Oysters still parasite-free

Bluff oyster testing shows samples remain free of the parasite Bonamia ostreae.

ALMOST 1000 samples tested after an oyster parasite was detected last month near Stewart Island have no infection.

The parasite, Bonamia ostreae, is capable of increasing mortality in oysters, but little is known of the species or how big an effect it could have if it became widespread.

Since three wild oysters were found infected, Biosecurity New Zealand has been gathering information to help determine the most appropriate response.

It has been retesting samples of oysters collected from Foveaux Strait as part of routine surveillance checks for Bonamia exitiosa, a similar parasite which has been in the region for decades.

An update last week advised it had tested samples from 39 Foveaux Strait sites. B. ostreae had not been detected in any of the 972 samples tested.

“Across all 68 sites, 94.6% of samples have been tested. We expect to complete testing on samples from the remaining 29 sites by late April.”

A public meeting planned to be held on Stewart Island had been postponed due to travel and accommodation issues.

“But, more importantly, we’ve looked at the information to hand and have decided that we don’t have sufficient new detail to warrant taking people’s time up with meetings,” the statement said.

The agency was committed to working through the situation with those most affected and would fully discuss the surveillance results and possible future scenarios within weeks, it said.

B. ostreae does not present any food safety issue and fresh Bluff oysters are safe to eat.