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 as Natator depressus
Listed marine as Natator depressus
Listed migratory - Bonn as Natator depressus
Recovery Plan Decision Recovery Plan required, this species had a recovery plan in force at the time the legislation provided for the Minister to decide whether or not to have a recovery plan (19/2/2007).
 
Adopted/Made Recovery Plans Recovery Plan for Marine Turtles in Australia - July 2003 (Environment Australia (EA), 2003ai) [Recovery Plan] as Natator depressus.
 
Other EPBC Act Plans Threat abatement advice for predation, habitat degradation,competition and disease transmission by feral pigs (2013) (Commonwealth of Australia, 2014p) [Threat Abatement Plan].
 
Threat Abatement Plan for Predation by the European Red Fox (Department of the Environment, Water, Heritage and the Arts (DEWHA), 2008zzq) [Threat Abatement Plan].
 
Threat abatement plan for the impacts of marine debris on vertebrate marine life (Department of the Environment, Water, Heritage and the Arts (DEWHA), 2009t) [Threat Abatement Plan].
 
Policy Statements and Guidelines 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].
 
Seagrass - A Vulnerability Assessment for the Great Barrier Reef (Great Barrier Reef Marine Park Authority (GBRMPA), 2011k) [Admin Guideline].
 
Information Sheets Information Sheet - Harmful marine Debris (Environment Australia, 2003ac) [Information Sheet].
 
Federal Register of
    Legislative Instruments
Declaration under s178, s181, and s183 of the Environment Protection and Biodiversity Conservation Act 1999 - List of threatened species, List of threatened ecological communities and List of threatening processes (Commonwealth of Australia, 2000) [Legislative Instrument] as Natator depressus.
 
List of Migratory Species (13/07/2000) (Commonwealth of Australia, 2000b) [Legislative Instrument] as Natator depressus.
 
Declaration under section 248 of the Environment Protection and Biodiversity Conservation Act 1999 - List of Marine Species (Commonwealth of Australia, 2000c) [Legislative Instrument] as Natator depressus.
 
State Government
    Documents and Websites
NT:Threatened Species of the Northern Territory - Flatback Turtle Natator depressus (Taylor, R., R. Chatto & J. Woinarski, 2006b) [Information Sheet].
QLD:Flatback turtle (Department of Environment and Heritage Protection (DEHP), 2013u) [Database].
State Listing Status
QLD: Listed as Vulnerable (Nature Conservation Act 1992 (Queensland): May 2014 list) as Natator depressus
WA: Listed as Vulnerable (Wildlife Conservation Act 1950 (Western Australia): September 2013 list) as Natator depressus
Non-statutory Listing Status
IUCN: Listed as Data Deficient (Global Status: IUCN Red List of Threatened Species: 2013.1 list)
Scientific name Natator depressus [59257]
Family Cheloniidae:Testudines:Reptilia:Chordata:Animalia
Species author (Garman,1880)
Infraspecies author  
Reference  
Other names Natator depressa [25566]
Chelonia depressa [1764]
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.jcu.edu.au/school/tbiol/zoology/herp/fullsize/GC%20Natator%20depressus.jpg

Scientific Name: Natator depressus

Common Name: Flatback Turtle


No other names have been recently used but the species was previously known as either Chelonia depressus or Chelonia japonica (Limpus et al. 1988, Limpus 2007).

The Flatback Turtle has a low domed, fleshy carapace (shell) with reflexed margins and is grey, pale grey-green or olive in colour (Bustard 1972; Cogger 1996, 2000; Limpus 1971).

Adult females have a mean curved carapace length of 92 cm (Limpus 1971). Hatchlings are olive-green with dorsal scales outlined in black (Cogger 1994, 2000) and measure 6.1 cm in straight carapace length and weigh approximately 43 g (Limpus 1971) and are the largest hatchlings of marine turtles. The carapace and trailing edges of flippers have white margins. The ventral surfaces are completely white and the iris of the eye of the hatchling is blue (Limpus 1971, 2007).

The Flatback Turtle is found only in the tropical waters of northern Australia, Papua New Guinea and Irian Jaya (Spring 1982; Zangerl et al. 1988) and is one of only two species of sea turtle without a global distribution.

Nesting is confined to Australia and four genetic stocks are recognised (Limpus et al. 1981, 1983a; Limpus 2007).

Eastern Queensland
In eastern Queensland nesting occurs between Bundaberg in the south and northwards to Torres Strait. The main nesting sites occur in the southern Great Barrier Reef (GBR) at Peak, Wild Duck and Curtis Island (Limpus 1971; Limpus et al. 1981, 1983b). Minor nesting occurs at Mon Repos and the Mackay Region. Scattered aperiodic nesting occurs on mainland and inshore islands between Townsville and Torres Strait.

Torres Strait and Gulf of Carpentaria
In the Torres Strait and north-west Gulf of Carpentaria the major breeding rookeries include Crab, Deliverance and Kerr Islands and the mainland (Limpus et al. 1983b, 1989, 1993). Rookeries in the southern Gulf of Carpentaria include the Wellesley (Limpus 1995a) and Sir Edward Pellew Islands (Hamann et al. 2006).

Northern Territory
Flatback Turtles are the most widely spread nesting marine turtle species in the Northern Territory (Chatto & Baker 2008), nesting on a wide variety of beach types around the entire coastline. Through surveys held between 1994 and 2004, Chatto and Baker (2008) have identified 46 distinct areas within the Northern Territory that are confirmed (a total of 18), or inferred as highly likely to represent (28 sites), significant nesting areas for the Flatback Turtle. The majority of these sites are on islands. Arnhem Land rookeries include Cobourg Peninsula and Greenhill Island (Hope & Smit 1998), Field Island (Winderlich 1998; Schauble et al. 2006) and McCluer Island (Guinea 1990). West of Darwin, significant nesting occurs in Fog Bay, Northern Territory (Guinea & Whiting 1999). Other significant sites include Turtle Point, North Perron Island and the Tiwi Islands (Chatto 1998).

Western Australia
The Kimberley Region of Western Australia, Cape Dommett (Bowlay & Whiting 2007) and Lacrosse Island are important nesting areas. On the North-West Shelf, the major rookeries are on the mid-eastern coast of Barrow Island and at Mundabullangana Station near Cape Thouin on the mainland (Prince 1994a,b).

The current extent of occurrence is 3 570 106 km².

There is no data to indicate that there has been a decline in the extent of occurrence over the past three generations (Limpus 2007), nor is there sufficient empirical data to indicate future changes in the area of occupancy. However, changes to air and sea temperatures, sea level rise and other physical aspects that may change with global warming have the potential to alter the species occurrence (Hamann et al. 2007).

The major locations of Flatback Turtles include:

    Eastern Queensland
    Peak Island
    Wild Duck Island
    Curtis Island
    Avoid Island
    Mon Repos

    Torres Strait and Gulf of Carpentaria
    Crab Island
    Deliverance and Kerr Islands
    Mainland beaches of north western Cape York
    Welesley Island Group
    Sir Edward Pellew Islands
    Groote Eylandt

    Northern Territory (Chatto & Baker 2008)
    Turtle Point area
    North Perron Island
    Bare Sand Island
    Tiwi Bioregion (in particular Brenton Bay to Tinganuwu Bay and west end Bathurst Island)
    Green Hill Island
    Cobourg Peninsula bioregion (in particular North Goulburn Island)
    Arnhem Wessel bioregion (in particular North West Crocodile Island, Small Island and north-east end Ingliss Island)
    Groote Bioregion (in particular Bremer Island, Bremer Islet and Isle Woodah)

    Western Australia
    Cape Dommit and Lacrosse Island
    Mid-eastern coast of Barrow Island
    Mundabullangana Station near Cape Thouin on the mainland
    Cemetery Beach within the town of Port Hedland
    Bell's Beach near Wickham
    Eighty Mile Beach (the greatest concentrations in the Mandora-Wallal section).

No captive or propagated populations exist or have been released.

Flatback Turtles have a restricted distribution. It is one of only two marine turtles not having a global distribution. All recorded nesting beaches are in Australia (Limpus et al. 1989). The species feeds widely through the waters over the Australian continental shelf to as far north as the Gulf of Papua in Papua New Guinea (Spring 1982) and coastal waters of Papua in Indonesia. (Samertian & Noija 1994). Outside the Australian continental shelf, the species has been recorded from the coastal waters of Kei, eastern Indonesia (Suarez 2000).

The Flatback Turtle has been well surveyed for its nesting distribution but not for its foraging distribution.

In the GBR World Heritage Area (GBRWHA) all nesting sites have been identified and ranked for importance (Dobbs 2007). The area of coast between Gladstone and Hervey Bay has been routinely surveyed (at varying intervals) by Queensland's Parks and Wildlife Services (QPWS) since the early 1970s (Limpus 2007). Nesting trends at Mon Repos and Curtis Island show no signs of decline. Data for eastern Queensland would be accurate enough to identify future shifts in the species nesting occurrence. If nesting beach surveys are continued data would be accurate enough to detect changes to population size.

In the Gulf of Carpentaria the species nesting distribution (but not foraging distribution) has been well investigated, using both aerial and vehicle surveys (Chatto 1998; Hamann et al. 2006). QPWS, in cooperation with Traditional Owner groups, have also monitored the nesting beaches on the western Cape York. If continued, these surveys will provide valuable information on lesser known rookeries and populations. Overall, few data exist for the Gulf of Carpentaria population and population sizes and trends are thus unknown. Regardless, Limpus (2007) regards the Gulf of Carpentaria population to be in the early stages of decline (based on current and predicted level of threat).

In the Northern Territory (Cape Arnhem to the Bonepart Gulf (Western Australia)) the species has been well investigated, using both aerial and vehicle surveys, for its nesting distribution but not for its foraging distribution (Chatto 1998; Chatto & Baker 2008; Hamann et al. 2006; Schauble et al. 2006). Two index sites for the Northern Territory genetic stock have been surveyed to various degrees since the mid 1990s; Bare Sand (Guinea 1998) and Field Island (Schauble et al. 2006).

There were around 300 days of survey between 1991 and 2004 (Chatto & Baker 2008) along eight defined "bioregions" of the Northern Territory. These surveys recorded over 24 000 observations of coastal wildlife around 10 875 km of coastline. Over 1600 Flatback Turtle nests were recorded on island beaches compared to just under 200 nests on mainland beaches in these surveys (Chatto & Baker 2008). In the Arnhem Wessel bioregion, 433 nests were recorded during this period; on the islands associated with the Anson Beagle bioregion 456 nests were recorded and in the Tiwi bioregion some 313 nests were recorded (Chatto & Baker 2008).

In Western Australia the species has been reasonably well surveyed for its nesting distribution but not for its foraging distribution (Prince 1998). However, few published accounts of population data are available.

Most data from Flatback Turtle foraging distribution comes from fishery bycatch in the East Coast Trawl Fishery (Robins 1995).

There are no estimates of population size for the Flatback Turtle. However, they are currently being calculated as part of the IUCN Red List Assessment process. This process was due to be completed mid 2008.

Dutton and colleagues (2002) and Limpus (2007) identify four genetic stocks:

Eastern Australia
Centred on Peak, Wild Duck and Avoid Islands.

Torres Strait/Gulf of Carpentaria
North-eastern Gulf of Carpentaria and western Torres Strait (centred on Crab and Deliverance Islands)
Wellesley Group (centred on Bountiful Island)
Western Gulf of Carpentaria (centred on Sir Edward Pellew Islands, South-eastern Groote Eylandt area (four sites between Ilyungmadja Point and Ungwanba Point).
Sandy Islet.

Western Northern Territory
Cobourg Peninsula
Field Island
Quail Island
Bare Sand Island
The Cape Domett nesting population of Bonapart Gulf in Western Australia may be part of this stock.

Western Australia
North-West Shelf (from Exmouth to the Kimberley Coast)

The nesting rookeries on the eastern beaches of Barrow Island are a major part of the North-west shelf genetic stock. (Dutton et al. 2002). This summer breeding Pilbara Coast (Northwest Shelf) stock effectively will not interbreed with the neighbouring winter (mid year) breeding Flatback Turtle stock that aggregates to breed in western Arnhem Land and Bonepart Gulf (Limpus 2007).

The Eastern Australia stock appears to be stable and can be regarded as secure but conservation dependent (Limpus 2007).

Limpus (2007) regards the Gulf of Carpentaria population to be in the early stages of decline (based on current and predicted level of threat).

No population trend data exist for Western Australia.


Flatback Turtles have not been recorded breeding with other marine turtle species.

The eastern Australia stock is well protected (~70%) for both nesting and foraging by the GBRWHA and the Woongarra Marine Park (Limpus 2007).

Gulf of Carpentaria and Torres Strait - Deliverance and Kerr Islands are included in the Warul Kawa Indigenous Protected Area. All nesting sites are located on Indigenous owned land or located in very remote areas of coast isolated from current development.

Northern Territory - Nesting sites occur within Kakadu National Park (e.g. Field Island) and Cobourg National Park. Several other main sites are located on Indigenous owned land. Most sites are in very remote areas of coast isolated from current development (Chatto & Baker 2008).

Western Australia - Nesting occurs within the Montebellow Islands Conservation Park and the Barrow Island Nature Reserve. However, these islands contain large oil and gas infrastructure which are likely to impact nesting turtles and hatchlings (Pendoley 2005).

Post-hatchling and juvenile Flatback Turtles do not have the wide dispersal phase in the oceanic environment like other sea turtles (Walker & Parmenter 1990).

Adults inhabit soft bottom habitat over the continental shelf of northern Australia, extending into Papua New Guinea and Irian Jaya (Spring 1982; Zangerl et al. 1988) although the extent of their range is not fully known (Zangerl et al. 1988). Capture locations from trawlers indicate that Flatback Turtles feed in turbid, shallow inshore waters north of latitude 25° S in depths from less than 10 m to depths of over 40 m (Robins 1995). Nesting habitat includes sandy beaches in the tropics and subtropics with sand temperatures between 25 °C and 33 °C at nest depth (Limpus 1995a).


Hatchling to subadult Flatback Turtles lack a pelagic life stage and reside in the Australian continental shelf (Walker 1994; Walker & Parmenter 1990). Flatback Turtles require sandy beaches to nest. Sand temperatures between 25 °C and 33 °C are needed for successful incubation. Beaches free from light pollution are required to prevent disorientation, disturbance, and to allow nesting females to come ashore.


The species does not use refuge habitat.


The species is not dependent on a threatened ecological community. Flatback Turtles share nesting and foraging habitats with other marine turtle species.

While absolute age has not been determined in wild turtles, Flatback Turtles are presumed to be slow growing, taking decades to grow from hatchlings to breeding adults (Limpus 2007). As part of a long-term growth/aging study, the first adult, tagged as a hatchling at the Mon Repos rookery, returned for her first breeding at 21 years of age (Limpus 1985 cited in Limpus 2007). The reproductive half-life is estimated at 10.1 years (Parmenter & Limpus 1995).

In southern Queensland, Flatback Turtle mating occurs before nesting begins in mid -October, with nesting occurring between October and January with the peak in December (Limpus 2007). In northern Australia, nesting occurs throughout the year with most nesting between June and August (Guinea 1994a; Guinea & Whiting 1999). In western Northern Territory, some nesting occurs year round though nesting density reaches a peak in July (Fry 1913 in Limpus 2007). This dry season peak of nesting activity may be adaptive to protect the eggs from the high lethal sand temperatures that occur in the wet season (Guinea 1994 in Limpus 2007). In the Pilbara region of Western Australia, peak nesting occurs in the summer months while in the Kimberley region nesting occurs in the middle of the year (Prince 1994a, b).

Females lay a mean of 2.8 clutches per season at an inter-nesting interval of 15 days. Clutches contain approximately 50 eggs with an average size of 5.2 cm in diameter and 78 g in weight. Clutches are laid at a depth of 55 cm (Limpus 1971). The sex ratio of the hatchlings is determined by the temperature of the sand, with males produced below 29 °C and females produced above this temperature (see Limpus 1995a). Flatback Turtles breed at intervals between one to five years (i.e. remigration interval) with a mean of 2.7 years (Limpus et al. 1983a, b).

Clutches of eggs are susceptible to a number of natural disturbances, including nest disturbance by other nesting female turtles; flooding; or erosion of nests in storm events (Limpus 2007). Egg and hatchling survivorship is variable across the various rookeries, averaging around 80% (Limpus 1971) though the success of incubation and emergence of hatchlings is high in those rookeries free from disruption (Limpus 2007). Eggs incubate for around six weeks before hatchlings emerge from the nest and enter the sea. Predation of hatchlings as they cross the beach to the sea by birds, small crocodiles and crabs can be significant, though Limpus (1973, cited in Limpus 2007)) recorded hatchling survivorship at greater than 0.96 at Mon Repos Island, Queensland.

Post-hatchlings are surface-water dwelling, feeding on macroplankton. These post-hatchlings are predated on by fish and sharks and White-bellied Sea Eagles (Haliaeetus leucogaster). The duration of the post-hatchling life stage is unknown (Limpus 2007).

Unlike other sea turtle species, Flatback Turtles lack an oceanic phase and remain in the surface waters of the continental shelf (Limpus et al. 1994e; Walker 1994). Once the pelagic stage of its life is completed, the Flatback Turtle moves to sub-tidal soft bottomed habitats inshore, feeding on benthic organisms. Little is known about their foraging habits and habitat.

Survivorship data is lacking for the majority of the life history of the Flatback Turtle. Survivorship from hatchling emergent to maturity is estimated at less than 0.0026 (Parmenter & Limpus 1995). Annual survivorship of adult females on nesting beaches is greater than 0.99 (unpublished data in Limpus 2007).


Breeding rates for adult females are not known for any population. As with all marine turtles, seasonal breeding in Flatback Turtles is tied to incubation conditions (in particular sand temperatures need to be between 25 °C and 32 °C), hatchling dispersal and courtship (Hamann et al. 2002). Genetic testing by Theissinger and colleagues (2008) indicates that multiple paternity is common in the Flatback Turtle and that the observed frequency of multiple paternity is among the higher in marine turtles.

The female Flatback Turtle displays a high degree of fidelity to her chosen nesting beach, with most females returning to the same beach within a nesting season and in successive nesting seasons (Limpus 2007). It is not known, however, whether this fidelity is the result of imprinting to the natal beach during the egg or hatchling phase (Limpus 2007). Flatback Turtles show a preference for nesting in sand dunes or the steep seaward slope of beaches and rarely come ashore to nest on beaches fronted by intertidal coral reef flats. Rookeries that are fronted by sand/mud intertidal substrates are preferred in the major breeding aggregation areas of eastern Queensland (Limpus 2007).

Successful incubation of eggs require temperatures within the nest of between 25 ºC and 33 ºC, good ventilation, low salinity, high humidity and no disturbance (such as rotation) of the egg. While Flatback Turtle eggs are more tolerant of fluctuations in temperature and moisture than other turtle species, Hewavisenthi and Parmenter (in Limpus 2007) found that hatchlings raised in lower temperature conditions had lower energy reserves than those raised in higher temperature conditions.

Disruptions to nests include flooding and erosion, predation by feral and native animals and disturbance by other nesting turtles. In addition, some preferred nesting sites have been inadvertently fenced off (for beach erosion control), forcing nesting turtles to move to sub-optimal areas which in turn lowers clutch and hatchling survivorship rates (Limpus 2007). Emergent hatchlings make their way to the ocean by orienting themselves to the low elevation light horizon.

The strong nest site fidelity shown by the Flatback Turtle makes this species susceptible to the hazards of nest site disturbance, particularly considering that a first-time nesting turtle may be returning to her "pre-determined" nest site some 20 years after her own emergence from the nest, during which time the suitability of the nest site may have decreased. For instance, predators may have been introduced or increased (pigs, foxes or dogs), human interference may have increased (infrastructure, access and light pollution) or beach morphology changed.

Little is known about the diet of the Flatback Turtles, however juveniles are known to eat gastropod molluscs, squid and siphonophores (soft corals, hydroids, jellyfish) (Zangerl et al. 1988). Limited data indicate cuttlefish (Chatto et al. 1995) and crinoids (sea lilies) also form part of the diet (Zangerl et al. 1988).


Studies of feeding behaviour have not been conducted.

Flatback Turtles make long reproductive migrations similar to other species of sea turtles, although these movements are restricted to the continental shelf. Turtles tagged at rookeries in southern Queensland were recaptured at distances between 216 and 1300 km from their nesting beach (Limpus et al. 1983a).


No studies of home ranges have been conducted.

The Flatback Turtle is characterized by four pairs of costal (between the centre and outer margin of shell) scales and a distinct flattened carapace. For trained people, Flatback Turtles are relatively easy to distinguish from other marine turtle species using both the identification of the turtle itself or by viewing tracks.

Nesting beaches
There are essentially three methods which can be used singly or in combination to monitor nesting populations - aerial track counts, beach based track counts and individual marking. Each method has associated error, costs, advantages and disadvantages.

The specific methods used for nesting beach surveys for Flatback Turtles will be site specific and depend on ease of access to the sites, cost of surveys, availability of staff/volunteers, and time of year. Pritchard and Mortimer (1999) provide some detail on identification of eggs, hatchlings and adults as well as guidelines for monitoring nests.

Foraging studies
There are large gaps in the knowledge of Flatback Turtle biology outside of the nesting beaches. Studies that address foraging area distribution, abundance and population dynamics are warranted.

Flatback Turtles face a number of threats associated with the following broad categories of human activity: commercial and recreational fishing; coastal infrastructure and development (including industrial, residential and tourism development); Indigenous harvest; feral animal predation; and climate change. Some specific threats, such as light pollution, may be associated with more than one of these broad categories.

Fishing - commercial and recreational
While commercial harvest of turtles in Australia is no longer allowed, death or injury to turtles as a result of incidental capture (or bycatch) is a significant threat; in particular, through trawling, gillnet fishing and set crab pots. In addition, entanglement in lost or discarded nets represents a very large threat.

Trawling
Hundreds of Flatback Turtles used to be killed annually in trawling activities in northern Australia (EA 2003ai) prior to the introduction of Turtle Excluder Devices (TEDs). Between 1991 and 1996, it is estimated that the Queensland East Coast Trawl Fisheries and the Torres Strait Prawn Fishery caught, on average, around 1368 Flatback Turtles each year, of which around 23–43 died (Robins 1995, Robins & Mayer 1998 cited in Limpus 2007). Poiner and Harris (1994, 1996 cited in Limpus 2007) estimated that around 335 Flatback Turtles were killed in both 1989 and 1990 in the Northern Prawn Fishery (NPF). The introduction of TEDs within all trawl fisheries (TEDs were made mandatory in the Queensland East Coast Otter Trawl fishery in 1999 and in the NPF in 2000) has seen the number of turtles captured and killed reduced significantly. A comparison of the Northern Prawn Fishery Data Summary reports (Garvey & Lilley 2002; Perdraeu & Garvey 2005) show that the number of turtles caught in trawl nets in this Fishery dropped from 780 in 1999 (with 248 deaths of Flatback Turtles) to 24 turtles caught in 2004 (with no Flatback Turtle mortalities).

Gill nets
Marine turtles may also become entangled in nets set for inshore fish species, such as barramundi and shark (DEWHA in prep.). In 1991, 24 Flatback Turtles were drowned in one shark net over a a two-week period (Guinea & Chatto 1992) while Limpus (2007) reported that Flatback Turtles are regularly drowned in gill nets set along the coast of the south-eastern Gulf of Carpentaria.

Longline and Pot Fishing
Turtles may be hooked on, or entangled in, fishing line. Williams and colleagues (1996) report that turtles can be hooked on the front and hind flippers, head, mouth, neck and carapace or get entangled in either the monofilament, mainline or balldrop/buoy line. In pot fisheries, turtles may become entangled in the float lines or enter pot traps and drown (DEWHA in prep.). While the threat of these fisheries on Flatback Turtles has not been well quantified, around 400 turtles each year are accidentally caught by the two major longline fisheries, Eastern Tuna and Billfish Fishery and the Southern and Western Tuna and Billfishery (DEWHA in prep.). In pot fisheries, turtles may become entangled in the float lines or enter pot traps and drown (DEWHA in prep.), however, there are no reports, to date, of Flatback Turtles being captured in floatlines to crabpots or similar buoy lines (Limpus 2007).

Ghost Nets
Ghost nets (lost and discarded fishing nets) pose a serious threat to marine turtles as they float in the ocean and coastal waters and indiscriminately capture marine animals (DEWHA in prep.). Ghost nets in the Gulf of Carpentaria are brought in by the wind and currents which then trap and circulate the nets in the Gulf indefinitely (DEWHA in prep.). The origin of the nets (from which sea or ocean) has yet to be resolved, with modelling suggesting a South Pacific origin and a route through the Torres Strait rather than drift from the Indian Ocean or the Arafua Sea (Griffin 2008). White (2006) found 406 discarded nets, weighing nearly 900 kg, over 28.6 km of coastline surveyed along six sites along the coastline of Arnhem Land and the Gulf of Carpentaria. Roeger and colleagues (2005, cited in DEWHA in prep.) found, in their survey, significant amounts of nets and marine debris in the Gulf of Carpentaria. On the basis of aerial surveys of the eastern Gulf, Limpus (pers. comm. cited in Kiesling 2003) estimates that a total of around 10 000 nets (or around 250 kg of fishing net per km) may be on Queensland coastline of the Gulf. Limpus (unpublished data in Limpus 2007) estimated that in the six weeks following a cyclone in February 2001, over 4000 nets washed ashore in the eastern Gulf of Carpentaria coastline, trapping in excess of 400 turtles. While the turtle mortality associated with ghost nets in the Gulf of Carpentaria is unquantified, it is likely to amount to many hundreds of turtles per year (Limpus 2007). Recreational fishing can also result in discarded nets and ropes which, when left on nesting beaches, have been known to trap nesting adult females (Limpus 2007).

Coastal Infrastructure and Development

Coastal developments, including residential, industrial and tourism development, can directly destroy or degrade beach habitats used as nesting sites for Flatback Turtles as well as degrade foraging habitat. Coastal development can also have indirect, but often cumulative, effects on nesting and foraging habitat.

Light Pollution
Light pollution on nesting beaches alters nocturnal behaviors in sea turtles, including; how sea turtles choose nesting sites; how they return to the sea after nesting; and how hatchlings find the sea after emerging from their nests (Witherington & Martin 1996).

Light pollution can affect the beach finding ability or nesting behaviour of adult turtles (Salmon et al. 2000 cited in Limpus 2007). The most clearly demonstrated effect of artificial lighting on nesting is to deter turtles from emerging from the water (Witherington & Martin 1996). As such, Witherington and Martin (1996) regard artificial lighting of sea turtle nesting beaches as a form of habitat loss. If sea turtles can't choose the most favourable nesting sites, the use of sub-optimal nesting beaches may compromise hatchling fitness, sex ratio and survirvorship (Limpus 2007; Witherington & Martin 1996).

In addition to the threat that this "loss of habitat" poses, artificial lighting can also disorient nesting turtles on their way back to the water, though adult disorientation is not as marked as hatchling disorientation. Witherington (1992a cited in Witherington & Martin 1996) found that few nesting turtles returning to the sea were misdirected by lighting; however, those that were (four Green turtles and one Loggerhead) spent a large portion of the night wandering in search of the ocean. Hodge and colleagues (2007) documented disorientation of nesting Flatback females at a minor Flatback nesting beach at Hummock Hill Island, Queensland. They determined that this disorientation was caused by the brightly illuminated salt-spray atmosphere above an alumina refinery sited some 18 km away from the nesting beach.

Artificial lighting disrupts hatchlings in their journey from the nest to the sea. On naturally lighted beaches, hatchlings show an immediate and well-directed orientation toward the water - delay in the journey from nest to sea is often met with death from exhaustion, dehydration, predation or other causes (Witherington & Martin 1996). This sea-finding behavior is innate and is guided by light cues that include brightness, shape, and in some species, colour (Lorne & Salmon 2007; Salmon 2003; Witherington & Martin 1996). Artificial lighting on beaches is strongly attractive to hatchlings and can cause hatchlings to move in the wrong direction (misorientation) as well as interfere with their ability to orient in a constant direction (disorientation) (Witherinton & Martin 1996).

This misorientation or disorientation can lead to higher mortality such as when hatchlings move away from the water and toward another light source such as residential or industrial lighting. Disorientation of Flatback Turtle hatchlings by street lighting at Port Hedland is a regular occurence, leading hatchlings into the path of road traffic (Limpus 2007).

Light pollution can be generated by residential and tourism infrastructure (such as urban lighting that is visible behind the dunes of a beach or high bright lights associated with signage on buildings) as well as large industrial developments, such as gas and oil infrastructure or port facilities, which, for either security or 24-hour operation processes, are lit throughout the night. Barrow Island, off the coast of Western Australia, supports a large gas and oil processing operation, as well as an important Flatback Turtle rookery. Six nesting beaches on Barrow Island are exposed to artificial light, with the result that around 40% of all Flatback Turtle nesting is potentially affected by artificial lights (Pendoley 2005).

Through the conduct of experiments based at Barrow Island (and nearby islands), with both controlled and uncontrolled lighting, Pendoley (2005) documented the effect that different light types, intensities and distances from nesting beaches had on hatchling orientation. These studies demonstrated that there are many variables associated with the potential impact, such as the presence or absence of headlands, the lunar cycle and the species' particular sensitivity to the light spectrum. Nonetheless, Pendoley (2005) showed conclusively that Flatback hatchlings exposed to artificial light orient themselves significantly differently to hatchlings not exposed to artificial lights, though both light type and intensity, as a function of distance, are important variables. Pendoley (2005) concluded that sodium vapour lights had less potential to misorient Flatback Turtle hatchlings than flouride or metal halide light sources, when all other factors (intensity and distance) are equal. In addition to the role that artificial lights may play in disorienting hatchlings from the preferred route to the ocean, artificial lights can also make it easier for predators, such as birds, to find the hatchlings as they make their way to the water (Limpus 2007; Witherington & Martin 1996).

While residential and tourism infrastructure along the eastern coastline does present a source of artificial lighting that can degrade the nesting opportunities and survivorship of Flatback Turtle hatchlings, Limpus (2007) identifies the growing oil and gas infrastructure development on the otherwise quite isolated nesting beaches off the Western Australian coast as a growing threat. As these isolated islands are developed, and there is an increase in "drilling rigs, work boats, offshore flares and construction barges", the more the natural light horizons will be altered (Limpus 2007) and the greater the management challenge will become.

Habitat Degradation
Coastal development can inhibit turtle access to nesting beaches, either through the presence of physical barriers or indirectly through reducing the amenity of nesting beaches or foraging areas. Camping and vehicle traffic on beaches can damage turtle nesting areas by compacting the sand, increasing dune erosion and creating wheel ruts that trap hatchlings (DEWHA in prep.). Uncontrolled camping may disrupt nesting turtles or damage nests and turtles may be displaced by harassment by humans or pet animals. In the Northern Territory, Quail Island and Bare Sand Island are significant Flatback Turtle rookeries but are also used as a bombing range by the Royal Australian Air Force (Limpus 2007), though the impact of this activity has not been quantified. Port developments can also bring with them increased vessel activity, dredging of shipping channels and the potential for habitat degradation through accidental spillages of oils and chemicals (Limpus 2007). This is particularly relevant to Dampier/Karratha and Port Headland in Western Australia and for planned port developments in the Gulf of Carpentaria, including the Flatback Turtle foraging habitat adjacent to Weipa and Karumba in Queensland and MacArthur River, Groote Ehylandt and Gove in Northern Territory (Limpus 2007). Increased pollution of foraging areas (such as seagrass meadows and coral reefs) from runoff of nutrients, sediments, pesticides can decrease water quality which in turn can degrade foraging resources.

Boat Strike
Fast moving boats have the potential to cause marine turtle injury or death (DEWHA in prep.). Between 1995 and 2003, there were three cases of Flatback Turtle death caused by boat strike (EPA Marine Wildlife Stranind and Mortality Database cited in Limpus 2007). Hazel and colleagues (2007) showed that turtles (Green Turtles) were unable to avoid being struck by a 6 m aluminium boat travelling at speeds in excess of 4 kph (2 knots).

Marine Debris
Death can occur when turtles become entangled in, or ingest, marine debris. Carr (1987 cited in DEWHA in prep.) records that fishing line, rope and cord fragments, styrofoam beads, tar balls, plastic bags and balloons are all known to have killed marine turtles through ingestion or entanglement. During 1995–2003, there were two cases of post-hatchling deaths attributed to oil fouling and three deaths attributed to entanglement or ingestion of plastic or other synthetic debris in Queensland (EPA Marine Wildlife Stranding and Mortality Database cited in Limpus 2007). Chatto and colleagues (1995 cited in Limpus 2007) document one death of a Flatback Turtle by ingeston of plastic debris in Darwin.

Shark Control Programs
Flatback Turtles have been captured in shark control nets in Queensland (Limpus 2007) though it is estimated that there may be as few as one death per year in Queensland due to drowning in shark control nets.

Indigenous Harvest

Marine turtles are economically and culturally significant to Indigenous Australians (Aboriginal and Torres Strait Islanders) (DEWHA in prep.). In general, adult turtles are harvested for their meat. Eggs are also collected by Indigenous Australians. Under the Australian Government's Native Title Act 1993, Indigenous Australians with a native title right (either determined or at common law) may exercise their traditional hunting rights, provided it is for personal, domestic or non-commercial communal needs. However, Indigenous harvest of eggs may impact significantly on some populations of Flatback Turtles in northern Australia (DEWHA in prep.). Harvests of Flatback Turtle eggs have been reported in Arnhem Land (Guinea 1990), Fog Bay (Guinea & Whiting 1999) and widely across the Northern Territory mainland and island beaches (Chatto & Baker 2008).

Animal Predation

Goannas destroy a significant number of nests in northern Australia: in Fog Bay and Cobourg Peninsula, Northern Territory, 52% (Blamires 1999) and 58% (Hope & Smit 1998) of all nests were raided by goannas. Pigs destroy up to 90% of the nests on western Cape York (Limpus et al. 1993). Foxes and dogs destroy hundreds of nests in eastern Queensland (EA 2003ai). Chatto and Baker (2008) record that around 8% of all nestings recorded in the Northern Territory between 1994–2004 were disturbed by goannas (over 500 nests), dogs (over 400 nests) or other unknown predators (nearly 300 nests).

Seismic Survey

While seismic surveys, which produce noise pollution in the water, are unlikely to cause the death of turtles, they may impact on the foraging, inter-nesting, courting or mating behaviour of turtles. McCauley and colleagues (2000, cited in Limpus 2007) document the circumstances in which turtles will change behaviour as a result of seismic surveys and recommend the timing and location of seismic surveys take into account time and place specific activities of turtles.

Human Interactions with Turtles Outside Australia's Jurisdiction

As marine turtles are migratory, threats to turtles, originating in other countries (such as nesting beach degradation, tourism, fishing and pollution of foraging areas) may result in population decline in species nesting or foraging in Australia. While all recorded nesting sites for Flatback Turtles are in Australia, the Flatback Turtle does forage in water as far north as the Gulf of Papua in Papua New Guinea and the coastal water of Papua in Indonesia (Samertian & Noija 1994 cited in Limpus 2007).


Climate Change

Changing termparatures and weather patterns associated with climate change are likely to have both direct physiological impacts on marine turtles, as well as indirect effects through impacts on critical turtle habitats (DEWHA in prep.). The sex of marine turtle hatchlings is determined by the incubation termperature of the eggs, with warmer incubation temperatures leading to the production of female hatchlings and cooler incubation temperatures leading to production of male hatchlings. Climate change may alter the temperature of nesting beaches, thereby affecting the male/female ratio.

Rising sea levels and an increase in the frequency and/or intensity of cyclones and associated storm surges could lead to erosion of nesting beaches, changes in beach morphology, washing away or inundation of nests (Hamann et al. 2007). Changes in ocean circulation patterns and alteration to marine food webs may both have significant impacts on Flatback Turtles, particulary during their pelagic phase (DEWHA in prep.). The long life span and long maturation and reproductive times of Flatback Turtles reduces the ability of these animals to adapt to changes in environmental conditions likely to be associated with climate change (DEWHA in prep.).


Longevity, slow growth and delayed sexual reproduction are all life history traits of Flatback Turtles that hinder efforts to identify population trends and also act to prevent fast population recovery.

National Recovery Plan

The Recovery Plan for Marine Turtles in Australia (EA 2003ai) outlines actions for the protection, conservation and management of the six marine turtles listed under the EPBC Act, including the Flatback Turtle. A draft of this Plan is currently being reviewed (DEH 2005a).

Fishing

Both Commonwealth and State governments manage fisheries in Australia and each are subject to a mix of legislative, regulatory and policy instruments that contribute to reducing the threat that bycatch poses to marine turtles (EA 2003ai). The Australian Fisheries Management Authority (AFMA) shares responsibility for managing some fisheries with the States and Northern Territory, though in general States and the Northern Territory manage inshore species, such as rock lobster and abalone, whereas AFMA generally manages deeper water finfish and tuna species. AFMA is the Commonwealth agency responsible for implementing the Fisheries Management Act 1991 (FMA) and managing Commonwealth fisheries. The EPBC Act broadly requires that actions taken when fishing do not have a significant impact on the Commonwealth marine environment and its biodiversity, including protected species such as marine turtles. All Commonwealth fisheries have to assessed and accredited under Part 13 and 13A of the EPBC Act. Other more specific actions are controlled through recovery plans, wildlife conservation plans and threat abatement plans made under the EPBC Act as a result of a protected species listing or type of fishing activity being listed. For instance, Incidental catch (bycatch) of Sea Turtle during coastal otter-trawling operations within Australian waters north of 28º South was listed as a key threatening process in 2001 under the EPBC Act.

Relevant Commonwealth policies and programs include the Guidelines for the Ecologically Sustainable Management of Fisheries 2007 and AFMA's Bycatch and Discard Program. The Australian Government released the Commonwealth Policy on Fisheries Bycatch in 2000 to guide Commonwealth fisheries in the pursuit of legislative objectives relating to non-target species and the broader marine environment. The key tool used to pursue bycatch minimisation under the Commonwealth bycatch policy is the requirement for each fishery to implement a Bycatch Action Plan (BAP). AFMA (2008) established a Bycatch and Discarding Implementation Strategy to provide additional resources and direction for pursuing policy and legislative objectives in relation to bycatch and discarding.

Bycatch Action Plans (BAP)
Fishery bycatch action plans, developed with AFMA, that include turtle protection measures include the following BAPs:

  • Northern Prawn Fishery Management Advisory Committee Bycatch Action Plan (AFMA 2007)
    Strategies within this Plan include the modification of fishing gear, logbook programs, research on new technology and evaluation of the success of their programs. From 2002 to 2006, reported bycatch of turtles was reduced to <30 per year with no mortality. NPF has been re-certified as turtle safe by the United States of America.

  • Torres Strait Prawn Fishery Working Group Bycatch Action Plan (AFMA 2005)
    This Plan aims to eliminate as far as possible turtle bycatch through such strategies of fishing gear modification, the monitoring of turtle interactions and support for research into this area.

State governments are also responsible for managing a large number of commercial fisheries and each State has its own range of legislative, regulatory or policy instruments that serve to reduce bycatch of marine turtles.

Torres Strait Dugong and Turtle Fisheries
Only Traditional Inhabitants of the Torres Strait and PNG Treaty villages are allowed to take dugongs or turtles. Management regulations currently implemented in the Torres Strait Dugong and Turtle Fisheries include:

  • Dugongs and turtles may only be taken by Traditional Inhabitants.
  • Dugongs and turtles cannot be taken or carried in a commercially licenced fishing boat greater than 6 m in length (boats under 6 m with a TIB licence are permitted to take and carry turtle and dugong).

    In addition, Traditional Owners from the Kimberley, Top End of the Northern Territory, southern Gulf of Carpentaria, Cape York and the Torres Strait have joined forces to develop community-driven approaches to the sustainable management of dugong and marine turtle in northern Australia under the North Australian Indigenous Land and Sea Management Alliance (NAILSMA) and the Cooperative Research Centre for Tropical Savannas (NAILSMA 2008).

    The project partners of the Dugong and Marine Turtle Project are:

    Kimberley Land Council
    Northern Land Council
    Carpentaria Land Council Aboriginal Corporation
    Balkanu Cape York Development Corporation
    Torres Strait Regional Authority.

    The partner organisations oversee the delivery of the project through management and activity plans.

    Ghost nets
    There is a substantial network of communities working together to remove ghost nets from beaches, quantify its impact and reduce turtle mortality (Ghost Nets and NRM Ghost Nets).

    A comprehensive assessment of the nature and impact of marine debris was made in 2003 (Kiesling 2003). This study detailed 25 activities that could be implemented to help reduce the volume and impact of marine debris, including in matters of research and monitoring, communication, education and outreach, incentives, regulation and technical advances.

    A key advance in the monitoring of ghost nets was the release of the tool "The Net Kit: A Fishing Net Identification Kit for Northern Australia" by the World Wildlife Fund in 2002 (with support from the Natural Heritage Trust) (White 2006).

    While the majority of nets found in the Gulf of Carpentaria are of foreign origin, a pilot study to model drift and circulation patterns (Griffin 2008) found no evidence that nets stranding on the shores of Arnhem Land and Gulf of Carpentaria were likely to have been lost or discarded in south east Asian waters farther away than the Arafura Sea. Instead, modelling indicated that marine debris passing through Torres Strait was likely to come close to the Arnhem Land coastline, or enter the Gulf of Carpentaria, where it might strand in the Cape Arnhem-Groote Eylandt region in the Dry Season, or in the Weipa region during the Wet Season (Griffin 2008). Understanding where marine debris is coming from is an important prerequisite for management of the threat that marine debris poses to Flatback and other turtles.

    Habitat Protection

    The Commonwealth acts in a number of ways to protect turtles, both as a manager of reserves, as a manager of fisheries as well through conservation programs. Declaration of protected areas to conserve threatened species is one approach (EA 2003ai). The Great Barrier Reef Marine Park (GBRMP) is one of the world's most extensive protected areas, protecting significant amounts of marine turtle habitat. The Great Barrier Reef (GBR) is included on the World Heritage List with marine turtles identified in the nomination as one of its natural attributes. Internationally significant populations of Green, Hawksbill, Loggerhead and Flatback Turtles occur on the GBR. A large number of islands and their adjacent waters are closed to visitation seasonally under management plans or permit conditions restricting access for the purposes of seabird and turtle protection. The Commonwealth also monitors nesting marine turtles and hatching success in the Coral Sea National Nature Reserves, on Field Island in Kakadu National Park and at Ashmore Reef National Nature Reserve (EA 2003ai).

    States also play a large part in the protection of areas known to be significant to Flatback Turtles and in undertaking research and monitoring of important rookeries. Western Australia, Queensland, NSW and the Northern Territory have all developed or assisted with turtle monitoring, research, rescue and protection. Most significant rookeries in Queensland have been declared protected habitat under the Queensland Nature Conservation Act 1992 and the Queensland Environment Protection Agency has had a long-running monitoring, research and mangement program (EA 2003ai).

    Climate change
    Climate change impacts are being monitored through a DEWHA initiative to record sand temperatures for major rookeries for each genetic stock (funded under the NHT Marine Turtle Recovery Scheme - Sand temperature variability and nest depth at index beaches for marine turtles across Australia).

    Climate change impacts are being monitored by the QPWS turtle research project by conducting detailed sand temperature studies at Mon Repos. Sand temperatures at Mon Repos beach have been routinely collected by QPWS since the mid 1970s.

    More effort should be placed on understanding patterns of nest site selection and how nesting sites may change under different climate regimes (Hamann et al. 2007) and understanding the ecological roles of Flatback Turtles and possible impacts of climate change to important diet species (Hamann et al. 2007).

  • Feral Animals
    The Queensland State government has been conducting large scale pig removal programs in northern and western Cape York Peninsula to improve hatchling survival. Fox baiting by QPWS staff continues along the mainland coast adjacent to Flatback Turtle rookeries. Limpus and Limpus (2003) indicate that as a result of fox control, fox predation of nests laid on mainland beaches is negligible.

    Further monitoring

    There are significant gaps in knowledge about Flatback Turtle populations and future research and monitoring could address the following matters:

    • Nesting beach based population surveys at one or more index sites for the Gulf of Carpentaria and Western Australian populations.
    • Surveys of predation rates and hatchling production at main rookeries in the northern and western Australian populations.
    • Experimental and/or comparative studies that address the impacts of light pollution on the behaviour, survival, physiology and reproductive biology of hatchling and adult turtles.
    • Experimental and/or comparative studies that address the impacts of climate change on the behaviour, survival, physiology and reproductive biology of hatchling and adult turtles.

    There have been no mitigation approaches developed specifically for Flatback Turtles. However, Flatback Turtles benefit from generic approaches developed to protect marine turtles such as inclusion of TEDs in fisheries and feral animal control on nesting beaches.

    As a condition of approval under the EPBC Act 1999 for the construction and operation of a gas processing plant on Barrow Island, the proponents will spend $30 million over 30 years on marine turtle baseline, impact and management activities (EPBC Reference 2004/1294).

    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 Flatback Turtle has been identified as a conservation value in the North (DSEWPaC 2012x) and North-west (DSEWPaC 2012y) marine regions. See Schedule 2 of the North-west Marine Bioregional Plan (DSEWPaC 2012y) and the North Marine Bioregional Plan (DSEWPaC 2012x) for regional advice. Maps of Biologically Important Areas have been developed for flatback turtle in the North (DSEWPaC 2012x) and North-west (DSEWPaC 2012y) marine regions 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 - marine reptiles" for the North-west (DSEWPaC 2012y) and North (DSEWPaC 2012x) marine regions provide additional information.

    QPWS conduct annual nesting beach surveys at Mon Repos, Peak Island, Curtis Island and near annual surveys at Wild Duck Island to determine annual nesting trends, hatchling production and predation rates.

    QPWS in cooperation with Indigenous Groups conduct annual beach surveys along Western Cape York Peninsula to determine annual nesting trends, hatchling production and predation rates.

    Kakadu National Park staff conducts annual nesting beach surveys at Field Island to determine annual nesting trends, hatchling production and predation rates.

    Annual nesting beach surveys at Bare Sand Island are undertaken to determine annual nesting trends, hatchling production and predation rates and Chatto and Baker (2008) have released a comprehensive report on surveys in the Northern Territory

    There are Flatback Turtle surveys conducted at Barrow Island (eg Pendoley 2005) and these studies are supported by the mining industry and State conservation departments. They include tagging census work and satellite tracking.

    Flatback Turtle hatchling movements are being investigated by researchers at James Cook University through the tracking of transmitters put on hatchlings ( IPSTCG 2006).

    In a study on the blood properties of Flatback Turtles, Sperling and colleagues (2007) suggest that Flatback Turtles have a respiratory physiology particularly suited to sustain prolonged shallow dives.

    Major management documents relevant to the protection of the Flatback Turtle include:

    Recovery Plan for Marine Turtles in Australia (EA 2003ai)

    Threat Abatement Plan for Predation, Habitat Degradation, Competition and Disease Transmission by Feral Pigs Department of the Environment and Heritage (AGDEH) (2005p)

    Guidelines for the Ecologically Sustainable Management of Fisheries (DEW 2007).

    The North Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North Marine Region (DEWHA 2008)

    An issues paper on protection of sea turtles is in preparation (DEWHA in prep.). In addition, fisheries, both Commonwealth and State managed, are guided by bycatch action plans and ecological assessment processes.

    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:Incidental capture and death due to trawling fishing activities Draft Recovery Plan for Marine Turtles in Australia (Env. Aust, 1998) [Recovery Plan].
    Commonwealth Listing Advice on Incidental catch (bycatch) of Sea Turtle during coastal otter-trawling operations within Australian waters north of 28 degrees South (Threatened Species Scientific Committee (TSSC), 2001x) [Listing Advice].
    Biological Resource Use:Fishing and Harvesting Aquatic Resources:Indigenous hunting and harvesting Natator depressus in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006pe) [Internet].
    Biological Resource Use:Fishing and Harvesting Aquatic Resources:Mortality due to capture, entanglement/drowning in nets and fishing lines Natator depressus in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006pe) [Internet].
    Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation Vulpes vulpes (Red Fox, Fox) Natator depressus in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006pe) [Internet].
    Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation Canis lupus familiaris (Domestic Dog) Natator depressus in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006pe) [Internet].
    Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Grazing, tramping, competition and/or habitat degradation Sus scrofa (Pig) Natator depressus in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006pe) [Internet].
    Crab Island revisited: reassessment of the world's largest flatback turtle rookery after twelve years. Memoirs of the Queensland Museum. 33(1):277-289. (Limpus, C.J., P.J. Couper & K.L.D. Couper, 1993) [Journal].
    Commonwealth Listing Advice on Predation, Habitat Degradation, Competition and Disease Transmission by Feral Pigs (Threatened Species Scientific Committee, 2001ab) [Listing Advice].
    Invasive and Other Problematic Species and Genes:Problematic Native Species:Predation by reptiles Natator depressus in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006pe) [Internet].
    Pollution:Garbage and Solid Waste:Ingestion and entanglement with marine debris Natator depressus in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006pe) [Internet].

    Australian Fisheries Management Authority (AFMA) (2005). Torres Strait Prawn Fishery Bycatch Action Plan 2005. [Online]. Developed by the Torres Strait Prawn Fishery Working Group. Available from: http://www.afma.gov.au/information/publications/fishery/baps/docs/torres_bap_final.pdf.

    Australian Fisheries Management Authority (AFMA) (2007). Northern Prawn Fishery Bycatch Action Plan 2007. [Online]. Prepared in conjunction with the Northern Prawn Fishery Management Advisory Committee. Available from: http://www.afma.gov.au/information/publications/fishery/baps/docs_reports/npf_final_2007.pdf.

    Australian Fisheries Management Authority (AFMA) (2008). AFMA's Program for Addressing Bycatch and Discarding on Commonwealth Fisheries:an Implementation Strategy. [Online]. Australian Government. Available from: http://www.afma.gov.au/environment/bycatch/is_env_bycatch-prog_feb08_20080417.pdf.

    Blamires, S.J. (1999). Quantifying the impact of predation on sea turtle nests by varanids at Fog Bay. M.Sc. Thesis. Darwin: Northern Territory University.

    Bowlay, A., Whiting, A. (2007). Uncovering Turtle Antics. Landscope. 23 (2). Western Australia Department of Environment and Conservation.

    Bustard, R. (1972). Australian Sea Turtles: Their Natural History and Conservation. Page(s) 220. London, Collins.

    Chatto, R. (1998). A preliminary overview of the locations of marine turtle nesting in the Northern Territory. In: Kennett, R., A. Webb, G. Duff, M. Guinea & G. Hill, eds. Proceedings of a Workshop held at the Northern Territory University, 3-4 June 1997. Centres for Indigineous Natural Culture Resource Management/Tropical Wetland Management. Darwin, Northern Territory University.

    Chatto, R., & B. Baker (2008). The distribution and status of marine turtle nesting in the Northern Territory-Technical Report 77/2008. [Online]. Parks and Wildlife Service, Department of Natural Resources, Environment, The Arts and Sport. Northern Territory Government. Available from: http://www.nt.gov.au/nreta/publications/wildlife/science/pdf/marine_turtle_nesting.pdf.

    Chatto, R., M.L. Guinea & S. Conway (1995). Sea turtles killed by flotsam in northern Australia. Marine Turtle Newsletter. 69:17-18.

    Cogger, H.G. (1996). Reptiles and Amphibians of Australia. Chatswood, NSW: Reed Books.

    Cogger, H.G. (2000). Reptiles and Amphibians of Australia - 6th edition. Sydney, NSW: Reed New Holland.

    Cogger, H.G. (1994). Reptiles and Amphibians of Australia. Chatswood, Reed Books.

    Department of the Environment and Heritage (2005b). Draft Recovery Plan for marine turtles found in Australia: Olive Ridley Turtle Lepidochelys olivacea, Loggerhead Turtle Caretta caretta, Flatback Turtle Natator depressus, Green Turtle Chelonia mydas, Hawksbill Turtle Eretmochelys imbricata & Leatherback. [Online]. Canberra: Commonwealth Department of Environment and Heritage. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/recovery/marine-turtles/pubs/marine-turtle.pdf.

    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) (in prep.). Issues paper for six species of marine turtles found in Australian waters that are listed as threatened under the Environment Protection and Biodiversity Conservation Act 1999. [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/recovery/marine-turtles/pubs/issues-paper.pdf.

    Dobbs, K.A. (2007). Marine turtle and dugong habitats in the Great Barrier Reef Marine Park used to implement biophysical operational principles for the Representative Areas Program. Unpublished Report of the Great Barrier Reef Marine Park Authority, Townsville.

    Dutton, P., D. Broderick & N. Fitzsimmons (2002). Defining Management Units: Molecular Genetics. Kinan, I., ed. Proceedings of the Western Pacific Sea Turtle Cooperative Research and Management Workshop. Page(s) 93-101. Honolulu: Western Pacific Regional Fishery Management Council.

    Environment Australia (EA) (2003ai). Recovery Plan for Marine Turtles in Australia - July 2003. [Online]. Canberra: Environment Australia. Available from: http://www.environment.gov.au/coasts/publications/turtle-recovery/index.html.

    Garvey, J., Lilley, S. (2002). Northern Prawn Fishery and Kimberley Prawn Fishery Data Summary 2001 Logbook Program. [Online]. Canberra, Australian Fisheries Management Authority. Available from: http://www.afma.gov.au/information/publications/fishery/data_summ/docs/npf_2000_01.pdf.

    Griffin, D (2008). Pilot investigation of the origins and pathways of marine debris found in the northern Australian marine environment. Report for the Department of the Environment, Water, Heritage and the Arts. [Online]. Centre for Australian Weather and Climate Research. Available from: http://www.environment.gov.au/coasts/publications/pubs/origins-marine-debris.pdf.

    Guinea, M. (1998). Sea turtle research at a Northern Territory University. In: Kennett, R., Webb, A., Duff, G., Guinea, M., Hill, G., ed. Marine turtle conservation and managemen tin northern Australia. Proceedings of a workshop held at the Northern Territory University 3-4 June 1997. Page(s) 49-53. Darwin, Centre for Indigenous Natural and Cultural Resource Management and Centre for Tropical Wetlands Management.

    Guinea, M.L. (1990). Notes on sea turtle rookeries on the Arafura Sea Islands of Arnhem Land, Northern Territory. Northern Territory Naturalist. 12.

    Guinea, M.L. (1994a). Nesting seasonality of the Flatback Sea Turtle Natator depressus (Garman) at Fog Bay, Northern Territory. In: James, R., ed. Queensland Department of Environment and Heritage and Australian Nature Conservation Agency. Page(s) 150-153. Qld Dept Env. & Heritage. Canberra, ANCA.

    Guinea, M.L. & R. Chatto (1992). Sea turtles killed in Australian shark fin fishery. Marine Turtle Newsletter. 57.

    Guinea, M.L. & S.D. Whiting (1999). Quail Island to Native Point sea turtle refuge. National Estates Grants Program. Darwin, Northern Territory University.

    Hamann, M., C. Limpus & M. Read (2007). Vulnerability of marine reptiles to climate change in the Great Barrier Reef. In: Johnson, J. & P. Marshal, eds. Great Barrier Reef Marine Park Authority and The Australian Greenhouse Office: Climate change and the Great Barrier Reef.

    Hamann, M., D. Owens & C.J. Limpus (2002). Reproductive cycles in male and female sea turtles. In: Lutz, P.L., J. A. Musick & J. Wyneken, eds. Biology of sea turtles. 2. Boca Raton, Florida: CRC Press.

    Hamann, M.Schauble, C.S. , T. Simon, S.Johnson Evans, J. Dorr, T. & R. Kennett (2006). Sea turtle nesting in the Sir Edward Pellew Islands; Gulf of Carpentaria, Northern Territory. Memoirs of the Queensland Museum. 52:71-78.

    Hodge, W., C.J. Limpus & P. Smissen (2007). Queensland Turtle Conservation Project: Hummock Hill Island Nesting Turtle Study December 2006. [Online]. The State of Queensland: Environmental Protection Agency. Available from: http://www.derm.qld.gov.au/register/p02213aa.pdf.

    Hope, R. & N. Smit (1998). Marine turtle monitoring in Gurig National Park and Coburg Marine Park. Page(s) 53-62. Centres for Indigenous Natural Cultural Resource Management/Tropical Wetland Management. Darwin: Northern Territory University.

    Indo-Pacific Sea Turtle Conservation Group (IPSTCG) (2006). November 2006 Newsletter. [Online]. Available from: http://www3.aims.gov.au/ipstcg/ipstcg-0611.html.

    Kiesling, I (2003). Finding solutions: Derelict fishing gear and other marine debris in northern Australia. [Online]. National Oceans Office. Available from: http://www.environment.gov.au/coasts/mbp/publications/north/pubs/marine-debris-report.pdf.

    Limpus, C. J. (1973). Avian predators of sea turtles in southeast Queensland rookeries. The Sunbird. 4:45-41.

    Limpus, C., Gyuris, E., Miller, J.D,. (1988). Reassessment of the taxonomic status of the sea turtle genus Natator. Transactions of the Royal Society of South Australia. 112:1-9.

    Limpus, C.J. (1971). The flatback turtle, Chelonia depressa garman in southeast Queensland, Australia. Herpetologica. 27:431-446.

    Limpus, C.J. (1995a). Conservation of marine turtles in the Indo-Pacific region. Brisbane: Queensland Department of Environment and Heritage.

    Limpus, C.J. (2007). A biological review of Australian marine turtle species. 5. Flatback turtle, Natator depressus (Garman). Queensland Environmental Protection Agency.

    Limpus, C.J. & D.J. Limpus (2003). Loggerhead turtles in the equatorial and southern Pacific Ocean: A species in decline. In: Bolten, A. and B. Witherington, eds. Loggerhead Sea Turtles. Page(s) 199-210. Washington, D. C: Smithsonian Institution Press.

    Limpus, C.J., C.J. Parmenter, R. Parker & N. Ford (1981). The flatback turtle Chelonia depressa in Queensland: the Peak Island rookery. Herpetofauna. 13(1):14-18.

    Limpus, C.J., C.J. Parmenter, V. Baker & A. Fleay (1983a). The Crab Island sea turtle rookery in north-eastern Gulf of Carpentaria. Australian Wildlife Research. 10:173-184.

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    Citation: Department of the Environment (2014). Natator depressus in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Mon, 22 Sep 2014 05:25:58 +1000.