There may be a recession happening somewhere in New Zealand, but the Southland fishing industry which today began selling this year's harvest of Bluff oysters says it hasn't hurt sales of the delicacy.

"The demand's been amazing," said Barnes Oysters manager Graeme Wright, of Invercargill, whose factory handles about half of the oysters caught.

His operation opened with about 4000 dozen caught yesterday, but Mr Wright said bad weather had stopped the fleet of 11 boats going out again this morning.

"They've been going pretty quick - unfortunately the boys didn't get out this morning," he said.

Processors had not seen any drop-off in demand through customers cutting back on their spending, he said.

His company's Invercargill shop is selling oysters for $20/dozen, the same price as last year.

Another retailer, Greg King of King's Fish Market, said customers had been waiting when his first oysters went on sale at 9.30am, priced at $23/dozen, also the same as last year.

Fisheries scientists say the catch looks to be the biggest and best seen in the past five years, after the parasite Bonamia exitosa killed an estimated billion oysters between 2000 and 2003.

"It's gradually building back up and this year they're looking bigger, meatier and healthier than ever," said Keith Michael, a coastal fisheries scientist with the National Institute of Water and Atmospheric Research (Niwa).

"That's good news for oyster lovers."

Oyster dredgers in Fouveaux Strait have again voluntarily limited their catch to 7.5 million, half the allowable commercial catch, to help the population recover from disease. This is despite preliminary results from a scientific survey suggesting there is scope for the annual catch to be boosted to 10 million, possibly providing enough oysters to export to Australia.

Skipper of The Toiler and Bluff Oyster Festival chairman John Edminstin told the Southland Times the oysters his crew dredged were all of good quality.

And Ariel II skipper Anthony Fowler, a veteran of 41 years in the industry, said the quality of this year's harvest was comparable with last year, which was the best season for years.

The oyster season finishes on August 31.