Freshwater sawfish
Providing sanctuary for freshwater sawfish in Queensland
With its saw-like snout and large size, the freshwater sawfish has been overfished and needs our support to survive in Queensland waters.
Fast facts
Common name: Freshwater sawfish
Scientific name: Pristis pristis
Family: Pristidae (sawfishes)
Status: Vulnerable (EPBC Act), Critically Endangered (IUCN)
Habitat: Mud bottoms of large rivers and estuaries in subtropical and tropical waters
Species overview
At up to 6.5m in length, the freshwater sawfish is the largest freshwater fish found in Australia. All 4 species of sawfish in Australia are among the world’s most endangered sharks and rays.
Some First Nations communities in northern Australia have strong cultural connections to sawfishes and for some coastal communities, sawfish are a traditional source of food.
Sawfish were once common along Queensland’s east coast, from the tip of Cape York to Brisbane. Today, they are found in the far north only. The 4 species in Queensland are:
- freshwater (largetooth) sawfish (Pristis pristis)
- green sawfish (Pristis zijsron)
- dwarf sawfish (Pristis clavata)
- narrow sawfish (Anoxypristis cuspidata).
Overfishing and habitat change combined with the freshwater sawfish’s slow breeding rate have caused significant population declines. Freshwater sawfish are particularly vulnerable because their reproductive and survival strategies depend on freshwater and estuarine water quality and availability.
Although freshwater sawfish are protected throughout Queensland, they risk being accidentally caught by fishers. Unfortunately, sometimes, people deliberately kill them for their rostrum (snout) or fins, which is illegal. Freshwater sawfish are also sometimes taken for display in aquariums through a highly regulated fishery.
Behaviour and ecology
The freshwater sawfish is a predator, using its saw-like rostrum for hunting and self-defence. The species feeds on fishes and benthic (bottom-living) invertebrates. Small sawfish are also sometimes taken by sharks and crocodiles.
Fine electromagnetic sensors along its rostrum help it detect prey. The receptors of the lateral line detect the prey’s movement. Sawfish use their rostrum to club and slash prey before eating it whole.
This species spends its first 3–4 years in estuaries and rivers, growing to about half its adult size (3m) before moving to coastal and offshore waters up to 25m deep.
They reach sexual maturity at 8–10 years. Female sawfish produce eggs, which male sperm fertilise in a duct connecting the ovary to the uterus. Like sharks, sawfish males have organs called ‘claspers’ to insert the sperm into the females.
Sawfish embryos grow attached to the eggs inside the mother. They are born alive at around 76cm in length, with their saws covered in a sheath to protect the mother.
Freshwater sawfish may reach a length of up to 100cm by their first birthday and 140cm by their second. Their growth slows as they mature.
Scientists believe the freshwater sawfish may live as long as 44 years.
Characteristics
The freshwater sawfish has:
- a flattened shape
- a long, flattened snout edged with teeth resembling a saw
- a length of up to 6.5m
- two prominent dorsal fins of almost equal height
- eyes positioned at the top of their head
- skin that resembles the sandpaper-like skin of sharks
- olive-brown colour above and white below
- gills underneath their body.
Threats
- Habitat degradation and modification
- Accidental bycatch from commercial and recreational fishing activities.
What’s being done?
- In partnership, we are reducing impacts on water quality and flow in freshwater habitats in North Queensland.
- We have established several closed areas for gillnet fishing along the east coast, including a gillnet-free zone in the far north of the Great Barrier Reef from Cape Bedford to the tip of Cape York. This zoning protects sawfish and other threatened marine species from the risks of gillnetting in those areas.
- Alongside agencies and fishers, we are working to reduce bycatch and improve the post-release survival of the freshwater sawfish.
Who is helping?
- Sharks And Rays Australia (SARA)
In partnership with Indigenous Land and Sea Rangers, SARA conducts sawfish research and monitoring in the Rinyirru (Lakefield) National Park (Cape York Peninsula Aboriginal Land) and other areas with Traditional Owners.
How you can help
- Remember that sawfish are a ‘no-take’ species.
- Report freshwater sawfish sightings to Report Your Sighting – Sharks And Rays Australia.
- Report sawfish injuries or deaths by calling 1300 130 372.
- If you accidentally catch any sawfish:
- leave the fish in the water, if possible, to avoid causing it undue stress
- use a dehooking device to remove the hook safely, or if this is impossible, cut the line as close to the hook as possible
- release the fish promptly and gently
- report the accidental catch by calling 1800 CY TAGS
- Make a donation to support Queensland threatened species protection and science and research-based initiatives.
- Find out more about how you can help support threatened species efforts.