Murray cod introduced to volcanic crater lake to boost tourism and eat carp

Australia Broadcast Center

09-05-2025

Hundreds of kilograms of Murray cod have been introduced into a lake in a volcanic crater, creating an instant tourism attraction and helping control pest fish.
The pond-grown fish were driven from Griffith, New South Wales, to Mount Gambier, South Australia, and released into the Valley Lake this week.
Recfish SA executive officer Asher Dezsery said the fishery was the state's first with cod up to a metre long, making the lake an instant "trophy fishery".
The group has previously released cod fingerlings in South Australian reservoirs, but this time opted for more mature fish.
"These fish will grow up to 20-30 kilograms ultimately," Mr Dezsery said.
"People go to the Riverland to catch big fish, they go to Victoria to catch big fish, and now they can come to Mount Gambier to catch big Murray cod that they're proud of.
"If people can come here and bring their boats, and bring the family, have a barbecue, that's fantastic."
Beyond the tourism benefits, the cod will also help control the invasive European carp in the lake.
"Carp ruin the environment by digging up the bottom," Mr Dezsery said.
"They increase turbidity, which is cloudiness in the water, and they also have a real impact on native fish by eating juveniles and eggs."
Mr Dezsery said the cod would eat juvenile carp and had helped limit the carp population in reservoirs.
"As it warms up, those carp will continue to spawn, but those cod will just continue to chip away at those juveniles," he said.
Murray Cod Australia's Rachel Guest was on board as the fish were transported to their new home.
"They're lucky that they're going to be able to spend the rest of their days living in this beautiful lake," she said.
"It's such a suitable environment for them.
"They're going to thrive and they're going to adapt very quickly."
Ms Guest said the company released about 1 million cod each year into public waterways.
"South Australia, Victoria, New South Wales, Queensland — we've all got problems with carp," she said.
Mr Dezsery said with recent algal blooms in water off SA's coast it was important to provide options for freshwater fishing.
"We want to be providing other options so we're not pressuring those fish stocks over and over," he said.
Due to Murray cod being a threatened species, the Valley Lake fishery will be restricted to catch and release fishing.
"We want to leave them in the water as much as possible, and use lures instead of bait, with barbless hooks where [fishers] can," Mr Dezsery said.