Frisky Bluff oysters not so plump

05 April / Evan Harding - Stuff

One of the reasons, he believed, was because they had been busy spawning.

It was thought oysters used a heap of energy in the spawning process, which had a short-term effect on their meat condition.

The meat condition had improved as the season, which runs until August, had progressed.

A significant oyster spawning event in Foveaux Strait normally took place once in every 6-10 year cycle, but there had been lots of reproduction for the last two summers, Wright said.

The spawning process was thought to be driven by environmental influences unique to the Foveaux environment.

Bluff oyster lovers would reap the benefits of the increased levels of spawning in six to nine years, when the baby oysters grew to legal size.

The spawning activity may have been just one of the reasons they weren’t plump early this season.

Wright said it was normal to see variations in the condition of the oysters, depending on climatic and environmental conditions in the strait at the time.

Oysters were sedentary, so required the plankton they fed on to move past them, and they required the conditions to be reasonable so they were able to feed.

The public consumption of the oysters had not slowed, Wright said.

“The market has been very strong.

“It’s quite incredible really, it never ceases to amaze me ... the amount of oysters eaten in Southland is staggering.”

Barnes Wild Bluff Oysters processed about 450,000 dozen oysters a season and about 130,000 dozen were sold in Southland and Otago.

“Southlanders are passionate about oysters.”

Test results for Bonamia exitiosia, which kills oysters and has been in Foveaux Strait fishery for decades, are expected in May.

The Bonamia levels varied year-to-year but the oyster boat skippers had not reported any visual signs of oyster mortality after four weeks of the season, Wright said.

The industry can take up to 14.95 million oysters from Foveaux Strait each season but it has given itself an initial limit of 7.5 million this season.

Wright said a decision would be made in coming weeks on whether to increase the quota slightly or keep it the same.

Ricky Ryan, Bluff oyster fisherman of 37 years who works on the Daphne-Kay boat, confirmed the quality of the oysters wasn’t good initially, but it had picked up.

“There’s heaps of young oysters [in the ocean] which is good for the future.”

On Wednesday, when contacted by Stuff, Ryan and his crew got 1700 dozen oysters.

When he started in the industry 37 years ago the boat he was on would dredge more than 6000 dozen oysters a day but Bonamia decimated the beds in the 1990s.

The Foveaux Strait oyster fishery was closed for three years in the 1990s to recover.

The Bonamia exitiosa in Foveaux Strait is a separate species to Bonamia ostreae which was found in oyster farms at Big Glory Bay, Stewart Island in 2017.

The oysters in the Big Glory Bay farms were removed to prevent the parasite from spreading to the Foveaux Strait wild oyster fishery.

Testing by the Ministry for Primary Industries has so far shown no signs of the Bonamia ostreae in Foveaux Strait.