New rules allow the import of frozen fil' />

Next time you're enjoying a classic Kiwi dinner of fish and chips, think twice about what you're eating.

New rules allow the import of frozen fillets of Vietnamese catfish or basa, a super-cheap species farmed in the polluted Mekong Delta.

The move has raised concerns about health and the impact on the New Zealand fishing industry, and renewed debate on the need for compulsory country-of-origin labelling on food.

Basa imports were approved by MAF Biosecurity in the name of free trade and came into force on March 20.

The first major shipment - 15,000kg - was imported by Shore Mariner, one of New Zealand's largest seafood suppliers, in June.

Managing director Gerald Jurie said it had been largely sold to fish and chip shops and producers of ready meals and breadcrumbed fish.

Andrew Talley, of Talley's food group that campaigned against the change, said the fish is grown in the "most putrid and polluted waters anywhere in the world".

"It's harvested with slave labour, with no environmental regulations and no health and safety regulations, which enables them to produce a product at about a third of the cost of New Zealand product."

He said basa was sold as orange roughy, sole, tarakihi and ling in different countries, meaning consumers could be eating it without realising.

New Zealand Federation of Commercial Fishermen president Doug Saunders-Loder feared consumers would choose lower-quality fish because it was cheaper and said it was "ludicrous" to increase competition for Kiwi companies during a recession.

The World Wildlife Fund has concerns about the use of antibiotics and chemicals in basa farms. The potential presence of a toxic chemical called malachite green is a particular worry.

But MAF Biosecurity animal imports team manager Rachelle Linwood said a scientific risk analysis found the fish was safe to import.

"Under rules of international trade you can only not import a product if there's valid scientific reasons to not import it. As long as there's not biosecurity risks associated with it, we have to be able to import it."

The New Zealand Food Safety Authority said basa met the Food Standards Code and Food Act. Spokesman Gary Bowering said the authority could include the fish in a monitoring programmes if there was "sufficient evidence suggesting a food safety and/or suitability problem".

Jurie says people are more likely to fall ill after eating New Zealand fish because of our stringent import regulations.

He said basa was more environmentally sound than hoki, because it's farmed, meaning less damage to the natural marine environment.

Green MP Sue Kedgely said basa imports underlined the need for compulsory country-of-origin labelling on food.

"Voluntary labelling ends up as like a marketing tool for producers," she said. "If it's in their interest to say something's from New Zealand, they'll tell us, but if it's Vietnamese catfish they'll keep it from us. It's quite outrageous."

Taste test

It might not be much to look at, but how does it taste?

Gerald Jurie of Shore Mariner, the company behind the first major import of frozen Vietnamese catfish fillets to New Zealand, says it's a cross between butterfish and orange roughy.

"It's a white, moist fillet of fish with no bones."

None of the fish and chip shop owners in Auckland we spoke to said they sold basa.

Neil Kelsey of John Dory's in Herne Bay, uses fresh john dory, tarakihi or snapper and didn't like the sound of the new arrival.

"If it's from fresh water it wouldn't have much flavour and, by the sounds of it, might even have a muddied flavour."

Sear Tang at Herne Bay Fish Mart sells only fresh fish bought from the Auckland Fish Market each morning - usually snapper or tarakihi.

At Happy Takeaways in Westmere, John Lowe offers frozen hoki and more expensive snapper and tarakihi.

In our unscientific newsroom taste test, most people preferred tarakihi and snapper, but couldn't tell much difference between them.

The hoki was a clear loser, but at $2.50 for one fillet versus $5.50 for a piece of tarakihi at John Dory's, perhaps you get what you pay for.

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15,000
The number of kilograms of Vietnamese catfish imported into New Zealand in one shipment in June.

42
The number of countries that import Vietnamese catfish.

$6.50
The reported wholesale per-kilo price of Vietnamese catfish.

$11.50
The reported minimum wholesale per-kilo price of NZ fish.