§ Dr. David Clarkasked the Minister of Agriculture, Fisheries and Food if he will quantify the substantial agricultural benefits referred to by the Minister of State the noble Lord, Lord Belstead, at a luncheon given by the 534W Association of Drainage Authorities on 20 November that would have accrued if the pump drainage of North Duffield Carrs had been approved.
§ Mrs. FennerThe agricultural benefits that would have accrued if the Ouse and Derwent Internal Drainage Board's scheme for pumped drainage of North Duffield Carrs had been approved for grant have been evaluated at around£125 per hectare. They would have arisen from the more efficient use of the land for livestock.
§ Dr. David Clarkasked the Minister of Agriculture, Fisheries and Food what response he has made to the critique made by conservation bodies of the economic justification made by the Ouse and Derwent Internal Drainage Board for the pump drainage of North Duffield Carrs, in particular the charge that the cost benefit methodology employed by the Internal Drainage Board was at variance with Government approved guidelines.
§ Mrs. FennerThe critique undertaken by conservation bodies of the economic justification made by the Ouse and Derwent Internal Drainage Board for pump drainage of North Duffield Carrs was taken fully into account in the consideration of the board's application for grant-aid.
§ Dr. David Clarkasked the Minister of Agriculture, Fisheries and Food if the programme of testing wildlife, particularly birds of prey, for residues of DDT, Dieldrin, Aldrin and Endrin will continue; and whether there has been an overall increase or decline in the residues of these products in the tissues and eggs of wildlife populations sampled in the periods (a) 1970 to 1974, (b) 1975 to 1979 and (c) 1980 to the present.
§ Mrs. FennerCurrent studies on residue monitoring in birds of prey undertaken by the Institute of Terrestrial Ecology on behalf of the Nature Conservancy Council will continue until 1986. A decision on whether or not to continue the monitoring after 1986 will be taken early in that year.
The most-sampled and best studied species are the sparrowhawk, kestrel and heron. Liver residues of DDE (the main fat-soluble metabolite of DDT) in kestrels have decreased throughout the periods listed; in herons it decreased during the early 1970s and early 1980s but changed little in the late 1970s; in sparrowhawks there has been little change. HEOD (an active ingredient of both dieldrin and aldrin) residues in all three species showed no significant change in the early 1970s and decreased in the late 1970s. The decrease continued into the 1980s in the heron. Endrin is not included in the monitoring scheme.
Only aldrin is still used in agriculture and horticulture, the use of the other substances having been phased out since the 1960s.