Bluff oysters under attack
Bluff oyster have come under threat after the discovery of a lethal parasite at two Stewart Island oyster farms.
The Ministry for Primary Industries confirmed the detection of Bonamia ostreae in two oyster farms on Stewart Island.
Bonamia ostreae has been in New Zealand since at least 2015 in the Marlborough Sounds and Nelson, but this is the first time it has been found in another area of New Zealand. The parasite can be fatal for flat oysters.
Ministry biosecurity surveillance and Incursion manager Brendan Gould said Bonamia ostreae was a naturally occurring parasite and was difficult to contain and eradicate as it was spread easily through ocean currents and on vessels.
‘‘We are concerned that Bonamia ostreae has been found in Stewart Island, and our pri- ority is on determining the extent of the problem and limiting further spread.’’
The ministry has been aware of the parasite in Stewart Island fisheries since May 24.
The ministry has reissued a controlled area notice legally restricting movements of some shellfish species, including their spat, into and out of Nelson, Marlborough Sounds and Stewart Island. It also legally restricts movements of farm equipment and vessels out of Stewart Island to limit further spread.
There is no food safety issue from eating oysters with Bonamia ostreae.
‘‘Our priority is on determining the extent of the problem and limiting further spread’’
It is the first time the parasite has been discovered outside of the Marlborough Sounds and Nelson.