The report describes the work of Dr Peter Matthiessen and colleagues at MAFF's Centre for Environment, Fisheries and Aquaculture Science (CEFAS). The studies, reported by ENDS in June, found that male flounder caught in some estuaries produced a female yolk protein called vitellogenin and had feminised sex organs (ENDS Report 281, p 13 ). Both effects are symptoms of exposure to oestrogenic substances.
The most seriously affected fish were found in the Tees, Tyne and Mersey estuaries - areas which receive substantial volumes of industrial effluents. By contrast, fish in estuaries such as the Thames, which receives large volumes of domestic sewage effluents, were relatively little affected. Dr Matthiessen has suggested that the effects may be linked to more persistent industrial pollutants which remain in sediments. His current research is aimed at isolating the compounds responsible.
In a press statement on the report, MAFF warned that "it would be unwise for anglers to eat catches from any waters which may be polluted". When pressed for further details, a spokesman told ENDS: "It is up to the Agency to comment....it is their job to know where polluted waters are."
However, an Agency spokeswoman would say only: "We are not experts in food safety so we cannot advise on whether it is safe to eat fish. I would have thought that was MAFF's responsibility." Although the Agency can provide information on the general chemical and biological quality of waters, there is no simple relationship between this and whether fish are safe to eat.
Despite MAFF's general responsibility for food safety and its monitoring of commercial offshore fisheries, it has not addressed the issue of whether freshwater or estuarine fish are safe to eat. However, this is not the first time the issue has arisen. Concern was raised in 1991 after a research report found that Mersey fish were heavily contaminated with PCBs, mercury and organochlorine pesticides. MAFF responded with the same non-specific warning against eating fish from "polluted waters" (ENDS Report 200, pp 21-24).
The Agency and its predecessor, the National Rivers Authority, have also refrained from issuing advice on fish consumption, even though their research has shown that fish from areas like the Mersey contain lead and mercury in excess of established food standards (ENDS Report 233, p 8 ).
The situation is in sharp contrast to the USA and Canada, where "fish consumption advisories" are issued and used as an indicator of environmental quality. In the USA, the advisories are published by state authorities under the guidance of the Environmental Protection Agency and may warn against eating any fish or suggest limits on consumption, particularly for high-risk groups such as pregnant women and children. In 1997, 8.2% of US river lengths and 16.5% of lake areas were covered by advisories. The major contaminants of concern are mercury, PCBs, dioxins and organochlorine pesticides.
1 Oestrogenic endocrine disruption in flounder from United Kingdom estuarine and marine waters, free from The Library, CEFAS, Remembrance Avenue, Burnham-on-Crouch, Essex CM0 8HA.