§ Mr. AltonTo ask the Secretary of State for the Environment (1) what information he has as to the levels of mercury found in fish tested within the Mersey basin area;
(2) what information he has as to the levels of dissolved oxygen in the waters of the Mersey basin.
§ Mr. Moynihan[holding answer 29 November 1988]: As the hon. Member will be aware, the Mersey Basin Campaign is the long-term Government-launched initiative to tackle both water pollution and landward dereliction in this important part of the country. The Department works with many bodies and operational agencies in the campaign organisation, and they carry responsibility in the first instance for much of the detailed information involved.
On mercury levels the relevant tests are on fish for human consumption and, in fact, are carried out in Liverpool bay and the Irish sea—not within the Mersey basin area itself where there are no commercial fisheries. the latest information I have from sea tests is that the level of mercury in fish flesh is 0.2 mg per kg net weight, which is below the EC limit of 0.3 mg.
As to levels of dissolved oxygen in the Mersey system, detailed measurements are carried out by North West water authority as part of its operations. I suggest that the hon. Member should approach the authority direct for any detailed information, and interpretation, he may require. Meanwhile, I understand from the authority that levels of dissolved oxygen are increasing throughout the system, including trouble spots such as the upper estuary.