Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Listed as Vulnerable
Listing and Conservation Advices Listing Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008ny) [Listing Advice].
 
Approved Conservation Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008nz) [Conservation Advice].
 
Recovery Plan Decision Recovery Plan required, preferably as part of a multispecies Recovery Plan (16/02/2008).
 
Adopted/Made Recovery Plans
Policy Statements and Guidelines Survey guidelines for Australia's threatened fish. EPBC Act survey guidelines 6.4 (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2011i) [Admin Guideline].
 
Marine bioregional plan for the North Marine Region (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012x) [Admin Guideline].
 
Marine bioregional plan for the North-west Marine Region (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012y) [Admin Guideline].
 
Sawfish - A Vulnerability Assessment for the Great Barrier Reef (Great Barrier Reef Marine Park Authority (GBRMPA), 2011e) [Admin Guideline].
 
Sharks and rays - A Vulnerability Assessment for the Great Barrier Reef (Great Barrier Reef Marine Park Authority (GBRMPA), 2011j) [Admin Guideline].
 
Federal Register of
    Legislative Instruments
Inclusion of species in the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (61) (16/02/2008) (Commonwealth of Australia, 2008p) [Legislative Instrument].
 
State Government
    Documents and Websites
NSW:Species presumed extinct - green sawfish (NSW Department of Primary Industries, 2005b) [Internet].
NT:Threatened Species of the Northern Territory - Green Sawfish Pristis zijsron (Stirrat, S., H. Larson & J. Woinarski, 2006) [Information Sheet].
State Listing Status
NSW: Listed as Presumed extinct (Fisheries Management Act 1994 (New South Wales): August 2013)
WA: Listed as Vulnerable (Wildlife Conservation Act 1950 (Western Australia): September 2013)
Non-statutory Listing Status
IUCN: Listed as Critically Endangered (IUCN Red List of Threatened Species: 2011.2)
NT: Listed as Vulnerable (Indicative Conservation Status of Fish in the Northern Territory)
Scientific name Pristis zijsron [68442]
Family Pristidae:Rajiformes:Chondrichthyes:Chordata:Animalia
Species author Bleeker, 1851
Infraspecies author  
Reference  
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Illustrations Google Images
http://www.fishbase.org/Photos/ThumbnailsSummary.cfm?ID=7956

Scientific Name: Pristis zijsron

Common Name: Green Sawfish

Other Names: Narrowsnout Sawfish, Dindagubba

Pristis zysron is an older form of spelling for Pristis zijsron (Pogonoski et al. 2002)

The genus Pristis is taxonomically chaotic with uncertainty regarding the true number of valid species (Compagno & Cook 1995). The practical difficulties associated with resolving these taxonomic issues are acute, since it is extremely difficult to obtain specimens or tissue samples from these increasingly rare species for taxonomic research. P. zijsron is a member of the 'Pristis pectinata complex', probably also containing P. clavata, with narrow-based, less tapered, lighter rostral saws, with more numerous (usually over 23), smaller teeth than species of the Pristis pristis complex.

Pristis zijsron is a conventionally accepted species (Last & Stevens 1994).

Green Sawfish is a species of large ray from the family Pristidae. Green Sawfish have a shark-like body, a flattened head and an elongated snout or rostrum, which is studded with 24–28 pairs of unevenly-spaced rostral teeth. This tooth-studded rostrum is commonly described as the 'saw'. The first dorsal fin origin is slightly behind the pelvic fin origin and the lower lobe of the caudal fin is much shorter than half the length of the upper lobe. Green Sawfish are greenish brown or olive in colour on their upper surfaces and pale to white on their undersides. Mature adult Green Sawfish can grow to 5 m in length in Australian waters (Last & Stevens 1994; TSSC 2008ny, 2008nz).

In Australian waters, Green Sawfish have historically been recorded in the coastal waters off Broome, Western Australia, around northern Australia and down the east coast as far as Jervis Bay, NSW (Stevens et al. 2005).

Records indicate that the Green Sawfish occurred along the east coast of Queensland and NSW prior to the 1960s, however, after this period there have been no reports of this species south of Cairns. Data available from the Queensland Shark Control Program indicates a total disappearance of all sawfish in recent times in southern regions. This data represents a continuous sampling effort at the same locations throughout the year for over 40 years and provide the best long term dataset available for pristids (Stevens et al. 2005).

Previously in NSW, the species was regularly found in the shallow waters at the mouth of the Tweed, Clarence and Richmond Rivers, however the last recorded museum specimen from NSW was captured in 1972. The last specimen from the Sydney region was captured in 1926. With the Green Sawfish no longer found in NSW waters, or southern Queensland waters, the species appears to have experienced a contraction of range of around 30% in Australian waters (Stevens et al. 2005).

Little is known about their historical distribution in Western Australia and the Northern Territory, although given these areas are less populated than the east coast, it is likely that sawfish have not undergone declines of the same magnitude (Stevens et al. 2005).

The Green Sawfish is most commonly known from the Gulf of Carpentaria, Queensland (Stevens et al. 2005). Catch records show that the Green Sawfish inhabits all regions of the Gulf of Carpentaria, with a pattern of relative abundance, that is, in low numbers and with a highly variable frequency of occurrence (Peverell 2005). Within the Gulf of Carpentaria, Green Sawfish have been encountered in the Mission River and at Albatross Bay (Thorburn et al. 2004).

The Green Sawfish was once widely distributed in the northern Indian Ocean, westwards to South Africa, around South and South East Asia and around northern Australia. Available catch records suggest that the species may now be virtually extinct in South East Asia, and that northern Australia may be the last region where significant populations of Green Sawfish exist (Stevens et al. 2005).

From interviews carried out with communities on the Kinabatangan River and in Labuk Bay in Sabah, Borneo, villagers indicated a downward trend in Green Sawfish captures. They remembered them as abundant in the 1970s, declining sharply in the 1980s and almost impossible to catch since then (Manjaji 2002).

The Green Sawfish has not been recorded within fish markets of eastern Indonesia during searches for the Sharks and Rays of eastern Indonesia projects, despite over 160 visits to 11 markets from Jakarta to Kupang (CSIRO Marine Research n.d., cited in Stevens et al. 2005).

Pristid fins are highly sought after in the international shark fin trade (Rose & McLoughlin 2001), and escalating prices in this trade are cause for grave concern to all species in this family. Within the Indo-West Pacific, anecdotal reports suggest sawfish populations have declined drastically in the last 15–20 years due to this industry (CSIRO Marine Research, unpublished report, cited in Stevens et al. 2005).

No quantitative data is available on global population size of the Green Sawfish. There is a distinct lack of data on the biology of Pristis spp. with important parameters such as age and size at maturity, reproductive periodicity and lifespan being largely unknown (Stevens et al. 2005).

In view of the restricted movements of pristids, it is probable that the Australian population can be considered geographically separate, certainly in a management sense. There is almost certainly some genetic exchange with South East Asian populations, but this would only require movement of one or two individuals per generation to result in genetic homogeneity (Stevens et al. 2005).

The Green Sawfish was among a number of elasmobranchs surveyed in northern Australia to determine their regional status and to assess their distribution in rivers and estuaries across the north, spatial occupancy in each catchment and relative abundance in particular river systems (Thorburn et al. 2004).

Thorburn and colleagues (2004) carried out a broad, field-based survey of freshwater elasmobranchs in northern Australia. In six months of field work, they surveyed 137 sites within 39 river/creek systems in Western Australia, the Northern Territory and Queensland covering some 30 000 km during the project. Thorburn and colleagues (2004) caught only three Green Sawfish. Although fishing effort was directed more towards rivers and estuaries, it does indicate that the Green Sawfish is not abundant across the north. By comparison, this survey caught 16 Dwarf Sawfish (P. clavata), 17 Freshwater Sawfish (P. microdon) and two Narrow Sawfish (Anoxypristis cuspidate) (Stevens et al. 2005).

Due to the conservation and management concerns about the potential overlap in range of sawfishes (including the Green Sawfish) and the commercial fisheries, Feild and colleagues (2008) surveyed these interactions and published their findings in the Distribution and abundance of Glyphis and sawfishes in northern Australia and their potential interactions with commercial fisheries.

There is no data available on the abundance of Green Sawfish in Australian waters prior to European fishing. The species was historically described as the most commonly encountered sawfish in the Australian region and was regarded as a menace by net fishers on the east coast of Queensland due to the frequency with which Green Sawfish became entangled in and damaged nets (Pogonoski et al. 2002).

An increase in commercial net fishing and recreational fishing, in the 1960s and 1970s, corresponded with a widespread decline in the species (Pogonoski et al. 2002). This was evidenced by declining catch and bycatch rates, despite continuous catch effort. Anecdotal reports from commercial, recreational and Indigenous fishers concur that the species has been caught and observed less frequently over the last 30 years on the east coast of Australia (Pogonoski et al. 2002).

Sawfish bycatch from the Queensland Shark Control Program provides a large dataset from approximately 30 years of beach meshing around major Queensland population centres during the summer months. While this data is not species-specific, it shows a clear decline in sawfish catch from 1970 to 1990, particularly in southern Queensland, over which period the catch effort was relatively constant (Stevens et al. 2005).

Catch data indicate that the distribution and population of Green Sawfish within the Gulf of Carpentaria is very patchy (Stevens et al. 2005). There is little data on the species' relative abundance in northern Western Australian waters, although given that this region is less populated by humans than the east coast, it may contain the healthiest populations of the species' in Australian waters (Stevens et al. 2005).

Any remaining populations on the east coast can be considered "near the edge of the species range" and as such are extremely important to maintain genetic diversity along the east coast. Mortality in all remaining populations in northern Australia also needs to be reduced in order to maintain genetic diversity within this region. Information on long term movements, as well as data on population genetic structure, is required to determine the status of the northern 'stock' (Stevens et al. 2005).

The Green Sawfish inhabits muddy bottom habitats and enters estuaries (Allen 1997; Stead 1963). It has been recorded in inshore marine waters, estuaries, river mouths, embankments and along sandy and muddy beaches (Peverell et al. 2004; Stevens et al. 2005; Thorburn et al. 2004). Stead (1963) reported that this species was frequently found in shallow water. Its habitat is heavily fished and often subject to pollution, habitat loss and degradation from coastal, riverine and catchment developments. Green Sawfish have been recorded in very shallow water (<1 m) to offshore trawl grounds in over 70 m of water (Stevens et al. 2005).

Smaller specimens (<2.5 m in length) are more common in foreshore and offshore coastal waters (Thorburn et al. 2004), as well as estuaries and river mouths at slightly reduced salinities, but do not venture into freshwater. Larger individuals (>2.5 m in length) are found in both inshore and offshore waters. Their apparent preference for shallow inshore waters as nursery areas increases the likelihood of interaction with inshore gillnets (Stevens et al. 2005).

During surveying for the Status of Freshwater and Estuarine Elasmobranchs in Northern Australia (Thorburn et al. 2004) three Green Sawfish were captured. Two were encountered over sand, while the other over fine silt. All sites at which the species was present were subject to tidal influence with high flow, and captures occurred in waters of 1.2–3 m depth. All three sites had sparse coverings of detritus and snags. Water chemistry at the sites where the Green Sawfish were encountered ranged from 34.2–35.1 ppt (Thorburn et al. 2004).

Information on the short term habitat usage of a 3.5 m female Green Sawfish tracked in Port Musgrave, Queensland was obtained by Peverell and Pillans (2004). Over 27 hours, the sawfish moved 28.7 km at an average speed of 28.4 m/min and was at all times within 200 m of the shoreline in very shallow water. Average water depth was 0.69 m. During the day, the sawfish was in slightly deeper water (0.84 m) compared to the night (0.48 m) indicating a diurnal shift in water depth. The preference for shallow water shown by the sawfish in this study and the fact that it moved parallel to the shoreline suggests they may occupy a relatively small area of available habitat that is concentrated in a narrow strip of water adjacent to the shoreline (Stevens et al. 2005).

In Queensland, the Green Sawfish has been found in the same areas as Freshwater Sawfish and Speartooth Shark (Glyphis glyphis) within Port Musgrave (Peverell n.d., pers. comm., cited in Stevens et al. 2005). In the Gulf of Carpentaria, the Green Sawfish has been recorded in the same areas as Freshwater Sawfish. It has been recorded in the Van Diemen Gulf area with Freshwater Sawfish, Speartooth Shark and Northern River Shark (Glyphis garricki). Within Joseph Bonaparte Gulf, it has been recorded with the Northern River Shark and the Freshwater Sawfish (Stevens et al. 2005).

While limited data is available on the life history of Green Sawfish, it is likely that they are long-lived, produce few pups and mature late in life (Stevens et al. 2005; Walker 1998). The Green Sawfish appears to reach 95% of its maximum length (508 cm) at approximately 24 years of age and size at maturity (from direct observation) in 9 years (Peverell, James Cook University, unpublished MSc thesis, cited in Stevens et al. 2005). Based on these estimates of age, generation length is likely to be about 16 years (Stevens et al. 2005). The low fecundity and late maturation of Green Sawfish render the species highly susceptible to anthropogenic mortality and limits the ability of the species to recover from threats such as overfishing (Stevens et al. 2005; Stobutzki el al. 2002).

Sawfish return seasonally to inshore coastal waters adjacent to the northern Australian region to breed and pup. The Commonwealth Scientific Industrial Research Organisation and Fisheries agencies in Western Australia, Northern Territory and Queensland have recorded pupping in January (R. McAuley 2003, pers. comm., cited in Peverell 2005).This very scant dataset suggests pupping may occur during the wet season (Peverell 2005).

Little is known about reproduction in Green Sawfish. As in other pristids, the reproductive mode is aplacental viviparity with lecithotropic nutrition of the embryos (energy reserves come from the egg). Pristids have some of the largest ova sizes in the Chondrichthyes. Litter size in other pristids is up to 20. At birth, the rostrum is well developed but soft and flexible, and covered by a firm membranous sheath to protect the mother from injury (Grant 1978; Stevens et al. 2005). Grant (1978) suggested that adult males of this species use their saws during mating battles, evident from the scars and gashes on the saws of collected specimens.

The sex ratio of male to female is 1:1 (Peverell 2005).

A male, captured as a juvenile, survived 35 years in captivity (Allen 1982; Cliff & Wilson 1994).

Sawfishes generally feed on shoaling fish such as mullet, which are stunned by sideswipes of the snout. Molluscs and small crustaceans are swept out of the sand and mud by the saw (Allen 1982; Cliff & Wilson 1994). In addition the Green Sawfish actively pursue schools of baitfish and prawns (Poganoski et al. 2002). One Green Sawfish, captured in a prawn trawl targeting Banana Prawns (Penaeus merguiensis) in Joseph Bonaparte Gulf, had a Banana Prawn and two 8 cm Leiognathus bindus in its stomach (Stevens et al. 2005).

Peverell and Pillans (2004) observed a 3.5 m female Green Sawfish slashing its rostrum from side to side in shallow water. Herrings (Nematalosa come) and Anchovy (Thryssa hamiltonii) were observed jumping out of the water during these episodes, presumably to escape from the sawfish (Stevens et al. 2005).

It is unknown whether there is migration into Australian waters of Green Sawfish adults or juveniles from populations outside Australia. Green Sawfish are found in Indonesian waters and it is possible that individuals may migrate between Australia and Indonesia, however it is probable that the Australian population can be considered geographically separate (Stevens et al. 2005).

A large adult Green Sawfish was acoustically tracked in Port Musgrave in 2004, data collected showed that it moved continuously during the 27 hours it was tagged and did not rest on the bottom. This active behaviour renders the species susceptible to capture in gillnets, as animals are more likely to encounter fishing gear if they are moving around an area as opposed to being inactive for long periods (Stevens et al. 2005).

Peverell (2005) notes that the Green Sawfish was not recorded in the Gulf of Carpentaria between February and April.

Green Sawfish are vulnerable to most types of fishing gear including nets (particularly gillnets and demersal trawls) and hooks (Stevens et al. 2005).

Sampling should include a range of habitats from the coastal marginal zone and lower reaches of sheltered estuaries and embayments. Although short (30 m by 2.5 m drop) monofilament gill net panels, of 10, 15 and 20 cm stretched mesh are often suitable in riverine habitats, longer nets with a deeper drop should be used in coastal environments and large estuaries. Net length should be as long as is practical (100–200 m) and should have a drop that ensures the net is in contact with the substrate at all times. Nets should be set over mud/sand or rubble bottom in suitable locations. Given the movement patterns of a Green Sawfish tracked in Port Musgrave (Peverell & Pillans 2004), nets should be set in shallow water close to the bank. Ideally nets should be set from the high water mark at right angles to the shoreline. Nets should be set in multiple habitats including areas close to mangroves, sandy and muddy beaches, tidal channels, mud flat drains and mouths of suitable rivers and creeks. Because of the relatively low abundance of Green Sawfish, gill net set-times may need to be spread over several days at any site. This requires the nets to be closely monitored to minimise stress and prevent the death of captured specimens. Another factor will be the amount of bycatch present; at sites with high bycatch, nets should be checked every hour. When nets are set overnight, only larger mesh sizes should be used to minimise bycatch (Stevens et al. 2005).

Longlines can also be used to capture Green Sawfish but are not as effective as gillnets. Longlines should consist of a mainline of 9 mm rope with ganglions of at least 200 kg monofilament and 4–6/0 tuna circle hooks. Tuna circle hooks should be used in preference to other hook designs as the chances of gut-hooking animals is much smaller (Cooke & Suski 2004; Stevens et al. 2005).

The Green Sawfish is easily identified by the pattern of rostral teeth. These are spaced at increasing intervals from the rostrum tip, with the longest separation at the junction of the rostrum with the head (Stevens et al. 2005).

Sawfish are generally very hard to observe in their natural habitat. During the tracking of a Green Sawfish in Port Musgrave (Peverell & Pillans 2004), the animal was only observed very briefly on a few occasions when the rostrum was seen breaking the surface. This was despite the fact that the float attached to the tag was observed on several occasions, and that the sawfish was in water less than 1 m deep for much of the track (Stevens et al. 2005).

Fishing pressure
The toothed rostrum of sawfish, combined with their active hunting behaviour, makes them highly susceptible to capture in all fisheries that utilise nets. Gillnet and trawl fisheries operate throughout the range of Green Sawfish and pose the greatest threat to the species in Australia (Stevens et al. 2005).

Bycatch, or incidental capture, of Green Sawfish is known to occur in both the Pilbara Trawl Fishery and the Northern Prawn Fishery. Studies of shark and ray bycatch in the Northern Prawn Fishery have identified the Green Sawfish as a species that is particularly susceptible to capture, based on the species' behaviour and habitat preferences. An estimated 73 Green Sawfish of unrecorded size are caught as bycatch in the fishery annually (Stobutzki et al. 2002). In 2005, the Pilbara Fish Trawl Fishery in Western Australia reported that 16 Green Sawfish were caught, of which 6 died. In 2006, 26 Green Sawfish were caught with 7 fatalities. Anecdotal reports suggest that most of these animals are killed before landing to prevent them from inflicting damage to the crew and equipment on board with their flailing rostrums (Stevens et al. 2005).

Green Sawfish are also caught as bycatch in various gillnet fisheries in estuaries and inshore areas in north-western and northern Australia, particularly in the Gulf of Carpentaria (Stevens et al. 2005). The mortality of the species following interactions with this fishery is unknown.

The increased demand for shark and shark products will place additional pressure on sawfish populations in remote areas. This is not restricted to the Australian shark fishery, but includes impacts by the escalating foreign shark fishing presence in the Gulf of Carpentaria and elsewhere in the north. Salini (n.d., pers. comm., CSIRO Marine Research, cited in Stevens et al. 2005) has Coastwatch data on illegal shark fishing vessels from 2001–04 which shows a significant increase in illegal shark fishing very close to Australia. The arrest of 27 foreign vessels during this period, is clear evidence of this increase in shark fishing effort (Stevens et al. 2005).

The species is also caught by amateur fishers who sometimes kill the animals and remove the rostrum as a curio. Information on catch rates and post release mortality following capture by recreational fishers is unknown (TSSC 2008ny). In Australia, sawfish are known as a target sport fish and landings of sawfish have been recorded in recreational fishing competitions (Peverell 2005).

Recreational catch of sawfish is very difficult to quantify, the emphasis necessarily focusing on available anecdotal evidence. Rostra mounted on the walls of fishers' homes and in public establishments are testament to a long history of catch in northern Australia, extending into the fairly recent period of history before fishing licences and gear restrictions were introduced in Australia's north. An attempt was made to gather any available data and/or rostra dimensions from fishing clubs where sawfish are known to occur, and data sourced from previous research on recreational fisheries. Records in museum collections are often originally from the recreational sector (Stevens et al. 2005).

Shark finning
The Green Sawfish is targeted as a high value species in the shark fin trade. This trade has been identified as a primary threat to the species globally. Shark fins (including sawfish fins) exported to Asia can be worth $100-250/kg (Stevens et al. 2005). The fins of a large adult Green Sawfish are reported to be worth up to $2500. Shark finning is known to occur both legally and illegally in Australian waters. A secondary targeted threat to the Green Sawfish is the opportunistic trade in sawfish rostrums, which are used in traditional Asian medicines and sold as curios in Australia and overseas (TSSC 2008ny).

Habitat degradation
While there is little quantitative data, the number of sawfish appears to have declined drastically along the east coast of Australia over the last 40–60 years, with Green Sawfish now virtually extinct in NSW and south-east Queensland (Stevens et al. 2005). The disappearance of Green Sawfish from areas adjacent to dense human habitation suggests the species is sensitive to human disturbance. Habitat alteration and destruction caused by coastal development is likely to have a negative impact on the species, in particular disturbance to the inshore soft bottom areas they require for feeding and breeding (NSW DPI 2005; Stevens et al. 2005).

Australian Indigenous harvesting
The Australian Indigenous harvest of Green Sawfish is currently unknown, however it has been suggested that sawfish play a significant cultural and spiritual relevance to Indigenous Australians around the Gulf of Carpentaria (Peverell 2005).

Truelove (2003) provides information on the traditional utilisation of pristids, noting that they may represent a valuable, traditional source of food. Pristids have very high cultural and religious importance to some communities and there may be cultural restrictions on who can take them, limited to particular times and places. Some communities may use pristids as food for ceremonial purposes. Pristid rostra are used for ceremonial purposes by Indigenous peoples (Environment Australia 1998, cited in Stevens et al. 2005) and there are anecdotal reports that Indigenous peoples in the Weipa and Karumba area are buying sawfish rostra from commercial fishers. The rostra are then painted and the end product put onto the tourist market in Cairns (Truelove 2003).

Reproduction constraints
Green Sawfish are long lived, produce few young and mature late in life (Walker 1998). The low fecundity and late maturation of Green Sawfish render the species highly susceptible to anthropogenic mortality and limits the ability of the species to recover from other listed threats (Stevens et al. 2005; Stobutzki el al. 2002).

In response to information demonstrating that sawfish are at 'high risk' from commercial gillnetting, the Northern Territory Joint Authority Shark Fishery, has established a voluntarily 'no take' status for all sawfish, encouraging all commercial fishers to release them alive. Due to the difficulty in releasing large live sawfish, combined with the high value of their fins, it is uncertain whether this initiative will prove effective. The compliance of commercial operators is being assessed using log book data (McKee n.d., pers. comm., cited in Stevens et al. 2005).

Barramundi spawning closures in Queensland (1 November–1 February) and the Northern Territory (1 October–1 January) may offer some protection to Green Sawfish. These closures may offer short term protection to large females moving inshore to drop their pups, but at present there is insufficient data on sawfish life history to substantiate this. More data on habitat requirements and long-term movement patterns of Green Sawfish of all sizes is urgently required to determine adequate means of reducing incidental capture of this species in commercial fisheries (Stevens et al. 2005).

In the Northern Territory, commercial Barramundi gillnetting is prohibited from most major rivers where it has been replaced by recreational fishing (private anglers and charter operators). The Barramundi spawning closures apply to all fishers. The closure of most rivers to commercial gillnetting may have some benefits for Green Sawfish, however increased effort outside of rivers and estuaries will possibly negate these benefits. Again, data on movement patterns and habitat utilisation are required in order to assess the effectiveness of these spatial closures. The sub adult Green Sawfish tracked in Port Musgrave (Queensland) was captured outside of the estuary and outside of the temporal closure and was therefore not offered any protection by management regulations designed for other species (Stevens et al. 2005).

Western Australia has some spatial management of rivers and estuaries, however these are unlikely to influence the likelihood of sawfish capture (Stevens et al. 2005).

The NPF has a prohibition on the take of any elasmobranchs from prawn trawls. There is some evidence that Bycatch Reduction Devices (BRD) may reduce the capture of sawfishes. Survival of sawfish passing through a BRD is unknown, but this appears to be a significant issue in the NPF. The NPF has two major seasonal closures from approximately November–April and a mid-year closure for six weeks over July–August. The shortened fishing season, and reduction in number of vessels in the NPF are likely to result in an overall reduction in sawfish mortality. However, given historical effort and long generation time in sawfish, their populations will not have recovered from historical fishing levels and any additional mortality is a serious threat to their long term survival (Stevens et al. 2005).

The Commonwealth of Australia developed the National Policy on Fisheries Bycatch (DAFF 1999) and the Commonwealth Policy on Fisheries Bycatch (DAFF 2000). The National Policy on Fisheries Bycatch restricts its attention to non-target discard species and non-target organisms affected by fishing gear, and does not include byproduct species which include elasmobranchs (Stevens et al. 2005).

Turtle Exclusion Devices (TEDs) and BRDs have been trialled in the NPF since 1993 and became compulsory in this fishery in 2000. Trials to improve their performance through modifications are continuing. Projects are under way to evaluate the effectiveness of these devices, in collaboration with the fishing industry. A project by the Bureau of Rural Sciences, CSIRO and AFMA is monitoring the catch of sea turtles in the NPF. Results from these projects show that the use of TEDs and BRDs has resulted in a substantial decline in the catches of large animals such as turtles, stingrays and sharks. Sawfish are less likely to be effectively excluded by BRDs, however, some limited preliminary information suggests a 50% reduction in pristids (Brewer n.d., pers. comm., cited in Stevens et al. 2005).

The Commonwealth Government has provided funds from the Natural Heritage Trust to establish the SeaNet extension service. The project is focused on increasing the rate of adoption by the commercial fishing sector of new fishing gear and practices to aid bycatch reduction and to implement environmental best practice (Stevens et al. 2005).

The States and the Northern Territory have also been addressing bycatch. Western Australia and the Northern Territory have adopted the National Policy. Action plans, or management plans for fisheries, are being prepared in three States and the Northern Territory on a priority basis. The use of BRDs in two estuarine prawn trawl fisheries in New South Wales has been made mandatory, to save large quantities of juvenile fish. In Queensland, NSW and Western Australia, the recording of bycatch is currently being considered for compulsory inclusion in management plans (Stevens et al. 2005).

In addition, the Approved Conservation Advice for Pristis zijsron (Green Sawfish) (TSSC 2008nz) recommends the following priority actions:

  • Identify known sites of high conservation priority.
  • Protect remnants of the listed species through the development of conservation agreements and covenants with the fishing community.
  • Raise awareness of the species within the local, Indigenous and fishing communities, including species identification and handling techniques for bycatch specimens.
  • Improve reporting of interactions with commercial, recreational and Indigenous fishers.
  • Undertake research into the biology, ecology and threats to the species.
  • Work with fishers to develop appropriate codes of conduct for handling specimens to reduce incidental mortality.
  • Develop bycatch mitigation measures and gear technologies to reduce threats.
  • Assess the efficacy of current incidental threat abatement measures.
  • Mitigate Illegal Unreported Unregulated (IUU) fishing pressure on the species.

Marine bioregional plans have been developed for four of Australia's marine regions - South-west, North-west, North and Temperate East. Marine Bioregional Plans will help improve the way decisions are made under the EPBC Act, particularly in relation to the protection of marine biodiversity and the sustainable use of our oceans and their resources by our marine-based industries. Marine Bioregional Plans improve our understanding of Australia's oceans by presenting a consolidated picture of the biophysical characteristics and diversity of marine life. They describe the marine environment and conservation values of each marine region, set out broad biodiversity objectives, identify regional priorities and outline strategies and actions to address these priorities. Click here for more information about marine bioregional plans.

The Green Sawfish has been identified as a conservation value in the North-west (DSEWPaC 2012y) and North (DSEWPaC 2012x) marine regions. Maps of Biologically Important Areas have been developed for Green Sawfish in the North-west (DSEWPaC 2012y) Marine Region and may provide additional relevant information. Go to the conservation values atlas to view the locations of these Biologically Important Areas. The "species group report card - sharks and sawfishes" in the North-west (DSEWPaC 2012y) Marine Region and the "species group report card - sawfishes and river sharks" for the North (DSEWPaC 2012x) Marine Region provide additional information.

Documents relevant to the management and recovery of the Green Sawfish include the Approved Conservation Advice for Pristis zijsron (Green Sawfish) (TSSC 2008nz), the National Policy on Fisheries Bycatch (DAFF 1999), and the Commonwealth Policy on Fisheries Bycatch (DAFF 2000).

In addition the East Marine Bioregional Plan, Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the East Marine Region (DEWHA 2009m), the North-West Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North-West Marine Region (DEWHA 2008b) and the North Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North Marine Region (DEWHA 2008) also inform management of this species.

The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.

Threat Class Threatening Species References
Biological Resource Use:Fishing and Harvesting Aquatic Resources:Commercial harvest Listing Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008ny) [Listing Advice].
Biological Resource Use:Fishing and Harvesting Aquatic Resources:Harvest by gill netting Listing Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008ny) [Listing Advice].
Biological Resource Use:Fishing and Harvesting Aquatic Resources:Harvesting of shark body parts Listing Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008ny) [Listing Advice].
Biological Resource Use:Fishing and Harvesting Aquatic Resources:Illegal fishing practices and entanglement in set nets Listing Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008ny) [Listing Advice].
Biological Resource Use:Fishing and Harvesting Aquatic Resources:Illegal take Listing Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008ny) [Listing Advice].
Approved Conservation Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008nz) [Conservation Advice].
Biological Resource Use:Fishing and Harvesting Aquatic Resources:Incidental capture and death due to trawling fishing activities Listing Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008ny) [Listing Advice].
Biological Resource Use:Fishing and Harvesting Aquatic Resources:Mortality due to capture, entanglement/drowning in nets and fishing lines Listing Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008ny) [Listing Advice].
Approved Conservation Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008nz) [Conservation Advice].
Climate Change and Severe Weather:Habitat Shifting and Alteration:Habitat loss, modification and/or degradation Listing Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008ny) [Listing Advice].
Climate Change and Severe Weather:Habitat Shifting and Alteration:Habitat modification, destruction and alteration due to changes in land use patterns Listing Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008ny) [Listing Advice].
Ecosystem/Community Stresses:Ecosystem/Community Stresses:Habitat loss/conversion/quality decline/degradation Approved Conservation Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008nz) [Conservation Advice].
Ecosystem/Community Stresses:Indirect Ecosystem Effects:Loss and/or fragmentation of habitat and/or subpopulations Listing Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008ny) [Listing Advice].
Species Stresses:Indirect Species Effects:Low fecundity, reproductive rate and/or poor recruitment Listing Advice for Pristis zijsron (Green Sawfish) (Threatened Species Scientific Committee (TSSC), 2008ny) [Listing Advice].

Allen, G.R. (1982). A Field Guide to Inland Fishes of Western Australia. Perth, Western Australia: University of Western Australia Press.

Allen, G.R. (1997). Marine Fishes of Tropical Australia and South-East Asia - A field guide for anglers and divers. Third Revised Edition. Perth, Western Australia: Western Australian Museum.

Cliff, G. & G. Wilson (1994). Natal Sharks Board's Guide to Sharks and other Marine Animals.

Compagno, L.J.V. & S.F. Cook (1995). The exploitation and conservation of freshwater elasmobranchs: status of taxa and prospects for the future. The biology of Freshwater elasmobranchs. The Journal of Aquariculture and Aquatic Science. 7:62-90.

Cooke, S.J. & C.D. Suski (2004). Are circle hooks an effective tool for conserving marine and freshwater recreational catch-and-release fisheries?. Aquatic Conservation. 14:299-326.

Department of Agriculture, Fisheries and Forestry (DAFF) (1999). The National Policy on Fisheries Bycatch. [Online]. Available from: http://www.daff.gov.au/__data/assets/pdf_file/0009/629424/national-bycatch-policy-1999.pdf.

Department of Agriculture, Fisheries and Forestry (DAFF) (2000). Commonwealth Policy on Fisheries Bycatch. [Online]. Available from: http://www.daff.gov.au/__data/assets/pdf_file/0016/5812/bycatch.pdf. [Accessed: 02-Jul-2009].

Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC) (2011i). Survey guidelines for Australia's threatened fish. EPBC Act survey guidelines 6.4 . [Online]. EPBC Act policy statement. Canberra, ACT: DSEWPAC. Available from: http://www.environment.gov.au/epbc/publications/threatened-fish.html.

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2008). The North Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North Marine Region. [Online]. Canberra: DEWHA. Available from: http://www.environment.gov.au/resource/north-marine-bioregional-plan-bioregional-profile-description-ecosystems-conservation.

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2008b). North-West Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North-West Marine Region. [Online]. Canberra: DEWHA. Available from: http://www.environment.gov.au/coasts/mbp/publications/north-west/bioregional-profile.html.

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2009m). The East Marine Bioregional Plan, Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the East Marine Region. [Online]. Available from: http://www.environment.gov.au/coasts/mbp/publications/east/pubs/bioregional-profile.pdf.

Field, I.C., R. Charters, R.C. Buckworth, M.G. Meekan & C.J.A. Bradshaw (2008). Distribution and abundance of Glyphis and sawfishes in northen Australia and their potential interactions with commercial fisheries : final report May 2008. [Online]. Canberra, ACT: Department of the Environment, Water, Heritage and the Arts. Available from: http://www.environment.gov.au/coasts/publications/glyphis-sawfish-distribution.html.

Grant, E.M. (1978). Guide to fishes. Brisbane, Queensland: Department of Harbours and Marine.

Last, P.R. & J.D. Stevens (1994). Sharks and Rays of Australia. Melbourne, Victoria: CSIRO.

Manjaji, B.M. (2002). New records of elasmobranch species from Sabah. In: Fowler, S.L., T.M. Reed & F.A. Dipper, eds. Elasmobranch Biodiversity, Conservation and Management: Proceedings of the International Seminar and Workshop, Sabah, Malaysia. Page(s) 70-77.

NSW Department of Primary Industries (NSW DPI) (2005). Primefacts, Threatened Species in NSW: Green Sawfish - Pristis zijsron. [Online]. Port Stevens, N.S.W: Threatened Species Unit, Department of Primary Industries. Available from: http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0018/5085/Primefact-7-Green-Sawfish.pdf.

Peverell, S. (2005). Distribution of Sawfishes (Pristidae) in the Queensland Gulf of Carpentaria, Australia - with notes on sawfish ecology. Environmental Biology of Fishes. 73:391-402.

Peverell, S., N. Gribble & H. Larson (2004). 'Sawfish'. In: National Oceans Office, Description of Key Species Groups in the Northern Planning Area. [Online]. Hobart, Tasmania: Commonwealth of Australia. Available from: http://www.environment.gov.au/coasts/mbp/publications/north/pubs/n-key-species.pdf.

Peverell, S.C. & R.D. Pillans (2004). Determining feasibility of acoustic tag attachment and documenting short-term movement in Pristis zijsron Bleeker, 1851. Report for the National Oceans Office. 18.

Pogonoski, J.J., D.A. Pollard & J.R. Paxton (2002). Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes. [Online]. Canberra, ACT: Environment Australia. Available from: http://www.environment.gov.au/coasts/publications/marine-fish-action/pubs/marine-fish.pdf.

Rose, C. & K. McLoughlin (2001). A Review of Shark Finning in Australian Fisheries. Final report to Fisheries Resources Research Fund. Canberra, ACT: Bureau of Rural Sciences. Department of Agriculture, Fisheries and Forestry-Australia.

Stead, D.G. (1963). Sharks and rays of Australian seas. Sydney, NSW: Angus and Robertson.

Stevens, J.D., R.D. Pillans & J. Salini (2005). Conservation Assessment of Glyphis sp. A (Speartooth Shark), Glyphis sp. C (Northern River Shark), Pristis microdon (Freshwater Sawfish) and Pristis zijsron (Green Sawfish). [Online]. Hobart, Tasmania: CSIRO Marine Research. Available from: http://www.environment.gov.au/coasts/publications/pubs/assessment-glyphis.pdf.

Stobutzki, I.C., J.M. Miller, D.S. Heales & D.T. Brewer (2002). Sustainability of Elasmobranches Caught as By-catch in a Tropical Prawn (Shrimp) Fishery. Fishery Bulletin. 100:800-821.

Thorburn, D.C., S. Peverell, S. Stevens, J.D. Last & A.J. Rowland (2004a). Status of Freshwater and Estuarine Elasmobranches in Northern Australia. Report to Natural Heritage Trust. [Online]. Canberra, ACT: Natural Heritage Trust. Available from: http://www.environment.gov.au/coasts/publications/elasmo-north.html. [Accessed: 04-Jul-2009].

Threatened Species Scientific Committee (TSSC) (2008ny). Listing Advice for Pristis zijsron (Green Sawfish). [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/68442-listing-advice.pdf.

Threatened Species Scientific Committee (TSSC) (2008nz). Approved Conservation Advice for Pristis zijsron (Green Sawfish). [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/68442-conservation-advice.pdf.

Truelove, K. (2003). Draft freshwater sawfish (Pristis microdon) Recovery Plan. Page(s) 51. Unpublished Report. Canberra, ACT: Department of the Environment and Heritage.

Walker, T.I. (1998). Can shark resources be harvested sustainably? A question revisited with a review of shark fisheries. Marine and Freshwater Research. 49:553-572.

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This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.

Citation: Department of the Environment (2014). Pristis zijsron in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Fri, 18 Apr 2014 13:35:37 +1000.