Owner Rick York of the Ohiwa Oyster Farm said his farm was struck on November 19/20 and hit about a fair amount of stock for next year.
While it’s killing the spat, the virus is not affecting public health, says York.
The oysters are still quite edible.
He said however the there will be a huge shortage throughout the country next year.
Mortality rates this year are 30-80%, in a normal year they are 5-10%.
The virus identified as ostreid herpesvirus-1 (OsHV-1) has been found by MAF Biosecurity in oyster samples from affected farming areas.
OsHV-1 is not a World Organisation for Animal Health listed disease, meaning there are no trade issues.
It has been found in oysters in many countries including within Asia, North America, Europe and Australia where it has been associated with die-offs.
The virus is thought to have been in New Zealand for some time, with reports of its presence as early as 1992.
MAF believes that the mortality is likely to be caused by a range of factors, triggered by unusually warm water temperatures. There has been no detection of any problem with oysters outside of the affected areas in the Eastern Bay of Plenty and Northland.
MAF will continue to work closely with the industry to identify other causes of the event and ways future production can be managed.
The Pacific oyster industry is worth about $30 million each year. More at Sunlive.co.nz