Salmon farmer Tassal says growth and death rates among its fish in Tasmania’s Macquarie Harbour have been in line with expectations despite challenging summer conditions.
Tassal on Tuesday acknowledged that the island state’s west coast had an unusually hot and dry summer, bringing challenging dissolved oxygen levels and temperatures.
But, Tassal said, overall deaths and growth among its salmon had been in line with expectations and long-term strategies, and conditions had improved over the past two weeks.
“Environmental conditions are also in line with expectations with the science undertaken by both the salmon industry and the Tasmanian government underpinning the regulation of salmon farming in Macquarie Harbour,” Tassal chief executive Mark Ryan said.
“All of Tassal’s fish stock are from our selective breeding program which has focused on breeding fish adapted for Tasmanian conditions – meaning they are more resilient to higher temperatures and challenging water conditions.”
The company’s strategies for such conditions included more frequent net-washing and reviewing feeding practices, Mr Ryan said.
He added that wind, rain, and air temperature influenced dissolved oxygen levels.
“Temperatures have cooled, and Tassal sites have seen a dramatic oxygen recharge over the past two weeks,” Mr Ryan said.
Also, bottom-water dissolved oxygen levels had increased.
On Friday, rival salmon farmer Huon Aquaculture said conditions in Macquarie Harbour had become challenging since December because of hotter temperatures and reduced dissolved oxygen and that had led to slower fish growth.
It said reduced growth rates were expected to affect future production volumes and fish cost.
Shares in Tassal were four cents lower at $3.80.
Huon Aquaculture last traded at $3.60.