After high rainfall throughout the Macleay Valley in mid-December, thousands of fish were killed due to acid sulfate from the Doughboy swamp near Clybucca washing into the river and impacting oxygen levels.

Fishermans Reach Oyster farmer and Chair of NSW Farmers Oyster Committee Todd Graham said the water was just starting to clear before more rainfall.

"From the rain in mid December we had a black water event where we had a small fish kill, the water just started to clear up and then we got the follow up rain throughout December and January and from then we've had a second black water event," he told the Argus.

"It's looking like we'll have a fair size oyster kill this time.

"The oysters can survive a certain period of time in the fresh water but when you have one on top of the other you start losing a few."

Mr Graham said this potential oyster kill, combining with the troubles of early 2020 will create problems for some farmers.

"Oyster farmers around the area are pretty stressed at the moment, there's a few of the farmers if they do get another big kill they may not be able to continue on," he explained.

"The way we get our oysters is you can catch them out in the wild or buy them from a hatchery, the wild caught oysters are the ones most farmers up here use, they take two and a half to three and a half years to grow and sell.

"So if we add kills from last year to this year then it's maybe another two and a half years until we have an income.

"Luckily a lot of the growers here are part-time and have second jobs so they do have some income at the moment but the full-time farmers where both partners have their only income from oysters are going to struggle."

Over the last couple of years Macleay River oyster farmers have been slowly building up their stocks, aiming to increase sales and these events will prove to be a major setback in improving the growth of the industry within the area.

"Everyone was just gearing up too, all the farmers were starting to build the river back up," Mr Graham said.

"Over the last four years I was slowly building up in sales, last year with what I had up there it should've been about 200,000 in sales, this year should've been closer to 300,000 in sales.

"I had a pretty good survival rate last year but I did still lose around 150,000 worth of mature oysters and this year is looking similar due to the black water events.

"Last year which were budgeting for about 180,000 in sales we had 20,000 in sales for the loss of product.

"One farmer basically lost 200,000 last year and he was planning to re-invest that whole thing back into the farm too."

Fortunately, Mr Graham said he finds ways to back up his products.

"I have oysters in different parts of estuaries, different parts get hit differently to have backups and I also use both wild caught and hatchery stock from the breeding program which is genetically bred to survive disease and water quality issues," he added.

The Christmas period marks a time of high demand for growers with oyster farmers supplying throughout various parts of the state but this year we lost these sales due to the events following the rain fall in December.

The majority of farmers throughout the Macleay River area send their product down to Sydney but only after all the local markets are met.

While you're with us, you can now receive updates straight to your inbox from the Macleay Argus. To make sure you're up to date with all the news, SIGN UP HERE.