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- Western king prawns are caught using bottom otter trawl fishing methods in WA, SA and QLD, with most WA catch coming from fisheries in Shark bay and Exmouth Gulf.
- Western king prawn populations appear healthy though the major Shark Bay fishery has been impacted by environmental factors following a 2011 marine heatwave.
- Western king prawns are caught using otter trawls that operate on the seabed. Trawling is conducted over sandy and muddy habitats, and some protection for vulnerable habitats is provided by marine parks and closed areas.
- Bycatch reduction measures are mandatory in these fisheries, and have reduced accidental turtle catches. All fisheries interact with threatened species, including critically endangered species of sawfish, sea snakes and pipefish. There is some concern on the impact of these fisheries on sea snake populations.
- WA Shark Bay Prawn Managed Fishery, Exmouth Gulf Prawn Managed Fishery (953t in 2021)
Western king prawns are found throughout the Indo-West Pacific, and are fished around Australia except in southeastern waters. Western king prawn are found from inshore coastal waters to about 80m depth. The major WA fishery operates in Shark Bay, with smaller catches coming from a fishery operating in Exmouth Gulf. Both fisheries use bottom otter trawl fishing methods to target both tiger and western king prawns.
In the major fishery, operating in Shark Bay, there are minor concerns for the health of populations, where catches have been significantly lower in recent years than historical levels. This appears to be largely driven by environmental factors, including the loss of seagrass nursery habitat following a marine heatwave in 2011. Managers have responded proactively, and there is low risk of overfishing occurring. In the smaller Exmouth Gulf Prawn Fishery, western king prawn populations are in healthy condition.
In WA, a large and welcome proportion of the Shark Bay fishery is protected from the impacts of trawling in marine parks, with marine parks providing little such protection in the Exmouth Gulf fishery. Additional areas are closed to fishing for the purposes of preventing overfishing of juvenile prawns and damage to nursery habitats.
Bycatch reduction devices (BRD) and Turtle Exclusion Devices (TEDs) reduce the amount of threatened and other species that are caught and killed in fishing gear. BRDs and TEDs are mandatory in these fisheries and have been successful in reducing turtle deaths. However, threatened species bycatch remains an ongoing issue.
There are some concerns that bycatch management plans, including the requirement for independent studies of fishery impacts on bycatch species to be conducted every 3 years, are not being conducted in a timely manner. The annual scale (quantities) of bycatch and discarding, and the fate of many discarded species remain poorly understood.
The Shark Bay and Exmouth Gulf western king prawn fisheries catch two species of sea snake that are of particular conservation concern, and while the level of threat posed by prawn trawling is not clear, better management and monitoring of sea snake bycatch will be required in future in order to prevent a downgrade of these fisheries’ GoodFish ranking.