The Little Douglas oyster growing area north-west of Coffin Bay reopened last week following a week-long closure.
The area was shut down as a precaution by the South Australian Shellfish Quality Assurance Program (SASQAP) due to marine planktonic diatom levels found with routine water testing.
Gazander Oysters co-owner Carly Thomson said it was stressful to have the Little Douglas Bay area shut and that unseasonably calm conditions throughout May were part of the cause of the marine planktonic diatom.
“We’ve had no wind or rain and what would normally disperse the marine plankton hasn’t been there. Normally April is really calm, but May has also been extremely calm,” she said.
“We use wind as part of our farming practice to condition the oysters with our suspension lines and we certainly manipulate weather patterns to reduce the workload on people to get the shape and condition that we want on the oysters.
“We haven’t had that and that’s why there was an unusual number of marine planktonic diatom that was suspicious.”
Ms Thomson said the SASQAP water testing alerted them to the increased levels and as a result, the bay was shut to harvest.
She said it was unusual for Little Douglas Bay to be shut.
“This is something that occurs very regularly in Tasmania and on the east coast because they are more densely populated, but because we are less populated the water is so pristine this rarely occurs here,” Ms Thomson said.
“This was an environmental anomaly that we might not see for another 10 years.”
She added SASQAP increased the water testing, and the meat tests were completely clear and the levels of the marine planktonic diatom had dispersed to a much safer level, allowing the area to reopen.
“Because we have such strict food safety, PIRSA licensing conditions and monitoring through SASQAP, we have a world-class system that alerts us of stuff before it gets to a point where it impacts the public.”
