MAF and Marine Farmers Investigate Oyster Deaths

2 December 2010

The New Zealand Oyster Industry Association for Aquaculture New Zealand and MAF Biosecurity New Zealand are working together to investigate unexplained juvenile Pacific Oyster deaths on marine farms in the upper North Island.

Aquaculture New Zealand CEO Mike Burrell says since mid November farmers have seen an increase in the mortality rate of young oysters (known as spat) on farms from the Bay of Plenty in the east and from north of Kawhia in the west.

“Typically mortality rates for cultivated Pacific Oysters are between five and 10 percent.  This year, however, the rates on some farms have varied between 30 to 80 percent which is very concerning for the industry,” Mr Burrell says.

MAF has its aquatic disease specialists on the case and has taken approximately 250 samples for analysis to try and determine what is causing the die-back. 

MAF Response Manager Richard Norman says the investigation is still in its early days and to speculate on the cause of the deaths and any likely impacts would be premature.

“What is clear is that both MAF and the industry understand the urgency around the issue and the need to identify the problem and find ways to address it,” Dr Norman says.

The New Zealand Food Safety Authority says there is nothing to suggest any food safety concern in New Zealand oysters, whether distributed for local consumption, or exported.

The main impact of the recent increase in mortality is the potential to reduce the amount of juvenile oysters available for stocking oyster farms for 2011 harvests.

There has been no detection of any problem with other oysters, including New Zealand’s renowned Bluff oysters.

For further information contact:
Lesley Patston, Senior Communications Adviser, MAFBNZ
Phone 029 894 0163

Tom Hollings, Executive Officer to New Zealand Oyster Industry Association
Phone 09 378 7001 or 027 495 3957