Line fishing in the Great Barrier Reef

Coral reef fish are caught by hook and line along the length of the Great Barrier Reef from the Torres Strait south to Fraser Island. More than 120 fish species are caught in the commercial line fishery, although only a few of them are actively targeted by commercial fishers. The high-value target species include coral trout, red throat emperor, red emperor, tropical snapper and Spanish mackerel.

Recreational anglers also target these species, particularly highly prized trophy species such as Spanish mackerel, red emperor and coral trout.

Research on the biology of fish species and the impacts of fishing is helping managers balance the needs of users while maintaining reef fish stocks and the reef ecosystem for future generations.

Commercial line fishing

Coral trout makes up 40-45 per cent of the commercial harvest of about 4400 tonnes of fish. Commercial fishers must have a licence to catch and sell fish and the number of commercial licences is capped in an attempt to reduce the potential for overfishing.

Most commercial line fishing operators work from large fishing vessels and then fish from smaller boats known as dories, which give them much greater manoevrability near the reef. Fish not destined for the live market are killed and off-loaded to the main boat where they are snap frozen or chilled. Fish destined for live export are kept in flow-through seawater tanks.

Nearly half the entire coral trout catch is exported as live food fish to overseas markets in Hong Kong and Southeast Asia. Although it is a valuable market, there is concern that this industry could lead to unsustainable levels of fishing effort and localised depletion of fish stocks.

Recreational fishing

Recreational fishing surveys indicate that there are more than 800,000 recreational fishers in Queensland, who spend more than $240 million each year to catch between 3500 and 4300 tonnes of seafood. As well, fishing is a popular activity for tourists, with about 120 charter fishing vessels operating in the Great Barrier Reef Marine Park. Recreational fishers catch mostly coral trout, red throat emperor, sweetlip and tropical snappers

Indigenous fishing

For centuries, traditional owners of sea country have managed fishing and collecting through customary law and traditions. Subsistence fishing is still an important cultural lifestyle activity for Indigenous people and is connected to traditional responsibilities of land and sea management. Special fisheries and marine park management arrangements are provided for traditional owners and other Indigenous Australians. For example, traditional fishing is not subject to fish size and bag limits.

Managing line fishing on the GBR

A system of zones is used in the GBRMP to protect critical habitats and manage human use including fishing. The Queensland Department of Primary Industries and Fisheries imposes limits on the size of fish allowed to be kept by all fishers and limits on the number of fish that can be kept by recreational and charter fishers.

In July 2004, GBRMPA implemented a new zoning plan for the GBRMP, increasing no-take areas from five per cent to 33 per cent of the total park area.

No-take areas can protect important fish breeding and nursery areas such as seagrass beds, mangrove communities, deepwater shoals and reefs. Scientific research in the Great Barrier Reef and elsewhere shows the benefits for many species when eggs, larvae and young fish develop unhindered in protected areas. As the size of fish increase within no-take areas, bigger fish produce more offspring. These fish can move into adjoining areas, effectively creating a ‘spill-over’ effect that helps replenish fish stocks in areas where fishing is allowed.

Setting minimum size limits is another management tool, in this case to protect fish from being caught until they have spawned at least once. The lifecycles of tropical fish are quite complex as many reef fish change sex during their lives in response to genetic or environmental factors. Managers need a detailed understanding of the biology of fish species to set the most appropriate size limits. Researchers funded by the Australian Governments Marine and Tropical Sciences Research Facility are studying the breeding and growth of target and non-target fish species to gather this information.