§ Mr. Foulkesasked the Minister of Agriculture, Fisheries and Food what are the latest concentrations of caesium in fish in the Irish sea and Scottish coastal waters; and what percentage increase this represents over the concentrations found on a similar date on each of the previous five years.
§ Mr. MacGregor[pursuant to his reply, 24 November 1983, c. 391]: The most important species of fish—in radiological terms—from the Irish sea and Scottish waters are plaice from the Sellafield offshore area and cod from the Minch. The latest data available are fo 1982 and give concentration of caesium-137 of 510 Bq kg-1 and 23 Bq kg-1 respectively. The percentage changes ever the data for each of the previous five years are as follows. These figures are based on the mean concentrations for each year, since this is the quantity of radiological significance.
Year 137Cs Concentration (Bq kg-1) Percentage change (1982 compared with earlier years) Sellafield Plaice 1977 940 -46 1978 1,000 -49 1979 820 -38 1980 580 -12 1981 590 -14 1982 510 — Minch Cod 1977 41 -44 1978 48 -52 1979 42 -45 1980 35 -34 1981 44 -48 1982 23 —