Greens voice concerns over levels of mercury in NZ fish

The Food Safety Authority's diet survey showed battered fish tested in Dunedin had a mercury level ten times that of battered fish in Napier. File photo / CityLife Wainuiomata

The Food Safety Authority has no concerns following claims there are huge fluctuations in mercury levels in fish sold in different parts of the country.

The Green Party is highlighting the authority's diet survey which shows battered fish tested in Dunedin has a mercury level ten times that of battered fish in Napier.

Fish in Dunedin has twice the level of arsenic than fish on sale in Auckland.

MP Sue Kedgley says swimming with sharks could be safer than eating some varieties of fish sold in New Zealand.

She says most fish are low in mercury however longer-lived predatory fish including shark or flake, swordfish, marlin and broadbill, tend to build up their mercury levels.

She says research published in the Medical Journal of Australia suggests that even relatively low levels of mercury can affect children's brain development.

Ms Kedgley is also raising the issue of the recent MAF Biosecurity decision allowing the importation of Vietnamese catfish farmed in the Mekong River to be imported in significant quantities to New Zealand despite concerns about water pollution in the river.

"Because we don't have mandatory country of origin labelling, no one will know if some of these Vietnamese catfish are turning up in the latest diet survey and explaining the high levels of mercury in some fish."

But Food Safety Authority Senior Programme Manager Cherie Flynn says it is not fair to compare the mercury results on a regional basis.

"The fish that we purchased in those four centres were one or at the most two purchases of fish made at two shops on one day."

Ms Flynn says overall trends show mercury and arsenic levels in fish are less than half of the weekly intake recommended by the World Health Organisation.

- NEWSTALK ZB