Bluff oyster fisheries in rapid rebuild phase

Thursday, 27 June 2019

An optimistic picture was painted for the future of Bluff oyster fisheries during a select committee meeting in Parliament on Thursday.

Ministry of Fisheries inshore fisheries team manager Allen Frazer said at the Primary Production Select Committee meeting that reports had shown that the number of oysters in the fishery had significant fluctuations, driven by the disease bonamia.

Periods such as 2000 to 2002 showed rapid decreases, however the latest survey suggested the fishery was heading towards a period of rapid rebuild, Frazer said.​

There were low levels of bonamia in the fishery at the moment and there was a now large number of juvenile oysters after several years of poor numbers, he said.

**READ MORE:

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During the meeting, Frazer was questioned about how the oysters were managing to live successfully despite the presence of the disease bonamia.

'It's not only the oysters themselves that are living with the disease, so are the fisheries,' he said.

He was also questioned if it was possible to raise the population numbers.  

Frazer said there were programmes that had been put in place to raise population but they have not made much of a change.

While it was known bonamia exitiosa was in Foveaux Strait since the 1980's, the discovery of Bonamia ostreae in Stewart Island created new concerns two years ago.

Bonamia ostreae is a parasite that is proven to have an impact on fisheries overseas and was first discovered in New Zealand in 2015 in Marlborough.

​Bonamia ostreae was discovered in Big Glory Bay, Stewart Island in 2017 and Frazer was questioned if the disease had been transported from Marlborough.

When the bonamia ostreae was discovered in Marlborough, the area was controlled and transportation could not occur so it was unlikely it came from Marlborough, he said.

He was unsure how the disease arrived at Big Glory Bay and would come back to the select committee with more information.

As a response to the discovery of bonamia ostreae in Stewart Island, the Ministry of Primary Industries ordered marine farmers to remove oysters that could be infected with the disease. 

In total $2.5 million in compensation had been given to oyster farmers with 27 of 40 complaints completed so far, Frazer said.

Fraser was questioned why MPI didn't remove the bonamia ostreae disease from Marlborough in 2015.

Control of the disease was seen as enough action at the time although eradication was considered, he said.

When questioned if bonamia ostreae could flare up again in the Foveaux Strait, Frazer said that regular monitoring at Big Glory Bay and Foveaux Strait had not shown signs of bonamia ostreae returning.

'If thats the case and continues to be the case this will be the first example of bonamia eradication in the world.'