South Australian oyster growers say the mass deaths of marine life at an Adelaide research facility will set their breeding lines back by about 12 months.
Large amounts of oyster spat, as well as fish including barramundi and snapper, have died of unknown causes at the South Australian Research and Development Institute (SARDI) facility at West Beach.
Growers said the state's oyster supply would not be directly affected, but about 70 per cent of SA's oyster breeding lines had been lost.
"This doesn't affect the oyster growers' supply of spat … they're produced by commercial hatcheries, so they'll still get their spat," said SA Oyster Growers Association deputy chairman Gary Zippel.
"But it is incredibly disappointing … we're desperately scrambling for alternatives to see if we can do another run or salvage something out of this.
"At this stage, it looks like we're nearly going to lose nearly a full year on a breeding program."
Coffin Bay is famed for its oyster production. (ABC Eyre Peninsula: Jodie Hamilton)
The spat in the breeding lines was being developed to be resistant to Pacific Oyster Mortality Syndrome (POMS), a disease that kills oysters in a matter of hours, first discovered in Australia in 2010.
Mr Zippel said SA growers may return to using SARDI's labs if the issue is resolved, or they may look to develop breeding lines in Tasmania.
The SA oyster industry was worth $58 million to the state last year.
Growers say they will still have access to oyster spat. (ABC Great Southern: Georgia Hargreaves)
Recreational fishers impacted
RecFish SA deputy chair Barry Brown said the loss of snapper, in particular, was a blow for recreational fishers, given a three-year snapper fishing ban across most of the state is due to end in November 2025.
"It's a major concern and really disappointing to hear that they have had a substantial dieback amongst the snapper fingerlings that they have been developing there, not to mention all the other stock," he said.
A one-year-old snapper in a breeding program at SARDI. (Supplied)
"It is early days so we don't know enough and they are saying it shouldn't delay anything, but time will tell.
"Developing snapper fingerlings to the stage where they can be released is not a short and easy process, so it is a concern."
Since 2021, SARDI has released hundreds of thousands of juvenile snapper into the Gulf of St Vincent, after breeding them at the facility.
The facility is based at West Beach in Adelaide. (ABC News: Bethanie Alderson)
Investigation underway
It has been speculated that the fish deaths were caused by dredging at West Beach, nearby SARDI's facility, which began in early October.
Primary Industries Minister Clare Scriven said the cause of the deaths was still being determined.
Minister Scriven speaks to media earlier this year. (ABC News: Justin Hewitson)
"There's been testing which has so far ruled out any diseases or infections," said Minister Scriven.
"It is, at the moment, not clear what's caused this."
The opposition's Nicola Centofanti MLC was highly critical of the situation.
"We're talking about significant losses … it's an absolute disaster for the state," she said.
An investigation into the deaths is underway.