§ 33. Mr. Alton
asked the Secretary of State for the Environment if he has yet received a report on the causes of the death of over 2,000 birds in the Mersey Estuary.
§ Mr. Heseltine
No. This is a regional matter which is being handled by the North-West water authority in co-operation with local industry as well as statutory bodies and voluntary wild life organisations. I understand that relatively high levels of lead have been found in the organs of dead birds, although this has not yet been confirmed as the cause of death.
The source of the lead has not been determined, and tests are still being made on samples of surface sediments and organisms from the mud flats of the estuary where the birds are known to feed. Results to date show no change in metal content from the normal level determined by annual survey ince 1974.