Conservation ActionsThrough proposals made in 2007 and 2013, all five sawfish species are now listed on Appendix I of the Convention on International Trade of Endangered Species (CITES), which essentially bans commercial international trade in sawfishes and their parts. In 2014, all sawfishes were added to Appendix I and II of the Convention on Migratory Species (CMS), which obligates Parties to act nationally and cooperate regionally to “strictly protect” the species. All sawfishes were added to Annex 1 of the CMS Memorandum of Understanding (MoU), which aims to facilitate regional conservation of the species.
Despite these binding international treaty mandates, sawfishes remain inadequately protected in a great number of countries where basic regulations are lacking and/or poorly enforced. A 2018 analysis identified the western Indian Ocean and Australasia among priority regions for concerted, international sawfish conservation policy action (Fordham et al. 2018). Yan et al. (2021) underscored the urgent need for domestic sawfish protections, particularly by nations where sawfish presence is uncertain, low or declining, yet extinction probability is low. Countries where sawfish are still regularly found that fail to apply species-specific prohibitions on killing, retention, sale, and trade (i.e., Papua New Guinea) are also considered priorities for conservation action.
Other potential Green Sawfish range states that still lack national protections include Somalia, Eritrea, Saudi Arabia, Iran, and Papua New Guinea (PNG) (Harrison and Dulvy 2014, Fordham et al. 2018, Lawson and Fordham 2018). There are concerns that in PNG, sawfish fins, including Green Sawfish, are being traded internationally which is in contravention of Papua New Guinea’s obligations as a party to CITES.
Australia, where Green Sawfish are still present and relatively well protected, is considered a “lifeboat” country, but relaxation of key safeguards would immediately threaten the species. Other countries with domestic protection for Green Sawfish include Bahrain, India, Bangladesh, and Indonesia (Harrison and Dulvy 2014, Fordham et al. 2018).
The Green Sawfish is protected by national legislation in Australia (Environmental Protection and Biodiversity Conservation EPBC Act, 1999; listed as Vulnerable in 2009) and state and territory legislation. In all state and territory waters mandatory reporting of threatened species including Green Sawfish interactions are required, although compliance is generally poor (Tillett et al. 2012). Several spatial protections are in place within Australia that likely benefit the Green Sawfish. These include networks of marine protected areas established by state and federal governments as well as fisheries closures such as prohibitions on trawling (e.g., Gaughan and Santoro 2021).
In addition to species-specific legal protections, sawfish recovery requires minimization of bycatch (and associated mortality) as well as conservation of important coastal habitats (Harrison and Dulvy 2014, Fordham et al. 2018). Effective enforcement of such safeguards requires ongoing educational initiatives, training (including in the area of species identification), and other capacity-building efforts. In these areas, there is room for improvement in every sawfish range state. Better monitoring of sawfish catches, including in artisanal fisheries, and expanded research programs are also needed to help understand population trends and inform management. The multi-lateral environmental agreements that have already listed sawfishes as species warranting strict protections can provide valuable platforms for facilitating sawfish recovery at regional and global scales, but targeted initiatives to do so have not yet been developed. This inaction demonstrates that ongoing public, political, and financial support is also integral to preventing further sawfish extinction.
Location InformationThe Green Sawfish has an Indo-Pacific distribution, occurring in tropical and subtropical waters, and it may be the most cold-water tolerant of the sawfishes. The species formerly occurred in the southwest Indian Ocean where it is now ‘possibly extinct’, with the last confirmed sighting from South Africa in 1991 (Everett et al. 2015). Their historical presence along the east Africa mainland (Mozambique, Tanzania, and Kenya) is unclear and recent studies have failed to find evidence of Green Sawfish having occurred there (Faria 2007, Leeney 2017, Braulik et al. 2020, G. Braulik unpubl. data 2022). Nonetheless, given its distribution elsewhere in the northern Indian Ocean it is thought the species was formerly distributed throughout the region (Yan et al. 2021).
Green Sawfish was formerly widespread throughout the northwest Indian Ocean and continuously distributed from Somalia to India, occurring throughout the Red Sea, Gulf of Aden, the Persian/Arabian Gulf, Gulf of Oman, and Arabian Sea (Harrison and Dulvy 2014, Moore 2015, Dulvy et al. 2016). Its current occurrence in much of this range is uncertain, partly due to a lack of reliable data, but it is now rare and restricted to a few areas. It is currently known to be extant in Eritrea, Sudan, Saudi Arabia (Red Sea), Oman, United Arab Emirates (UAE), Bahrain, and Iran (Dulvy et al. 2016, Jabado et al. 2017, Elhassan 2018, Yan et al. 2021, J. Spaet unpubl. data 2021).
Historically, the species is reported from the Gulf of Mannar, throughout the Bay of Bengal and the Andaman Sea, including along the east coast of India, Bangladesh, Myanmar, and the Andaman Islands. A tissue sample from a market in Chittagong, Bangladesh is the only recent record of the species from this region (Haque and Das 2019). Presently, it is now considered to be ‘possibly extinct’ in Sri Lanka and most of its former Indian range, except for the Sunderbands and Andamans where, its presence is uncertain due to lack of surveys (Tyabji et al. 2020, Tanna et al. 2021, K.V. Akhilesh unpubl. data 2022). Presence is uncertain in Myanmar (Yan et al. 2021).
The Green Sawfish was thought to have occurred throughout Southeast Asia including the Gulf of Thailand, Malay Peninsula, Malay Archipelago, and the South China Sea (Compagno and Last 1999, van Oijen et al. 2007, Manjaji-Matsumoto et al. 2017, Yan et al. 2021). Records from the Philippines that were incorrectly identified as Smalltooth Sawfish (Pristis pectinata), a species found only in the Atlantic Ocean, were most likely this species (Simpfendorfer 2005). Presence is now uncertain across most of the region and the species is ‘possibly extinct’ in Thailand, Singapore, China, and the Philippines (Yan et al 2021) and Taiwan (H. Ho unpubl. data 2020). Between 2017 and 2018 there were two records from Indonesia on the islands of Borneo and Sulawesi (B. Simeon and Dharmadi unpubl. data 2022). Throughout Melanesia, contemporary records of the species are rare, owing to a lack of survey effort and fisheries catch data. It has recently been observed along the southern coast of Papua New Guinea mainland (White et al. 2017a, Grant et al. 2021a).
The Green Sawfish was formerly distributed throughout tropical and subtropical Australia, and occurred as a vagrant to southwestern and southern Australia. In Western Australia, the range of the species appears to be largely intact, and it occurs from Shark Bay north into and throughout Northern Territory waters and in the Queensland Gulf of Carpentaria. Formerly, it was present throughout Queensland east coast waters and New South Wales (NSW) south to Jervis Bay, although a range contraction has occurred with the last records from Yamba in 1972 and it ‘possibly extinct’ in NSW and southeast Queensland. In Queensland, records south of Cairns are now rare (Harry et al. 2011, Wueringer 2017) and the southernmost recent confirmed record is from Mackay in November 2020 (Parsons 2020).
Australia, Bahrain, Bangladesh, Eritrea, Indonesia, Iran, Islamic Republic of, Malaysia, Oman, Papua New Guinea, Qatar, Saudi Arabia, Sudan, Timor-Leste, United Arab Emirates
China, Kenya, Mozambique, Pakistan, Philippines, Singapore, South Africa, Sri Lanka, Taiwan, Province of China, Tanzania, United Republic of, Thailand
Population InformationGenetic data for this species are unavailable for the majority of its range. Within Australia, Green Sawfish have low to moderate genetic diversity, with genetic evidence of a population bottleneck (Phillips et al. 2017b). Individuals from Western Australia and the Gulf of Carpentaria form genetically distinct stocks, with the remnant east coast portion potentially also forming a distinct stock (Phillips et al. 2011, Phillips et al. 2017a). Evaluating population trends for Green Sawfish is difficult due to its long history of human exploitation which is poorly documented. While there are scattered historical records throughout most of the Indo-Pacific, there is clear evidence that some areas supported large Green Sawfish populations, notably the Arabian Sea, the Gulf of Aden, Red Sea, the Persian/Arabian Gulf, and northern Australia including the Northwest Shelf and Timor Sea.
In the southwest Indian Ocean, analysis of records from South Africa, where Green Sawfish were regularly caught by bather protection nets until the early 1990s, suggesting extinction likely occurred between 2002–2005 (Everett et al. 2015). Ongoing fishing pressure in the region and profound anthropogenic changes to the St. Lucia estuarine system, a key nursery area, are likely to prevent the species from re-establishing in this region (B. Everett unpubl. data 2021).
In the northwest Indian Ocean, Green Sawfish were formerly widespread and abundant in the Red Sea and Gulf of Aden. There is a long history of exploitation and trade of sawfishes from the region with historical reports of high abundance of Green Sawfish in Djibouti, Eritrea, Sudan, and Yemen (Moore 2015). Interviews with fishers and landing site surveys suggest widespread and ongoing population declines or disappearance of sawfishes, including Green Sawfish, throughout the region. In 2007, interviews with fishers in Eritrea, Sudan, and Yemen indicated that dramatic declines in sawfishes had occurred over the past 60 years (Spaet and Elhassan 2014). In Sudan specifically, sawfishes were considered common in estuaries in the region until the mid-1980s but are now only rarely encountered along the southern coast (Elhassan 2018). Sudan is the only country within the Red Sea where recruitment of Green Sawfish continues to be observed, suggestive of a viable population (I. Elhassan unpubl. data 2022). Off the west coast of Saudi Arabia, interviews with fishers point to major population declines occurring between 1960–1990 (Spaet and Elhassan 2014). Two Green Sawfish individuals from the Al Wajh Bank in 2019 are the only recent records from the east coast of Saudi Arabia (J. Spaet unpubl. data 2021).
Green Sawfish were similarly historically widespread and abundant throughout the Persian/Arabian Gulf and the northern Arabian Sea, where there has likewise been a long history of human use of sawfishes (Moore 2015). Absence from surveys and fisheries landings in much of its former range suggests major population declines have occurred in most, if not all, areas, and that the population is now at a small fraction of its historic abundance. For example, data submitted from Pakistan to the Food and Agriculture Organization of the United Nations (FAO 2016) indicates that landings of sawfishes (all species) peaked at 84 t in 1990 and have declined to <1 t since 1996 (Moore 2015). This species has not been seen in the past three decades in Pakistan (Moazzam and Osmany 2014) and was last recorded in 1986 (M. Moazzam pers. comm. 3 March 2022). In 2019, targeted eDNA surveys along the Pakistan coast (Indus Delta, Minai Hor, and Gwadar) did not record this species (M. Cooper unpubl. data 2022). The last reported records from Kuwait and Iraq date back to over 20 years, in 2000 and the 1990s, respectively. In the last decade, there have been rare confirmed photographic records of one Green Sawfish captured in Qatar in 2014, two captures from Bahrain (2012 and 2019), two records from Oman (2014 and 2018), four records from the UAE (2014, 2016, 2017, 2019), and one record from Iran (2016) (R.W. Jabado unpubl. data 2022). In the Persian/Arabian Gulf and all regional seas, the expansion of fishing, including for sharks and rays, coupled with habitat destruction has been the cause of population decline (Harrison and Dulvy 2014, Jabado and Spaet 2017, Jabado et al. 2018). Despite protection of sawfishes in some countries, fishing intensity remains high and ongoing and planned coastal development continues to threaten key estuarine and mangrove habitats.
Sawfishes were historically widespread and abundant from the northern Indian Ocean, including the east coast of India and the Bay of Bengal (Harrison and Dulvy 2014). While data on populations are limited and not species-specific, available information suggests they have disappeared from most of the region and are now largely confined to Bangladesh (Haque et al. 2020) and possibly the Sunderbans in India (K.V. Akhilesh unpubl. data 2022). Only one Green Sawfish has been reported from the region, suggesting the remaining population size is small (Haque and Das 2019). In Sri Lanka, interviews with 300 fishers found that prior knowledge of sawfish increased with the respondent’s age and 1992 was the median year sawfishes were last seen (Tanna et al. 2021). An extensive review of the status of sawfishes in India did not find any recent records of Green Sawfish (K. V. Akhilesh unpubl. data 2022). Extensive interviews and workshops at landing sites, artisanal fishery surveys, and an overview of historical records have all confirmed the decline of sawfishes in Bangladesh compared to historical records and a >50% range constriction (A. Haque unpubl. data 2022). The average annual sawfish encounter rate (observations and catches) in Bangladesh declined from 3.7 individuals using lifetime recall data (~22-years), to 1.5 using 5-year recall data, and further to 0.7 using 1-year recall data (Hossain et al. 2015). While data from Bangladesh are not species-specific, this decline would be expected to extend to Green Sawfish. In Myanmar, recent fisheries surveys conducted in 2016–2021 in Southern Rakhine State by the Wildlife Conservation Society did not report Green Sawfish, and most fishers indicated they had not seen sawfishes in the last five years (M. Mizrahi unpubl. data 2022). Targeted eDNA surveys in the Myeik Archipelago and Ayeyarwady Delta also did not record this species, though survey locations were limited (M. Cooper unpubl. data 2022). Landings data and interviews with fishers from the Andaman and Nicobar Islands indicates sawfishes are no longer present in this region (Tyabji et al. 2020, Z. Tyabji unpubl. data 2022). Intense fishing pressure throughout the region including ongoing high demand for sawfish products (e.g., Haque and Spaet 2021) are likely to continue to threaten remaining populations of all sawfishes in the region, including Green Sawfish.
There are scattered historical accounts of Green Sawfish throughout Southeast Asia. The limited data on populations indicates widespread declines or disappearance of sawfishes throughout most of the region. Vidthayanon (2002) states that sawfishes including Green Sawfish have “disappeared from the rivers and coasts of [Thailand] during the last 10 years”. In 2019, targeted eDNA surveys in Singapore and Vietnam did not record this species (M. Cooper unpubl. data 2022). Interviews conducted in Sabah, Malaysia suggested that sawfishes including Green Sawfish were abundant prior to the 1970s and declined sharply in the 1980s with no further records since 1996 (Manjaji-Matsumoto 2002, Manjaji-Matsumoto et al. 2017). Sawfishes are still regularly encountered in Papua New Guinea; however, the Green Sawfish has always been noted as comparatively rare from the country and only recorded from the south coast (White et al. 2017a, Grant et al. 2021a). In this region, 66% of fishers interviewed by Grant et al. (2021a) reported declines in sawfish during their lifetimes, with most interviewees attributing declines to increased fishing activity or habitat degradation (e.g., from local logging or mining activity).
In Australia, there are no data available on the Western Australia population trend of Green Sawfish, although reports of the species are still common as far south as Shark Bay. This region may be the last population stronghold for the species globally, with juveniles widely distributed in nearshore habitats including estuaries and mangrove creeks along the northwest coast and adults occurring throughout the Northwest Shelf. Pupping has been observed to occur in the Ashburton River estuary, a key nursery area, each year since 2011 (Morgan et al. 2015) and it is speculated that pupping is widespread along the northwest Australian coast (Morgan et al. 2011). Recent records support this and indicate that pupping still occurs at least as far south as the Gascoyne River estuary (A. Harry unpubl. data 2022) as well as within Exmouth Gulf (K. Lear and R. Bateman unpubl. data 2022), the Pilbara (B. Weuringer unpubl. data 2022), and in the Canning Bioregion (A. Harry unpubl. data 2022). Although sawfishes are protected within Western Australia and release is mandatory, they are still regularly taken as bycatch by commercial and recreational fisheries; 96 sawfish were reported from commercial fisheries in 2020, 58 of which were Green Sawfish (Newman et al. 2021). Historical and contemporary fishing, in particular trawl and gillnet fisheries, have likely reduced the population although the magnitude of reduction is unknown. While fishing is an ongoing threat, during the last 15 years there has been a decrease in effort in commercial fisheries that interact with Green Sawfish within Western Australia. During this time, there was an increase in the catch-per-unit-effort of Green Sawfish by the Pilbara Trawl Fishery that may be indicative of increasing abundance (A. Harry unpubl. data 2021).
There are no data available on the Green Sawfish population from the Northern Territory (NT) and Gulf of Carpentaria. Reports of Green Sawfish are still common throughout the region, including recent evidence of recruitment in Cobourg Peninsula (NT) (Davies et al. 2022) and northwest Cape York (Gulf of Carpentaria, Queensland) (B. Wueringer unpubl. data 2022). The species is caught as bycatch in several commercial fisheries operating throughout the region, in particular fish trawl, prawn trawl, and gillnet (Peverell 2005, Field et al. 2013). They are the second most common sawfish caught in the Northern Prawn Fishery, with 11 individuals reported in 2020 (Fry et al. 2018, Laird 2021). Intensive, historical gillnet and trawl fishing by foreign vessels in Australian waters also likely impacted populations of Green Sawfish across northwest Australia, although data from these fisheries are limited (Giles et al. 2004). Contemporary and historical catch of all sawfish species is poorly quantified, but trawl and gillnet fishing intensity have been higher than in Western Australia, so a larger decline in the population is inferred for the Northern Territory and Gulf of Carpentaria.
Off the east coast of Queensland, the Green Sawfish has undergone a northward range contraction from Jervis Bay to central Queensland (Harry et al. 2011). Data from the Queensland Shark Control Program for the east coast populations of sawfishes indicated substantial declines in sawfishes, including Green Sawfish, occurred between the 1980s and 1990s (Wueringer 2017). For example, catch rates of sawfishes in two areas, Townsville and Rockhampton, declined by 72% and 93% from the 1970s to 1990, respectively. Recent fishery-independent surveys for elasmobranchs along the Queensland east coast have not reported the species (e.g., Simpfendorfer et al. 2014) and New South Wales has listed the species as presumed extinct. Data from an ongoing citizen science sightings program indicates that on Queensland’s east coast, Green Sawfish are still present in the Mackay area, and north of Cairns (B. Wueringer unpubl. data 2022). High fishing pressure, in particular trawl and gillnet fisheries, along much of the Australian east coast coupled with extensive habitat modification around most estuaries south of Cairns, are the cause of population decline.
Most of the Green Sawfish’s range is subject to intense human pressure, particularly through generally unregulated and unmanaged fisheries, combined with habitat loss and degradation in critical habitats, resulting in the continual declines of remnant populations and ongoing threats. Western Australia may be the last global stronghold for the species. Overall, it is inferred that the Green Sawfish has undergone a >80% population reduction over the last three generation lengths (50 years) due to overexploitation, habitat degradation, and reductions in extent of occurrence.
ThreatsThe Green Sawfish is subject to intense fishing pressure that is poorly managed or unregulated across much of its range. The species is taken as bycatch in commercial and small-scale fisheries (inclusive of artisanal, cultural, and subsistence) with a variety of fishing gears including gillnet, trawl, and line. The toothed rostra of sawfish make them highly susceptible to entanglement particularly in gillnets and trawls. Fishing effort has increased over the past decades across most of the species’ range with the fin and meat trade driving increasing demand and exploitation of many elasmobranchs (Chen 1996, Jabado et al. 2017, Okes and Sant 2019, Yan et al. 2021). In most instances throughout the range of this species, it is retained for at least its fins, rostra, and meat (CITES 2007, Yan et al. 2021). Within Australia and other jurisdictions where fishers are required to release sawfishes, at-vessel- and post-capture-mortality of captured sawfishes may still be high as individuals may be euthanized or have their rostrum removed in order to safely or efficiently untangle them from fishing gear (Morgan et al. 2016).
The inshore freshwater, estuarine, mangrove, and coastal habitats used by the species are threatened by habitat loss and degradation (CITES 2007). For example, in Southeast Asia, mangrove areas have been reduced by an estimated 30% since 1980 (Polidoro et al. 2010). For Green Sawfish, habitat loss or degradation is most concentrated on essential nearshore and estuarine nursery habitats. There may also be impacts on adult Green Sawfish associated with offshore oil and gas extraction (e.g., seismic surveys) which occurs in several areas within their range (e.g., the Australian Northwest Shelf, northwest Indian Ocean).
Historically, the northwest region of Australia has been relatively undeveloped and sparsely populated, and as a result has large areas of undisturbed coastal habitats. At present, there are several additional factors that may pose major threats to Green Sawfish in Western Australia (WA). These include a range of coastal developments, including various mining and natural resource operations which have export facilities along the WA coastline (Devillers et al. 2015). These include oil and gas and mining operations that have export facilities along the coastline, as well as substantial salt mining operations with seawater intakes and outtakes and export facilities. These operations include coastal developments such as lighted jetties, dredged shipping channels, and offloading structures with sea walls. For juvenile Green Sawfish using this area, tracking data suggests that such structures may hinder small juveniles from moving along the coastline (K. Lear and D. Morgan unpubl. data 2022), and therefore the increased numbers of these structures appearing in WA could cause some population fragmentation or destruction of important juvenile habitats for this species.