Farming Barramundi

Research into the culture of barramundi began in Australia in 1984 with studies carried out by the Queensland Government. The work was initially aimed at adapting culture techniques developed in Thailand to Australian conditions. Following the evident success of preliminary research, the first commercial barramundi hatchery and farm was started in 1986 in Mourilyan Harbour, North Queensland (Schipp, 1996).

Barramundi are currently being farmed in Queensland, Northern Territory, South Australia, New South Wales and Western Australia. Queensland's barramundi industry has experienced the greatest expansion over recent years with commercial aquaculture production of plate-size fish growing from zero in 1986 to 349.4 tonnes (t) in 1996-97, worth $3.44 million (Lobegeiger et al., 1998). Estimated national production in 1995-96 was 529 tonnes, worth $5.83 million (Brown et al., 1997).

Barramundi Geographic Distribution

Globally, barramundi are widely distributed in the Indo-West Pacific region from the Arabian Gulf to China, Taiwan, Papua New Guinea and northern Australia. In Australia they are distributed in tropical coastal and fresh waters from the Ashburton River in Western Australia to the Noosa River in Queensland (Schipp, 1996) (Figure 1).

Figure 1 : Map showing the distribution of Barramundi in Australia

Barramundi Habitat

Barramundi move between fresh and salt water during various stages of their life cycle. Mature barramundi live in estuaries and associated coastal areas or in the lower reaches of rivers. Larvae and young juveniles inhabit seasonal brackish-water swamps associated with estuaries and older juveniles are found in the upper reaches of rivers (Schipp, 1996).

Barramundi Biology

Barramundi are euryhaline, meaning they can live in both fresh and salt water. However, barramundi eggs and larvae will only survive in brackish or salt water (salinities between 22 and 40 parts per thousand (ppt)) and for this reason all breeding takes place in river mouths and bays near areas of suitable nursery habitat. Areas such as mangrove swamps and low-lying land that becomes flooded during spring tides and monsoonal rains provide ideal habitat for juvenile barramundi (Schipp, 1996).

Barramundi become sexually mature between two and three years of age. In the wild, most fish first mature as males and participate in one or more spawning seasons before undergoing a sexual change (protandry), becoming functional females by the next breeding season (Schipp, 1996).

As a general rule, fish less than 80cm length are usually males and those greater than 100cm are females. However, this is not always the case as sexually precocious (fish that mature and change sex at a smaller than usual size) populations of barramundi are known to occur in the Northern Territory and Queensland. Broodstock held under captive conditions have been found to change sex to females at a smaller size than wild fish. This may be the result of the captive environment or hormone treatments used during the spawning season (Schipp, 1996).

In their natural environment, spawning takes place at night around the time of the slack tide and appears to be related to the lunar cycle. Nights following full and new moons are the periods of greatest spawning activity (Schipp, 1996). Peak spawning periods are November-December and February-March (Makaira, 1999).

 Informtation courtesy of the WA Department of Fisheries