Port Stephens oyster growers are holding their breath to see if millions of dollars worth of stock survives an influx of fresh, contaminated water into the catchment.
The floodwater changes the estuary's salt concentration, meaning the oysters are unable to feed.
Harvesting won't recommence until April 12 or when salinity levels reach 18 parts per million.
It is estimated the stoppage will cost the region's 36 growers at least $2 million in lost income.
The interruption also means Hunter consumers will be eating mostly imported seafood during Easter.
"It's only been a few days since the rain stopped. We won't know if we have lost any stock until 14 days has passed," Port Stephens Shellfish committee chairman Mark Hunter said.
"But we are much better placed than the guys up north."
In addition to oysters, the influx of fresh water has also stopped the harvest of school prawns.
Despite the impact of the floods, Newcastle Commercial Fisherman's Co-op chief executive Robert Gauta said he was confident that there would be enough oyster and prawn supplies for Easter.
"From time to time there are shortages of school prawns but there are always plenty of king prawns. We can bring them in from Queensland and South Australia if needed," he said.
"A lot of oysters were harvested just before the heavy rain and are in storage. We are also bringing in supplies from Coffin Bay, South Australia."
Drought destroys school prawn nurseries in the Hunter River, Tuggerah Lakes and Myall Lakes
Mr Hunter saidhe was hopeful the region's growers would bounce back quickly.
"If it stays dry I'm pretty confident we will be fine," he said.
"Unlike the April 2015 superstorm we haven't lost any infrastructure this time around."
He also credited the recent dredging of the Myall River entrance for reducing the impact of the fresh water.
"The situation would be worse if the entrance to the Myall River hadn't been dredged recently. It's important that it continues to be dredged on a regular basis."
Mid Coast Council and the State Government jointly funded the $1.7 million project.
