• Contaminants in marine biota 1990 monitoring programme

      Nixon, E R; McLaughlin, D; Boelens, R G; O'Sullivan, G (Department of the Marine, 1991)
      In 1990, samples of fish from commercial catches landed in Ireland, and fish and shellfish collected at Irish coastal sites, were analysed in accordance with the requirements of the Joint Monitoring Programme (JMP) of the Oslo and Paris Commissions (OSPARCOM). The methodologies employed were consistent with JMP Purpose A: Significance to human health, and JMP Purpose C: Existing geographical distributions. The levels of heavy metals and chlorinated hydrocarbon compounds were generally low: well below the internationally accepted levels for protection of human health, and below the levels known to be of significance to marine life. Higher than Irish average levels were found in areas such as Dublin Bay, Cork Harbour, Mornington on the river Boyne, and the Barrow and Rogerstown Estuaries. These are all adjacent to densely populated and industrialised catchments and coasts. There were no cases of serious contamination.
    • Levels of metals and organic contaminants in mussels Mytilus edulis from Cork Harbour - 1989

      Boelens, R G; Nixon, E R; McLaughlin, D (Department of the Marine, 1990-07)
      This study of contaminants in mussels from outer Cork Harbour (Buoy no. 8) has shown that the levels of selected metals and organochlorine substances are generally low and at the lower end of the ranges measured in recent surveys of mussel populations at other European coastal sites.
    • Mercury concentration in fish from Irish waters in 1992

      Nixon, E; Rowe, A; McLaughlin, D (Department of the Marine, 1993-08)
      Fish landed at the major Irish ports and molluscs from the main growing areas were sampled during 1992 and analysed for total mercury content. Concentrations in fish species ranged from 0.015 to 1.02 mg/kg wet weight with a mean of 0.1, while in shellfish the concentrations were lower and ranged from 0.005 to 0.049 with a mean of 0.026. The mercury levels recorded in all fish sampled were within the standards for human health applied by the contracting parties to the Oslo and Paris Convention (OSPARCOM). The mean mercury concentrations in only two samples, redfish and crawfish from the west coast, showed levels close to the limit. These species are generally offshore and levels are associated with naturally-occurring mercury rather than with human activity. The survey confirms that Irish seafish of all kinds are effectively free from mercury contamination.
    • Mercury Concentrations in Fish from Irish Waters in 1994

      Nixon, E; Rowe, A; McLaughlin, D (Department of the Marine, 1995-09)
      During 1994, a total of 65 samples, covering the commercially important fish and shellfish species, were collected and the edible portion analysed for total mercury content in accordance with the European Commission's Decision of 19 May 1993. In fish, including prawns, the concentration of mercury ranged from 0.01 to 0.21 with a mean of 0.06 and in shellfish from 0.01 to 0.13 with a mean of 0.04mg/kg wet weight. These levels are low and are well within the maximum limits, 0.05mg/kg wet weight, set by the EC for mercury in fisheries products. This survey confirms previous studies that show Irish seafoods are effectively free from mercury contamination.
    • Monitoring of Shellfish Growing Areas - 1994

      Nixon, E; McLaughlin, D; Rowe, A; Smyth, M (Department of the Marine, 1995)
      To fulfil the monitoring requirements of the 1979 Council Directive 79/923/EC on the water quality of shellfish waters, water and shellfish samples were collected from 19 major shellfish-growing areas and analysed for physicochemical parameters and chemical contaminants. At each site temperature, salinity, pH and dissolved oxygen measurements were made and the area was inspected for the presence of petroleum hydrocarbons. Water samples were collected for suspended solids determinations. A representative sample of the shellfish from each area was collected and returned to the laboratory for metal and chlorinated hydrocarbon analyses. As in previous years, the water quality was good and conformed to guidelines and requirements of the Directive. Petroleum hydrocarbons were not observed in any of the shellfish waters or as deposits on the shellfish. Chlorinated hydrocarbon levels were very low, evidence of the clean, unpolluted nature of Irish shellfish and shellfish producing waters. Mercury and lead levels were consistently low, however, levels of cadmium in oysters from a number of areas were above average but did not exceed the Dutch human consumption tolerance value. It is known that oysters accumulate metals more readily than mussels and, considering the remoteness of many of these areas, the elevated cadmium levels are not considered to be anthropogenic in origin.