Oyster farmers on Wagonga Inlet are hoping the latest round of testing will give them the all clear to begin harvesting again after the NSW Food Authority closed the estuary on Thursday after due to an algal bloom. High concentrations of Pseudo-nitzschia species were detected in the waters of the inlet last week, which can lead to amnesic shellfish toxins.
The authority is monitoring the situation and advises to only eat shellfish harvested under a recognised commercial program. Commercial shellfish harvest in the area has ceased and product in the marketplace is not affected. The general public are warned not to eat any shellfish from Wagonga Inlet until further notice.
Narooma Oyster farmer David Maidment said the latest samples taken this week had just been sent off with the results expected on Friday afternoon. He was hopeful this latest algal bloom would be shown to be declining.
“Hopefully the number of cells per litre would have declined but we won’t know till Friday,” Mr Maidment said.
The same species of algae was first detected after the Gulaga Mountain fire of 2010 that was followed by heavy rain, which Mr Maidment said washed excess nutrients into the estuary.
It seems a similar situation has occurred this year with an extended dry period late last year and earlier this year followed by substantial rain, he said. “Conditions were just right with a an extended dry period, followed by rain,” he said.
Narooma Bridge Seafoods meanwhile was flooded by concerned phone calls from people who had purchased oysters after the closure was announced last week. But owner Sophie Wiersema said the shop had been selling unaffected oysters from Tuross and Merimbula lakes and so consumers did not have anything to worry about.
Algal blooms can occur anywhere along the coast and are normally the result of the surge of nutrient rich deep ocean water onto the continental shelf, and can often also be seen after rainfall events in estuaries.
It is also still too early to say whether the closure will be in place for the upcoming Narooma Oyster Festival next month, but organisers always source the oysters from inlets around the South Coast and so are not too worried.