Barramundi

• Australian production (9,577t in 2021)

Barramundi are native to Australia, and are caught in wild fisheries and farmed. Farmed production exceeds wild fisheries production. Farmed barramundi are mainly produced on land in tanks and ponds, with a relatively small volume produced in the ocean in sea cages in Western Australia.

As an omnivorous species, barramundi are dependent on the fishmeal and fish oil in feed sourced from wild caught fish. However, they can be farmed on a diet relatively low in fishmeal and oil, and feed manufacturers continue to produce feeds with lower quantities of wild caught fish. Farmed barramundi has a better ‘wild fish in to farmed fish out’ ratio than farmed carnivorous finfish species such as Rainbow trout and Atlantic salmon. The amount of wild caught fish needed to produce fishmeal and oil for barramundi feed is approximately equal to the amount of farmed fish produced. This means that the farms aren’t taking out more fish from the ocean than they produce.

Farming barramundi also has a relatively low impact on the natural environment. Waste from land-based farms is adequately managed by the jurisdiction in which the farm is sited, and sea cage production in WA is situated in an area of high water movement, meaning waste is removed and adequately dispersed by water currents. In addition, wastewater from barramundi farms along the Qld coast is adequately treated and does not present a threat to the Great Barrier Reef. Careful planning of sea cages location and wastewater treatment is essential to ensure minimal environmental impacts.

Disease transfer from farmed to wild populations is not an issue in land-based production and minimal in sea cage operations.

• Northern Territory Barramundi Fishery (344t 2015)
• WA Kimberley Gillnet and Barramundi Fishery (52t 2016)

There are no formal stock assessments for barramundi stocks in NT or WA. The NT monitors the stock health of barramundi by assessing long-term catch records and by tagging and releasing fish and recording the number that are re-caught in commercial fisheries. There are concerns about poor recruitment of young barramundi into the population due to poor weather; however, the annual harvest of the stock is less than 5% of the population.

Fisheries in WA focus on only a few of the multiple stocks of barramundi. Fishing effort is low and newly established marine parks provide protection for some stocks from commercial fishing in some parts of the fishery, notably Roebuck Bay where all commercial effort has been removed from what was a major source of catch. There are no major sustainability concerns.

Threatened species caught in the NT and WA fisheries include dolphins, crocodiles and sawfish. The NT fishing industry has developed a Code of Practice that details the best methods to release bycatch alive. Given the wide distribution of the protected species caught and the moderate interaction rates previously recorded by independent observers, there are no indications the fisheries are causing population declines of any protected species. There are extensive areas closed to gillnet fishing in NT waters and recently established marine parks in WA that are likely to confer a degree of protection to endangered species.

There has been previous independent observer coverage in NT, where the program is due to begin again in 2018. There is no observer coverage in WA, which is a concern offset by the small scale of the fishery.

• QLD East Coast Inshore Fishery and Gulf of Carpentaria Inshore Fishery (663t in 2021, 626t in 2020)

Barramundi is caught mainly using gillnets in two Queensland-managed fisheries operating off the eastern and Gulf coasts.

A program of scientific assessment and modernised management arrangements for the fishery has recently been introduced, which is welcome. There are several populations or stocks of barramundi that are fished around northeastern QLD and the Gulf of Carpentaria. The scientific assessment shows that stocks are broadly healthy but there are some concerning signs in some stocks, including the major Gulf of Carpentaria stock, where egg production appears low. This may have consequences for the future sustainability of the fishery.

In both fisheries a number of threatened species are caught as bycatch, including green, loggerhead, and flatback turtles, inshore dolphins, dugongs, sawfish and a number of shark species, including hammerhead sharks. Even low levels of snubfin and humpback dolphin deaths will have a significant impact on their populations in QLD, and it is highly likely that fishing activity is resulting in the decline of populations in some areas.

In the Gulf of Carpentaria fishery a key secondary species that is caught in barramundi nets, king threadfin, has been dangerously overfished.

Fisheries managers in QLD have also reported inconsistencies between fisheries logbook records and information from independent observers, including differences between the number, rate and type of protected species interactions. There is a high probability that protected species bycatch is higher than reported.

Sectors of both fisheries also target some shark species, despite a lack of information on their stock status. There is limited information on much of the basic biology of many of the targeted species, e.g. their age at maturity, frequency of reproduction and number of young. This lack of knowledge is particularly concerning as shark species are generally long-lived, slow to mature and produce few young, making them highly vulnerable to population depletion as a result of fishing activity. Sharks are also apex predators that are essential to maintaining healthy marine food webs.

Independent fishery observer programs are an important method of verifying protected species interactions. Unfortunately the QLD Government closed the observer program for all QLD managed fisheries in 2012. Since that time there remains no independent on-vessel monitoring of the fishery’s impact, which is unacceptable for fisheries operating in the ecologically sensitive regions of the Great Barrier Reef and the Gulf of Carpentaria. In addition, for fisheries that interact with threatened species, there is no record of actual protected species interactions over time, the ecological impacts of the fishery cannot be measured or managed but these these fisheries are considered to pose a high risk to a range of threatened and vulnerable species.

While significant and laudable management reforms have been implemented in the east coast fishery; there has been insufficient action at time of writing to deliver improved environmental outcomes, particularly for threatened and protected species. Rankings in this fishery may be expected to improve in future. The Gulf of Carpentaria coast fishery continues to feature rudimentary and retrograde management arrangements and poses a significant threat to both target and bycatch species.