due to the low detection limits required. METHODS: A sensitive method combining ultrasonication, solid-phase extraction (SPE) and liquid chromatography/tandem mass spectrometry, with electrospray ionisation in negative mode (LC/ESI-MS/MS), capable of determining E1, E2 and EE2 at concentrations between 0.07 and 60 ng/L for seawater and between 0.4 and 200 ng/g wet weight in Mytilus spp. is reported. Recoveries at the limit of quantification (LOQ) ranged from 95 to 102% and 88 to 100% for water and tissue, respectively. Salinity (12 to 35%) and typical marine particulate matter loadings (between 10 and 100 mg/L) were not found to affect analyte recoveries. RESULTS: The first detection of E1 by LC/MS/MS in Irish marine waters (Dublin Bay, at 0.76 ng/L) is reported. Steroids were not detected in Galway Bay, or in any mussel samples from Dublin, Galway and Clare. The level of E2 detected in the dissolved water phase was below the proposed WFD Environmental Quality Standard (EQS) in other surface waters. CONCLUSIONS: The proposed method is suitable for the detection of E1, E2 and EE2 at biologically relevant concentrations and, due to the specificity offered, is not subject to potential interferences from endogenous E1 and E2 which often complicate the interpretation of estrogenic biomarker assays.
    • Stable isotope analysis of baleen reveals resource partitioning among sympatric rorquals and population structure in fin whales

      Ryan, C.; McHugh, B.; Trueman, C.N.; Sabin, R.; Deaville, R.; Harrod, C.; Berrow, S.D.; O'Connor, I. (Inter-Research, 2013)
      Stable isotope analysis is a useful tool for investigating diet, migrations and niche in ecological communities by tracing energy through food-webs. In this study, the stable isotopic composition of carbon and nitrogen in keratin was measured at growth increments of baleen plates from 3 sympatric species of rorquals (Balaenoptera acutrostrata, B. physalus and Megaptera novaeangliae), which died between 1985 and 2010 in Irish and contiguous waters. Bivariate ellipses were used to plot isotopic niches and standard ellipse area parameters were estimated via Bayesian inference using the SIBER routine in the SIAR package in R. Evidence of resource partitioning was thus found among fin, humpback and minke whales using isotopic niches. Highest δ15N values were found in minke whales followed by humpback, and fin whales. Comparison between Northeast Atlantic (Irish/UK and Biscayan) and Mediterranean fin whale isotopic niches support the current International Whaling Commission stock assessment of an isolated Mediterranean population. Significantly larger niche area and higher overall δ 15N and δ 13C values found in fin whales from Irish/UK waters compared to those sampled in adjacent regions (Bay of Biscay and Mediterranean) suggest inshore foraging that may be unique to fin whales in Ireland and the UK. Isotopic profiles support spatial overlap but different foraging strategies between fin whales sampled in Ireland/UK and the Bay of Biscay. Stable isotope analysis of baleen could provide an additional means for identifying ecological units, thus supporting more effective management for the conservation of baleen whales.
    • Survey of toxaphene concentrations in fish from European waters

      McHugh, B.; Nixon, E.; Klungsoyr, J.; Besselink, H.; Brouwer, A.; Rimkus, G.; Leonards, P.; de Boer, J. (2000)
      Toxaphene, a suspected carcinogen, is a broad spectrum chlorinated pesticide. The objective of this study was to provide information on the toxicological risks posed by toxaphene to the consumer of fish from European waters. The levels of 3 toxaphene congeners in various fish species from different geographical locations were determined. These data were then used to provide information on the exposure of toxaphene to the consumer of fish.
    • A test battery approach to the ecotoxicological evaluation of cadmium and copper employing a battery of marine bioassays

      Macken, A; Giltrap, M; Ryall, K; Foley, B; McGovern, E; McHugh, B; Davoren, M (Springer, 2009)
      Heavy metals are ubiquitous contaminants of the marine environment and can accumulate and persist in sediments. The toxicity of metal contaminants in sediments to organisms is dependent on the bioavailability of the metals in both the water and sediment phases and the sensitivity of the organism to the metal exposure. This study investigated the effects of two metal contaminants of concern (CdCl2 and CuCl2) on a battery of marine bioassays employed for sediment assessment. Cadmium, a known carcinogen and widespread marine pollutant, was found to be the least toxic of the two assayed metals in all in vivo tests. However CdCl2 was found to be more toxic to the fish cell lines PLHC-1 and RTG-2 than CuCl2. Tisbe battagliai was the most sensitive species to both metals and the Microtox® and cell lines were the least sensitive (cadmium was found to be three orders of magnitude less toxic to Vibrio fischeri than to T. battagliai). The sensitivity of Tetraselmis suecica to the two metals varied greatly. Marine microalgae are among the organisms that can tolerate higher levels of cadmium. This hypothesis is demonstrated in this study where it was not possible to derive an EC50 value for CdCl2 and the marine prasinophyte, T. suecica. Conversely, CuCl2 was observed to be highly toxic to the marine alga, EC50 of 1.19 mg l-1. The genotoxic effect of Cu on the marine phytoplankton was evaluated using the Comet assay. Copper concentrations ranging from 0.25 to 2.50 mg l-1 were used to evaluate the effects. DNA damage was measured as percent number of comets and normal cells. There was no significant DNA damage observed at any concentration of CuCl2 tested and no correlation with growth inhibition and genetic damage was found.
    • Toxicological risks to humans of toxaphene residues in fish

      Leonards, P.E.G.; Besselink, H.; Klungsøyr, J.; McHugh, B.; Nixon, E.; Rimkus, G.G.; Brouwer, A.; de Boer, J. (Wiley, 2011)
      A revised risk assessment for toxaphene was developed, based on the assumption that fish consumers are only exposed to toxaphene residues that differ substantially from technical toxaphene due to environmental degradation and metabolism. In vitro studies confirmed that both technical toxaphene and degraded toxaphene inhibit gap junctional intercellular communication that correlates with the mechanistic potential to cause tumour promotion. In vivo rat studies established the NOAEL for degraded and technical toxaphene at the highest dose tested in the bioassay. Toxaphene residue intakes from European fishery products were estimated and compared to the provisional tolerable daily intakes (TDIs) from various regulatory agencies including Canada, the United States, Germany. The estimated intake was also compared to a new calculated provisional MATT pTDI. The MATT pTDI is based upon new toxicological information (in vivo rat studies) developed on a model for environmental toxaphene residues rather than technical toxaphene. A MATT pTDI (1.08 mg total toxaphene for a person of 60 kg) for tumour promotion potency was adopted for use in Europe and is hitherto referred to as the MATT pTDI. These new data result in a better estimate of safety and a higher TDI than previously used. Based on realistic fish consumption data and recent baseline concentration data of toxaphene in European fishery products the toxaphene intake for the consumers of Germany, Ireland, Norway and The Netherlands was estimated. For an average adult fish consumer the average daily intake of toxaphene was estimated to be 1.2 µg, and 0.4, 0.5, and 0.2 µg for the consumers of Norway, Germany, Ireland, and The Netherlands, respectively. The toxaphene intake of these average fish consumers was far below the MATT pTDI of 1.08 mg/60 kg body weight. In conclusion, based on the most relevant toxicological studies and the most realistic estimates of fish consumption and recent concentrations of toxaphene in European fishery products, adverse health effects are unlikely for the average European consumer of fishery products. In no case is the MATT pTDI exceeded.
    • Utilising caging techniques to investigate metal assimilation in Nucella lapillus, Mytilus edulis and Crassostrea gigas at three Irish coastal locations

      Giltrap, M.; Macken, A.; Davoren, M.; McGovern, E.; Foley, B.; Larsen, M.; White, J.; McHugh, B. (Elsevier, 2013)
      Pollution by metals has been of increasing concern for a number of decades but at present, the mechanism of metal accumulation in sentinel species is not fully understood and further studies are required for environmental risk assessment of metals in aquatic environments. The use of caging techniques has proven to be useful for assessment of water quality in coastal and estuarine environments. This study investigates the application of caging techniques for monitoring uptake of 20 elements [Li, Na, Mg, Al, P, K, Ca, V, Cr, Mn, Fe, Ni, Co, Cu, As, Sb, Pb, Hg, Cd and Zn] in three marine species namely Nucella lapillus, Mytilus edulis and Crassostrea gigas. Stable isotopes were used to determine predatory effects and also used for modelling metal uptake in test species and to track nutrient assimilation. Metal levels were monitored at three different coastal locations, namely Dublin Bay, Dunmore East and Omey Island over 18 weeks. Significant differences in concentrations of Mn, Co and Zn between mussels and oysters were found. Correlations between cadmium levels in N. lapillus and δ13C and δ15N suggest dietary influences in Cd uptake. Levels of Zn were highest in C. gigas compared to the other two species and levels of Zn were most elevated at the Dunmore East site. Copper levels were more elevated in all test species at both Dublin Bay and Dunmore East. Mercury was raised in all species at Dunmore East compared to the other two sites. Biotic accumulation of metals in the test species demonstrates that caging techniques can provide a valid tool for biomonitoring in metal impacted areas.