The economies of some remote North Island coastal communities are at risk from the mass deaths of farmed juvenile oysters.
About half of the farmed Pacific oysters due for harvest next year have died mysteriously on marine farms stretching from Parengarenga Harbour in the Far North to Ohiwa in the eastern Bay of Plenty.
The Ministry of Agriculture and Forestry has taken 250 samples of juvenile oysters to try to find out what has caused the deaths.
Aquaculture New Zealand head Peter Vitasovich, who has a marine farm on the Coromandel Peninsula, says up to 80% of juvenile oysters have died, compared with between 5% and 10% in normal times.
"It's something that it has happened in France and Britain previously," he said. "But it's the first time it's happened in New Zealand.
Mr Vitasovich says there will be no impact on the present harvest, but the industry is predicting a substantial shortage of oysters for the next two years.
The Oyster Industry Association expects farms to recover because the surviving oysters appear to be unaffected by the problem.
"We'll probably end up with a more resistant oyster," says chairman Callum McCallum.
But in the meantime, it would be tough on those rural communities who relied on oyster processing as one of its main employers, he said.
"There's not a lot of employment in these areas, that's for sure."
