Chemical contaminants in Irish estuarine and coastal waters, 1978 to 1988

Observations on the concentrations of heavy metals (mercury, cadmium, copper, lead and zinc) and chlorinated hydrocarbons (PCBs and the pesticides, lindane, dieldrin, DDTs and chlordanes) are presented. Sources comprise mussels and oysters from twenty six estuarine and coastal locations and in fin fish landed from all coasts. Data on heavy metals and nutrients in sea water and heavy metals in sediments for nine estuaries are also reported. Data were collected to comply with the Joint Monitoring Programme of the Oslo and Paris Commissions and with the Cooperative Monitoring Programme of the International Council for the Exploration of the Sea. The locations sampled included Boyne estuary, Dublin Bay, Wexford Harbour, Barrow estuary, Waterford Harbour, Cork Harbour, Bandon estuary, Tralee Bay, Shannon estuary, Clarinbridge, Kilkieran Bay, Clew Bay, Killary Harbour and Mulroy Bay. Four cases of elevated concentrations of cadmium, two each of copper, zinc and mercury and one of lead are reported. The general overall temporal trend in metal levels has been of stability or, in the case of more marked contamination, of reduction. The degree of organochlorine contamination was low in all the estuaries and shellfish growing areas monitored. No instances of contamination exceeding tolerance levels in shellfish and fin fish for human consumption were recorded. With very few exceptions, it was found that Irish coastal waters enjoyed exceptionally low levels of contamination.Funder: Marine Institut