BMRG Coastal Forum 19 th April 2008

1. Green Sawfish Recovery Plan Project BMRG Coastal Forum 19th April 2008 Dr Ashley Bunce Centre for Environmental Management Central Queensland University

2. Sawfish • Sawfish are modified rays which have shark like bodies • Distinguished by a flattened head and a narrow blade-like snout armed with 24-28 pairs of lateral teeth • Also similar to and often confused with sawsharks (distinguished by presence of gills on the underside of head)

3. Australian Sawfish Species • There are 4 known sawfish species in Australian Waters • Narrow sawfish (Anoxypristis cuspidata) • Freshwater sawfish (Pristis microdon) • Green sawfish (Pristis Zijsron) • Dwarf sawfish (Pristis clavata) • These species occupy niches in marine estuarine and freshwater environments

5. Green Sawfish Taxonomy Order - PristiformesFamily - PristidaeGenus - PristisSpecies - zijsron Conservation Status IUCN Red List - Critically endangered; EPBC – vulnerable; QLD – ‘Back on Track’ priority species; NSW – critically endangered; NT Fisheries - vulnerable

6. Distribution and Habitat Very low numbers in waters of southern and central QLD More common in nth region (including the Gulf of Carpentaria) Live on muddy or sandy-mud soft bottom habitats Inhabit coastal foreshores and bays mostly as juveniles Inhabit marine waters to a depth greater than 40m as adults Adults known to seasonally frequent inshore waters and rivers during monsoonal months to pup

7. Description • Large slender body • Olive brown-green dorsally and pale white ventrally • Rostrum does not narrow at tip Descriptors • 24-28 pair of teeth • Teeth are moreclosely spaced at tip and extend onto base of saw • No fork in caudal fin • 1st dorsal fin begins behind pelvic fin origin • Rough skin Size • Maximum reported size 730cm Diet • Prawns and fish

8. Biology • Long-lived (25-30 years) • Gestation period (fertilisation to birth time) is approx. 5 months • Average of 8 pups are born at around 65-90cm • Pups born with a toothed rostrum which is covered by a enclosed membrane designed to protect mother from teeth

9. Behaviour • Use rostrum for feeding by • Stunning slow moving schooling fish with slashing motion • Locating and dislodging prey buried in sand or mud • Locate buried prey by using sensors on rostrum • Will also eat dead prey and strike at lures • Sawfish are nocturnal • Sleep in the day • Hunt at night • Sawfish are top order predators • Actively seek out prey items such as fish and crustaceans

10. Threats to Sawfish Conservation Status IUCN Red List - Critically endangered; EPBC – vulnerable; QLD – ‘Back on Track’ priority species; NSW – critically endangered; NT Fisheries - vulnerable Saw fish are threatened throughout the world All Australian species are on the IUCN Redlist of threatened species as critically endangered Because they prefer an inshore benthic habitat for breeding, the juveniles are vulnerable to human interference They are also known to actively seek out dead baits or strike at lures making them vulnerable to recreational fishing

11. Threats to Sawfish Major threats include • Accidental capture/Entanglement in fishing nets • Illegal fishing for fins or rostrums • Habitat degradation through coastal development

12. Entanglement in fishing nets • Sawfish are vulnerable to entanglement as the rostrum is easily entangled in nets and fishing line • The sawfish thrashes around to get free causing further tangling • When unable to swim the sawfish is unable to move water over gills and may drown • Entanglement may occur in • Trawling nets • Inshore net fishery • Recreational fishing (line and small mesh cast and seine nets)

13. Illegal Fishing • Sawfish are hunted for their • Rostrums • Fins • Flesh • Other body parts • These are sold for food and use in traditional Asian medicines • Rostrums are sold as valuable souvenirs, trophies or curios • Sawfish may also be collected as live specimens for aquariums

14. Habitat degradation through coastal development • Loss of soft bottom feeding and breeding habitats through coastal urban/industrial development Building of weirs and barrages can restrict movement of sawfish in rivers • Other problems include increased pollution from: • Use of fertilisers - increased nutrient runoff • Use of pesticides - reduced health and death of organisms

15. Green Sawfish Recovery Plan • Objectives - • Background on species and ecology • Distribution and location • Known and potential threats • Recovery Actions Other - Achieving multi-species outcomes that apply to estuarine stingray which occupy the same habitat

16. Distribution and location Once common along the east coast of Australia, and found as far south as Jervis Bay, is now rarely found south of Cairns Estuaries along east coast of central QLD almost certainly provided suitable habitat in the past No museum records from central QLD, last records from east coast from Moreton Bay in 1970s Spotted any Sawfish? Unconfirmed reports of sightings in the region as recently as 2004 Possible breeding area located near the mouth of the Fitzroy River

17. Supported by: For further information contact: Dr Ashley Bunce Centre for Environmental Management Central Queensland University Tel: 07 4970 7285 E-mail: a.bunce@cqu.edu.au