Mangrove jack breeding breakthrough at National Marine Science Centre

In a first for New South Wales, mangrove jack have been successfully bred in captivity at Southern Cross University’s National Marine Science Centre is Coffs Harbour.

The breeding program, led by Dr Ken Cowden from the National Marine Science Centre, has successfully hatched more than 4000 fingerlings (baby fish) which are now 10 weeks old and 50mm in length.

Minister for Primary Industries Katrina Hodgkinson congratulated the University’s National Marine Science Centre this week (Thursday March 5) for successfully breeding Mangrove jack in captivity for the first time in NSW.

“This is a remarkable achievement and advancement in the delicate science of breeding fish, and was made possible by funding from the NSW Recreational Fishing Trust,” Minister Hodgkinson said.

“Hatchery production of mangrove jack is extremely difficult and an achievement only matched by a very small handful of other hatcheries Australia-wide.

“Mangrove jack is an excellent sport and food fish and the latest breeding success will have wider implications for the aquaculture and aquarium industries.”

Dr Ken Cowden said mangrove jack was a native warm water fish.

“Their unique lifecycle involves spawning in seawater at offshore reefs. Later the larvae migrate into estuaries and even right up into the freshwater.

“Because their lifecycle involves moving between fresh and saltwater, it makes the species vulnerable to impacts from the construction of dam walls and weirs which often prevent access to the freshwater habitat.

“Therefore, breeding for freshwater impoundment stocking is a great breakthrough.

“The eggs are only 0.8mm in diameter, and the newly hatched larvae just over 2mm, making the species a great challenge for hatcheries to produce.

“It is because of this difficulty that the recent success at the National Marine Science centre is so significant,” he said.

Southern Cross University, in conjunction with the Department of Primary Industries, hopes to stock the fish into Clarrie Hall Dam, a freshwater location in the Tweed Shire of northern NSW, in coming weeks.

The projects to source brood stock and then breed the mangrove jack were funded by two NSW Recreational Fishing Trust grants worth a total of $130,000.

Visit The NSW mangrove jack breeding and stocking project Facebook page for more information about the project.

The Minister said the NSW recreational fishing industry generated about $1.6 billion into the state’s economy each year and creates about 14,000 jobs.
Photo: Dr Ken Cowden with the mangrove jack fingerlings.