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
Listed marine
Listed migratory - Bonn
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].
 
Other EPBC Act Plans Threat Abatement Plan for Predation, Habitat Degradation, Competition and Disease Transmission by Feral Pigs (Australian Government Department of the Environment and Heritage (AGDEH), 2005p) [Threat Abatement Plan].
 
Policy Statements and Guidelines Marine bioregional plan for the Temperate East Marine Region (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012aa) [Admin Guideline].
 
Marine bioregional plan for the North Marine Region (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012x) [Admin Guideline].
 
Marine bioregional plan for the North-west Marine Region (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012y) [Admin Guideline].
 
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].
 
List of Migratory Species (13/07/2000) (Commonwealth of Australia, 2000b) [Legislative Instrument].
 
Declaration under section 248 of the Environment Protection and Biodiversity Conservation Act 1999 - List of Marine Species (Commonwealth of Australia, 2000c) [Legislative Instrument].
 
State Government
    Documents and Websites
NT:Threatened Species of the Northern Territory - Hawksbill Turtle Eretmochelys imbricata (Taylor, R., R. Chatto, J. Woinarski, S. Whiting & S. Ward, 2012) [Information Sheet].
QLD:Hawksbill turtle (Department of Environment and Heritage Protection (DEHP), 2013ae) [Database].
TAS:Eretmochelys imbricata (Hawksbill Turtle): Species Management Profile for Tasmania's Threatened Species Link (Threatened Species Section (TSS), 2014vz) [State Action Plan].
State Listing Status
NT: Listed as Vulnerable (Territory Parks and Wildlife Conservation Act 2000 (Northern Territory): 2012 list)
QLD: Listed as Vulnerable (Nature Conservation Act 1992 (Queensland): May 2014 list)
TAS: Listed as Vulnerable (Threatened Species Protection Act 1995 (Tasmania): September 2012 list)
WA: Listed as Vulnerable (Wildlife Conservation Act 1950 (Western Australia): September 2013 list)
Non-statutory Listing Status
IUCN: Listed as Critically Endangered (Global Status: IUCN Red List of Threatened Species: 2013.1 list)
Scientific name Eretmochelys imbricata [1766]
Family Cheloniidae:Testudines:Reptilia:Chordata:Animalia
Species author (Linnaeus,1766)
Infraspecies author  
Reference  
Distribution map Species Distribution Map

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

Illustrations Google Images

The current conservation status of the Hawksbill Turtle, Eretmochelys imbricata, under Australian Government legislation and international conventions is as follows:

National: Listed as a Vulnerable, Marine and Migratory species under the Environment Protection and Biodiversity Conservation Act 1999.

Scientific name: Eretmochelys imbricata

Common name: Hawksbill Turtle

Hawksbill Turtles have a parrot-like beak. Adults have an olive-green or brown carapace (upper shell) with reddish-brown, brown or black markings in a tortoiseshell pattern. The carapace is highly domed and heart shaped with imbricate (overlapping) scale and is cream to yellowish underneath (Cogger 1994; Limpus 1995a). Adult females weigh 50 kg and have a mean curved carapace length of approximately 82 cm (Dobbs et al. 1999).

Hatchlings are brown to black above and light underneath (Cogger 1994). They weigh around 14 g and have a straight carapace length of approximately 4 cm (Dobbs et al. 1999).

Major nesting of Hawksbill Turtles in Australia occurs at Varanus Island and Rosemary Island in Western Australia (Pendoley 2005), and in the northern Great Barrier Reef and Torres Strait (Dobbs et al. 1999; Limpus et al. 1989), Queensland. The key nesting and inter-nesting areas (where females live between laying successive clutches in the same season) in Australia are (DEH 2005b):

Queensland
Milman Island and the inner Great Barrier Reef Cays north from Cape Grenville
Central Torres Strait islands
Crab Island
Murray Islands
Darnley Island
Woody Island
Red Wallis and Woody Wallis Islands
Bramble Cay and Johnson Islet (Torres Strait)
Western Cape York Peninsula

Northern Territory
Coburg Peninsula
Between Nhulunbuy and northern Blue Mud Bay (East Arnhem Land)
Groote Island
Sir Edward Pellew Islands
Wessel and English Islands

Western Australia
The Dampier Archipelago
The Ningaloo and Jurabi Coasts
Thevenard, Barrow, Lowendal and Montebello Island

In Queensland, Milman Island and the inner Great Barrier Reef Cays north from Cape Grenville are important foraging grounds and juvenile habitat for Hawksbill Turtles (DEH 2005b).

In Western Australia, reefs west of Cape Preston and south to Onslow are important feeding grounds for the species (Pendoley 2005).

The Groote Eylandt appears to be the most significant area for Hawksbill nesting in the Northern Territory (DEWHA 2008).

Hawksbill Turtles are found in tropical, subtropical and temperate waters in all the oceans of the world. Nesting is mainly confined to tropical beaches (Marquez 1990).

The total population of Hawksbill Turtles in Australia is unknown. However, it is known that Australia holds the largest breeding populations of Hawksbill Turtles in the world, and the largest rookeries (nesting aggregations) (Limpus 1995b). Several thousand females nest in Queensland each year. Around 3000 females nest in Western Australia each year (DEH 2005b).

In Australia, there are two genetically separate subpopulations; one in the northern Great Barrier Reef, Torres Strait and Arnhem Land; and the other on the North West Shelf of Western Australia. This genetic distinctiveness means that individuals from the two subpopulations interbreed very rarely (Broderick et al. 1995).

Australian stocks of Hawksbill Turtles are genetically different from the stocks that breed in neighbouring countries such as the Solomon Islands and Malaysia (Moritz et al. 2002).

There have been serious population declines of Hawksbill Turtles worldwide. In Australia, long-term monitoring of nesting turtles at Milman Island in the Torres Strait has shown that the number of Hawksbill Turtles has been declining by 3% to 4% per year for at least ten years. On the northern Great Barrier Reef, the body size of nesting females has decreased, and the hatching success on Raine Island has been poor since 1996 (DEH 2005a).

Hawksbill Turtles occur in the following marine reserves (DEH 2005a). These reserves are managed to protect feeding grounds, nesting grounds and inter-nesting habitat (where females occur during non-breeding times) for marine turtles in Australia, including the Hawksbill Turtle:

Queensland

  • Great Barrier Reef Marine Park
  • Moreton Bay Marine Park
  • Mon Repos Conservation Park
  • Capricornia Cays National Park and Capricornia Cays National Park Scientific
  • Great Sandy National Park
  • Swain Reefs National Park
  • Bushy Island National Park
  • Barubbra Island Conservation Park
  • Mouth of Baffle Creek Conservation Park 1 and 2
  • Mouth of Kolan River Conservation Park
  • Percy Islands National Park
  • Raine Island Nature Refuge
  • Sandbanks National Park
  • Denham Group National Park
  • Saunders Islands National Park
  • Sir Charles Hardy Group National Park
  • Clairmont Isles National Park
  • Howick Group National Park

Western Australia

  • Ashmore and Cartier Nature Reserves
  • Ningaloo Marine Park
  • Shark Bay World Heritage Area
  • Dampier Archipelago Nature Reserve
  • Thevenard Island Nature Reserve
  • Barrow Island Nature Reserve
  • Montebello Conservation Park
  • Cape Range Conservation Park
  • Muiron Islands Nature Reserve

Northern Australia

  • Kakadu National Park
  • Gurig Gunalc Barlu National Park
  • Coburg Marine Park
  • Dhimurru Indigenous Protected Area

Coral Sea Islands Territory

  • Coral Sea National Nature Reserve

Cocos Islands

  • Cocos (Keeling) Islands

Feeding grounds west of Cape Preston and south to Onslow are protected within Sandy Island Nature Reserve (Pendoley 2005).

Hawksbill Turtles spend their first five to ten years drifting on ocean currents (Carr 1987a; Limpus et al. 1994e). During this pelagic (ocean-going) phase, they are often found in association with rafts of Sargassum (a floating marine plant that is also carried by currents) (Carr 1987a).

Once Hawksbill Turtles reach 30 to 40 cm curved carapace length, they settle and forage in tropical tidal and sub-tidal coral and rocky reef habitat. They primarily feed on sponges and algae (Whiting 2000a). They have also been found, though less frequently, within seagrass habitats of coastal waters, as well as the deeper habitats of trawl fisheries (Poiner & Harris 1996; Robins et al. 2002).

Hawksbill Turtles have been seen in temperate regions as far south as northern NSW (Limpus 1992; Robins 2002; Whiting 2000).

Hawksbill Turtles grow very slowly. Growth and timing of sexual maturity vary between populations (Chaloupka & Limpus 1997). Sexual maturity is not reached until after 31 years of age (Limpus 1992).

To develop successfully, marine turtle eggs must be buried in sand that is aerated (but not exposed), low in salt, high in humidity (but not flooded), and between 25° and 33° C (DEH 2005b).

Breeding male and female Hawksbills move from their feeding grounds to areas near nesting beaches for mating. The males then return to their feeding grounds and the females come up onto the beach to lay their eggs, usually on several different nights (Robins et al. 2002). Nesting occurs in the northern Great Barrier Reef and the Torres Strait between January and April (Dobbs et al. 1999; Loop et al. 1995); in the Northern Territory during the second half of the year (Chatto 1997, 1998); and in Western Australia, all year with a peak between October and January (Robinson 1990, cited in Limpus 1995a).

On Milman Island on the northern Great Barrier Reef, Hawksbill Turtles lay between one and six clutches of eggs per season, each with an average of 122 eggs. The inter-nesting interval (the time between successive clutches) is 14.5 days. Individual females reproduce every two to four years (Dobbs et al. 1999). The sex of the hatchlings is determined by the temperature of the nest; warmer nests (above 29° C) produce more females than males (Mrosovsky et al. 1992).

In the Caribbean, Hawksbill Turtles mainly eat sponges (Meylan 1984, 1988). In Australia and elsewhere, they are omnivorous, eating a variety of animals and plants including sponges, hydroids, cephalopods (octopus and squid), gastropods (marine snails), cnidarians (jellyfish), seagrass and algae (Carr & Stancyk 1975; Whiting 2000a). During their pelagic phase (while drifting on ocean currents), young Hawksbill Turtles eat plankton (Meylan 1984).

The Hawksbill Turtle migrates up to 2400 km between foraging areas and nesting beaches (Miller et al. 1998). The recovery of flipper tags suggests that Hawksbill Turtles are highly migratory, as animals that were tagged in the northern Great Barrier Reef have been recaptured in foraging areas in the southern Gulf of Carpentaria, south-eastern Indonesia and southern Papua New Guinea (Limpus in press, as cited in DEWHA 2008). Individual turtles foraging in the same area do not necessarily take the same migration route (Limpus 1992). Nesting populations in eastern Queensland migrate from the Solomon Islands, Indonesia, Papua New Guinea, and Vanuatu (Miller et al. 1998; Parmenter 1983). Captures of tagged turtles have also shown that individual Hawksbills also move between Papua New Guinea and the Solomon Islands (Vaughan & Spring 1980). Satellite tracking has shown that Hawksbill Turtles nesting on Varanus Island and Rosemary Island in Western Australia feed between 50 km and 450 km from their nesting beaches (Pendoley 2005).

Captures of marked turtles in their foraging habitats at Heron Island in Queensland (Limpus 1992) and Fog Bay in the Northern Territory (Whiting 2000a) indicate that individuals remain in a small area of the reef for many years.

Hatchlings swim actively out to sea, and are then carried passively by currents during their pelagic phase. Juvenile Hawksbill Turtles must swim long distances against the current to get back to the reef habitats where they live as adults (Luschi et al. 2003).

Distinctiveness:
The tracks of Hawksbill Turtles, Green Turtles and Flatback Turtles are distinguishable from one another. Hawksbill Turtles have front flipper marks equal or slightly wider than back flipper marks, back flipper marks widely spaced and curled, and the back flippers, belly and tail produce a zigzag pattern due to the turtle's alternating gait. Green turtle tracks have front flipper marks overlapping those made by the back flippers, paired, symmetrical front flipper marks, and a short distance between flipper marks. Flatbacks have only a slight overlap between front and back flipper marks, a straight central line in the sand from dragging the tail tip, and a broad central belly mark (Pendoley 2005).

Recommended methods:
Marine Turtles are generally surveyed during the nesting season, when they emerge from the sea at night (DEH 2005b).

In Australia, the main current threats to Hawksbill Turtles are disturbance and habitat damage due to coastal development; by-catch from fisheries and shark control; predation on nests; boat strikes; entanglement and ingestion of marine debris; and unsustainable levels of indigenous harvest in some areas. Potential threats include climate change, chance disasters (e.g. oil spills) and feral predator invasions (DEH 2005a; Environment Australia 2003ai).

Disturbance of hatchlings by artificial lights
Hatchling Sea Turtles emerge from their nests at night and are attracted to the brighter, lower elevation sea horizon and away from shadows from dunes and vegetation. Hatchlings that move towards artificial lights instead of the sea are likely to be killed by predators or exposure, or burned if they are attracted to fire (Pendoley 2005).

A study on the impact of artificial lights on turtles nesting on Barrow Island, the Lowendal Islands and the Montebello Islands complex on the North West Shelf of Western Australia confirmed that sea turtle hatchlings can see ultraviolet and visible light, and respond most strongly to short wavelengths (blue and green) (Pendoley 2005). The threat to hatchlings from light depends on its wavelength and strength, and the amount of moonlight. Hawksbill Turtle hatchlings are generally attracted to sources of light that are 100 to 200 m away from the nest, and generally moved towards the ocean if the lights were 500 to 800 m away. 500 Watt lights of all types affect hatchlings at a distance of 200 m. Hatchlings were found to be attracted to short-wavelength lights at lower light intensities than to high pressure sodium vapour lights (e.g. streetlights, which emit yellow-orange light) and gas flares (open flames that burn excess gas, emitting mainly long wavelengths). Single 250 W sodium vapour lights that are 200 m away or further have no detectable effect, while 500 W fluorescent lights can attract hatchlings at a distance of 800 m. Some distant offshore lights from pearling vessels and drilling rigs (for example an offshore drilling rig 3.3 km away) were bright enough to affect hatchling movements. Oil and gas processing facilities and offshore vessels on the North West Shelf use mercury vapour, metal halide and fluorescent lamps that emit light concentrated in the short wavelength range that attracts hatchling turtles. On moonlit nights, hatchlings will selectively move to the ocean rather than to gas flares, but flares may attracted them on moonless nights (Pendoley 2005).

Other aspects of coastal development and industry
Hawksbill Turtles migrate close to the ocean surface along the coast and in shipping channels between their breeding and feeding grounds. In eastern Queensland, at least 65 turtles were killed between 1999 and 2002 when they were hit by vessels, a mortality risk comparable to that of trawling without Turtle Excluder Devices in the region. However, Hawksbills are not as frequently struck by boats in Queensland as some other species of turtles (Hazel & Gyuris 2006). The Dampier Archipelago in Western Australia is an important migration route for Hawksbill Turtles and one of the busiest ports in Australia. Migratory pathways north of the Dampier Archipelago are unprotected by conservation reserves, as are those between Scott Reef and the Joseph Bonaparte Gulf in the Northern Territory. Turtles may also be harmed by seismic discharges during mining and exploration, and habitat damage as a result of pipeline installation, dredging and construction (Pendoley 2005).

Disruptions to nesting beaches can prevent females nesting and can kill hatchlings. Disruptions include erosion and erosion control measures such as drift fencing, rubbish, recreational vehicles, shoreline developments, marina and jetty developments, beach cleaning, sand compaction and beach nourishment (adding sand) (Robins et al. 2002; US Fish & Wildlife Service 1999).

By-catch
Trawling is responsible for more sea turtle deaths than any other human-related factor (Bisong 2000). In the late 1980s, 5000 to 6000 sea turtles were caught each year as by-catch in the Australian Northern Prawn Fishery (off the north coast of Australia), with a mortality rate of up to 39% (14% from drowning in the net, and 25% from injury or drowning after being returned to the ocean comatose) (Poiner & Harris 1996). Around 2% of turtles caught in the Northern Prawn Fishery are Hawksbills (Robins et al. 2002). Robins (1995) found that around 5300 turtles are caught in the Queensland East Coast Prawn Fishery each year. Only 1% to 7% of these turtles die, because the duration of trawls is generally short enough not to drown them (less than 80 minutes). The use of Turtle Excluder Devices (TEDs) was made compulsory in Queensland in 1999, and in the Australian Northern Prawn Fishery in 2000. Before TEDs were introduced, an average of 0.24 turtles were caught per Banana Prawn trawl, and 0.30 turtles per Tiger Prawn trawl. Since the introduction, the capture rate has dropped to 0.007 and 0.009 turtles per Banana Prawn and Tiger Prawn trawl respectively. Some turtles are still caught because the TED becomes blocked (e.g. with starfish), small turtles pass through it, or the net is winched up before the turtle has reached the TED. Turtles are also caught in the 'try gear' (small trawls to sample prawn density before the main trawl, and not fitted with TEDs), but the duration of these captures is short and unlikely to drown them (Robins et al. 2002).

Substantial numbers of turtles die during pound netting, gill-netting, purse seine netting and lobster and crab pot trapping, because they are hooked or become entangled in lines. The Australian Tuna and Billfish Longline Fisheries also catch around 400 turtles per year, but very few are Hawksbills (DEH 2005b). Shark nets and hook lines around swimming beaches also kill turtles (Robins et al. 2002). Between 1962 and 1998, the Queensland Shark Control Program caught 4300 turtles and about 20% died before release (DEH 2005b).

Predation
Large numbers of Hawksbill Turtle eggs are eaten by dingos and goannas in the Northern Territory and Queensland. Feral pigs destroy nests in Queensland (Environment Australia 1998b).

Marine debris and pollution
Eating discarded plastic or other debris (e.g. plastic bags, styrofoam beads, packing tape and rope fragments) can cause internal blockage, ulcers, poisoning and suffocation in Hawksbill Turtles. Turtles may also be injured or killed if they become entangled in debris. Oil and tar on beaches and on the water surface can choke or poison turtles, or inhibit swimming. Other potentially harmful pollutants include pesticides, heavy metals, organochlorides, and sewage from the land or from boats. These can pollute feeding grounds and increase disease in turtles (Robins et al. 2002). Floating debris particularly affects juvenile turtles, because they spend their first years drifting in convergences (rips, fronts and driftlines formed by ocean currents). Debris and young turtles are both drawn into these convergences by down-wellings in the open ocean (Carr 1987a).

Discarded fishing nets ('ghost fishing') are responsible for a substantial number of deaths of turtles in Australia (Chatto et al. 1995; Guinea & Chatto 1992). Ghost nets are an especially serious problem in the Gulf of Carpentaria, where currents draw them in from the north then circulate them indefinitely. A study in 2005 found around 170 kg of marine debris per kilometre of coast, including more than 400 ghost nets over the whole area. Hawksbill Turtles are one of the most frequently caught species in ghost nets (DEH 2005b; White 2005, as cited in DEH 2005b).

Changing temperature of nesting beaches and the marine habitat
In Hawksbill Turtles, the temperature of the nest affects the sex ratio of hatchlings. Cooler, more shaded beaches produce more males, while warmer, sunny beaches produce more females. Beaches are heated by clearing of coastal forest, importing heat-absorbing sand for 'beach nourishment' in tourist areas, and global climate change. These changes can result in female-biased populations. Human alteration to the temperature of nest sites can also increase parasites and diseases in the eggs and make some beaches unsuitable for nesting (DEH 2005b; US Fish & Wildlife Service 1999). Climate change scenarios predict reduced nesting habitat for sea turtles through rising sea levels and increased storm erosion. Changing ocean circulation may disrupt the ocean-going phase of juvenile sea turtles, and the predicted increased coral bleaching and burning of seagrass habitats will reduce their food resources (DEH 2005b). Sea surface temperature also has major effects on the frequency of sea turtle breeding (Solow et al. 2002).

Hunting
Hawksbill Turtles are hunted for food and for their shell, which is used to make tortoiseshell (bekko) objects (Limpus 1998). Indigenous harvest of adults, juveniles and eggs is substantial in northern Australia and neighboring countries. Hunting and egg collection have depleted populations of Hawksbill Turtles in Indonesia, Malaysia, Thailand, Philippines, Cuba and the Solomon Islands (Limpus 1995b). There are serious concerns that the collective indigenous harvest of these species within the Eastern marine region is not sustainable (DEW 2007a).

Reducing bycatch and harm to marine turtles

No commercial harvesting of sea turtles is permitted in Australia (DEH 2005b). The Queensland Commercial Fisherman's Organisation, the Queensland Department of Primary Industries, the Australian Fisheries Research and Development Corporation, and the Australian Nature Conservation Agency have together published a code of fishing ethics regarding the accidental capture of sea turtles (Robins et al. 2002). The recommendations of this code include:

  • Not trawling within two to three nautical miles of major nesting beaches during the turtle nesting season.
  • Limiting the duration of trawls to less than 90 minutes in areas with high turtle numbers to minimise the number of netted turtles that drown.
  • If turtles are caught, handling live and active individuals gently, and returning them to the water as soon as possible. Applying the recommended recovery procedure to comatose turtles.
  • Participating in research programs on the incidental capture rate and the effectiveness of turtle excluder devices, and forwarding information on any tagged turtles caught to the Queensland Southern Fisheries Centre.

Shorter trawls reduce the chance of turtles drowning and being injured, and Turtle Excluder Devices reduce the number of turtles caught. Since the use of Turtle Excluder Devices was made compulsory in the Australian Northern Prawn Fishery in 2000, the catch of sea turtles has declined from around 5000 to around 200 per year. The death rate of captured turtles has also nearly halved, from around 40% to 22%, because of improved turtle handling procedures and the fact that most turtles are now caught when the net is winched up, and spend little time in the net (Robins et al. 2002).

A recovery procedure has been developed to revive sea turtles that have been caught in nets and brought on board in a comatose state. Comatose turtles (which appear to be lifeless and not breathing) will drown if returned to the water. They may recover if the rear flippers are raised about 20% off the deck, and the turtle is supported, kept damp and shaded for 24 hours. This allows water to drain from the lungs. A 'turtle recovery procedure' brochure published by the Queensland Commercial Fisherman's Organisation and the Queensland Department of Primary Industry explains how to do this. A modification of the procedure involves placing a small plastic pipe into the turtle's windpipe and blowing gently. Around half of the turtles tested with this technique when they appeared to be dead recovered (Robins et al. 2002).

Commonwealth By-catch Action Plans state that the catch of marine turtles must be reported, and By-catch Reduction Devices (e.g. Turtle Excluder Devices) must be used. By-catch Action Plans have been developed for the following fisheries (DEH 2005b):

  • Australia's Tuna and Billfish Longline and minor line fisheries
  • Northern Prawn Fishery
  • Torres Strait Prawn Fishery

In Western Australia, By-catch Action Plans have also been developed for the following fisheries:

  • Shark Bay Scallop Fishery
  • Shark Bay Prawn Fishery
  • Exmouth Gulf Prawn Fishery
  • Nickol Bay Prawn Fishery
  • Onslow Prawn Fishery
  • Kimberley Prawn Fishery
  • Broome Prawn Fishery
  • Abrolhos Islands and Mid-West Trawl Fishery

In Australia, longline fishermen have been issued with de-hooking devices to release turtles that have been hooked in the mouth with minimum injury (DEH 2005b). Changing the size and shape of longline hooks, and the type of bait can reduce turtle by-catch while still being commercially viable. For example, 4.9 cm circle hooks baited with fish caught fewer turtles than 4 cm J-shaped hooks in one longline fishery in the Atlantic Ocean. Turtles that were caught were also less likely to swallow the hooks (they were hooked in the mouth instead).

Other strategies being assessed that might reduce turtle by-catch are:

  • Submerging hooks more deeply.
  • Retrieving lines faster from the water during the day.
  • Avoiding areas with the greatest risk of by-catch through communication programmes.
  • Seasonal fishery closures (Gilman et al. 2006).

Many traditional owner groups, community rangers, and Native Title representative organisations in Northern Australia are involved in projects to assess and reduce marine debris. These include the Dhimurru Land Management Aboriginal Corporation of the Gulf of Carpentaria, and more than ten other communities in the Gulf of Carpentaria and Torres Strait (DEH 2005a, b).

Gnaraloo Station Feral animal control has been implemented along the Gnaraloo coast (which is part of Ningaloo Reef) each season between 2008/09 and 2011/12. The program targeted Foxes, Cats and Dogs with 1080 baiting immediately behind coastal rookeries, in surrounding hinterland, beaches adjacent to the rookeries and general targeted baiting in the remainder of Gnaraloo Station (i.e. around water sources) (Butcher & Hattingh 2012). In 2011/12, this program achieved zero mortalities from animal predation (Butcher & Hattingh 2012). It is recommended that the program continues in the future, with annual baiting during the turtle breeding season (November-April) and prior to the fox breeding season (May) (Butcher 2008, 2009, 2009a, 2010, 2011; Butcher & Hattingh 2012).

Artificial Lights
Pendoley (2005) recommended the following methods to reduce harm to turtle hatchlings from light pollution:

  • Replacing short-wavelength lights with longer wavelength lights.
  • Shielding, lowering or directing light sources onto work areas.
  • Filtering existing lights to increase the wavelength (e.g. encasing fluorescent lights in yellow filter material).
  • Relocating lights away from nesting beaches.
  • Painting equipment and vessels with dark, non-reflective paint to reduce light reflected into the sky.
  • Embedding street lighting.
  • Using motion sensors or timers in the vicinity of turtle nesting beaches so that lights are not constantly turned on.

Limpus (2002) proposed a 1.5 km buffer zone to protect sea turtle hatchlings from artificial lights.

Embedding light-emitting diodes in the roadway pavement instead of using overhead lighting near turtle nesting beaches has been found to be effective (Bertilotti & Salmon 2005).

Reducing egg and hatchling loss
Fox baiting near Hawksbill rookeries (nesting aggregations) at North-west Cape, Western Australia, has reduced nest predation by more than 90% (DEH 2005b). Protective cages over nests are sometimes used, however galvanized steel cages are magnetic and could alter turtles' subsequent ability to navigate back to their nesting beach as adults (Irwin et al. 2004). Therefore, the use of non-magnetic materials is recommended (Irwin et al. 2004).

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 Hawksbill Turtle has been identified as a conservation value in the Temperate East (DSEWPaC 2012aa), 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 hawksbill turtle in the North-west (DSEWPaC 2012y) and North (DSEWPaC 2012x) 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), North (DSEWPaC 2012x) and Temperate East (DSEWPaC 2012aa) marine regions provide additional information.

The following three management plans provide guides to threat abatement, conservation and research strategies for the Hawksbill Turtle:

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:Indigenous hunting and harvesting Feedback on Draft Inventory of Nationally Significant Environmental Assets (NRM region, 2007) [Paper File].
Biological Resource Use:Fishing and Harvesting Aquatic Resources:Mortality due to capture, entanglement/drowning in nets and fishing lines 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 (Department of the Environment and Heritage, 2005b) [Recovery Plan].
Biological Resource Use:Fishing and Harvesting Aquatic Resources:Overfishing, competition with fishing operations and overfishing of prey fishing Eretmochelys imbricata in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006ih) [Internet].
Climate Change and Severe Weather:Sea level rise:Inundation associated with climate change 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 (Department of the Environment and Heritage, 2005b) [Recovery Plan].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation Felis catus (Cat, House Cat, Domestic Cat) Feedback on Draft Inventory of Nationally Significant Environmental Assets (NRM region, 2007) [Paper File].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation Canis lupus familiaris (Domestic Dog) Feedback on Draft Inventory of Nationally Significant Environmental Assets (NRM region, 2007) [Paper File].
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Grazing, tramping, competition and/or habitat degradation Sus scrofa (Pig) Eretmochelys imbricata in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006ih) [Internet].
Draft Recovery Plan for Marine Turtles in Australia (Env. Aust, 1998) [Recovery Plan].
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:Competition and/or predation Canis lupus dingo (Dingo, Warrigal, New Guinea Singing Dog) Eretmochelys imbricata in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006ih) [Internet].
Invasive and Other Problematic Species and Genes:Problematic Native Species:Competition and/or predation by birds Eretmochelys imbricata in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006ih) [Internet].
Invasive and Other Problematic Species and Genes:Problematic Native Species:Predation by reptiles Eretmochelys imbricata in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006ih) [Internet].
Pollution:Garbage and Solid Waste:Ingestion and entanglement with marine debris Eretmochelys imbricata in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage (DEH), 2006ih) [Internet].

Bisong, S. (2000). The WTO Panel decision on the US shrimp embargo: Another ruling against US enforcement of species protection in trade. Natural Resources Journal. 40:699-726.

Broderick, D., C. Moritz, J.D. Miller, M. Guinea, R.I.T. Prince & C.J. Limpus (1995). Genetic studies of the hawksbill turtle Eretmochelys imbricata: evidence for multiple stocks in Australian waters. Pacific Conservation Biology. 1:123-132.

Butcher, M. (2008). Fox Control Program for Gnaraloo Station. Turtle Predation Minimisation Project (For turtle breeding season 2008/09). December 2008. [Online]. Animal Pest Management Services. Available from: http://www.gnaraloo.com.au.

Butcher, M. (2009). Fox Management Project. Technical Report for Gnaraloo (For turtle breeding season 2009/10). November 2009. [Online]. Animal Pest Management Services. Available from: http://www.gnaraloo.com.au.

Butcher, M. (2009a). Fox Control Program for Gnaraloo Station. Turtle Predation Minimisation Project (For turtle breeding season 2008/09). January 2009. [Online]. Animal Pest Management Services. Available from: http://www.gnaraloo.com.au.

Butcher, M. (2010). Fox Control Program for Gnaraloo Station. Turtle Predation Minimisation Project (For turtle breeding season 2009/10). February 2010. [Online]. Animal Pest Management Services. Available from: http://www.gnaraloo.com.au.

Butcher, M. (2011). Gnaraloo Fox Control Program. Report 2010/11, Protection of sea turtle rookeries on the Gnaraloo coast. June 2011. [Online]. Animal Pest Management Services. Available from: http://www.gnaraloo.com.au.

Butcher, M. & K. Hattingh (2012). Gnaraloo Feral Animal Control Program. Final Report 2011/12. 30 June 2012. [Online]. Animal Pest Management Services and Gnaraloo Station Trust, Western Australia. Available from: http://www.gnaraloo.com.au.

Carr, A. (1987a). Impact of nondegradable marine debris on the ecology and survival outlook of sea turtles. Marine Pollution Bulletin. 18(6b):352-356.

Carr, A. & S. Stancyk (1975). Observations on the ecology and survival outlook of the Hawksbill Turtle. Biological Conservation. 8:161-172.

Chaloupka, M.Y. & C.J. Limpus (1997). Robust statistical modelling of hawksbill sea-turtle growth rates (Southern Great Barrier Reef). Marine Ecology Progress Series. 146:1-8.

Chatto, R. (1997). Marine turtles in the Northern Territory: a brief overview of nesting. In: Noor, Y. R., I. R. Lubis, R. Ounsted, S. Troeng, & A. Abdullah, eds. Proceedings of the Workshop on Marine Turtle Research and Management in Indonesia. Bogor, Wetlands International /PHPA/ Env. Aust.

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

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

Department of Environment and Heritage (2005b). 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]. Commonwealth Department of Environment and Heritage: Canberra. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/recovery/marine-turtles/pubs/issues-paper.pdf. [Accessed: 02-Oct-2007].

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 and Water Resources (DEW) (2007a). Draft East Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the East Marine Region.

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.

Dobbs, K.A., J.D. Miller, C.J. Limpus & A.M.Landrey Jr (1999). Hawksbill turtle, Eretmochelys imbricata, nesting at Milman Island, northern Great Barrier Reef, Australia. Chelonian Conservation and Biology. 3(2):344-361.

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 (1998b). Draft Recovery Plan for Marine Turtles in Australia. Environment Australia: Canberra.

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.

Gilman, E., E. Zollett, S. Beverly, H. Nakano, K. Davis, D. Shiode, P. Dalzell & I. Kinan (2006). Reducing sea turtle by-catch in pelagic longline fisheries. Fish and Fisheries. 7(1):2-23.

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

Hazel, J. & E. Gyuris (2006). Vessel-related mortality of sea turtles in Queensland, Australia. Wildlife Research. 33:149-154.

Irwin, W.P., J.H. Amy & K.J. Lohman (2004). Magnetic field distortions produced by protective cages around sea turtle nests: unintended consequences for orientation and navigation?. Biological Conservation. 118:117-120.

Limpus, C.J. (1992). The hawksbill turtle, Eretmochelys imbricata, in Queensland: population structure within a southern Great Barrier Reef feeding ground. Wildlife Research. 19(4):489-506.

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

Limpus, C.J. (1995b). Global overview of the status of marine turtles: a 1995 viewpoint. In: Bjorndal, KA, ed. Biology and Conservation of Sea Turtles. Revised edition. Washington, Smithsonian Institution Press.

Limpus, C.J. (1998). Overview of Marine turtle conservation and management in Australia. In: Kennett, R., A. Webb, G. Duff, M. Guinea & G. Hill, eds. Marine conservation and management in Northern Australia. Proceedings of a workshop held at the Northern Territory University, Darwin, June 1997.

Limpus, C.J. (2002). Western Australian Marine Turtle Review. Queensland Environmental Protection Agency: Brisbane.

Limpus, C.J. & J.D. Miller (2000). Australian Hawksbill Turtle Population Dynamics Project. [Online]. Brisbane, Queensland Environmental Protection Agency. Available from: http://www.epa.qld.gov.au/publications/p02427aa.pdf/Australian_Hawksbill_Turtle_Population_Dynamics_Project.pdf.

Limpus, C.J., D. Zeller, D. Kwan & W. Macfarlane (1989). Sea-turtle rookeries in northwestern Torres Strait (Australia). Australian Wildlife Research. 16(5):517-526.

Limpus, C.J., T.A. Walker & J. West (1994e). Post-hatchling sea turtle specimens and records from the Australian region. In: James, R., ed. Proceedings of the Australian Marine Turtle Conservation Workshop, Gold Coast 14-17 November 1990. Page(s) 95-100. Canberra, ANCA.

Loop, K.A., J.D. Miller & C.J. Limpus (1995). Nesting by the hawksbill turtle (Eretmochelys imbricata) on Milman Island, Great Barrier Reef, Australia. Wildlife Research. 22:241-252.

Luschi, P., G.C. Hays & F. Papi (2003). A review of long-distance movements by marine turtles, and the possible role of ocean currents. Oikos. 103:293-302.

Marquez, R. (1990). FAO Species Catalogue; Sea Turtles of the World. An annotated and illustrated catalogue of the sea turtle species known to date. FAO Fisheries Synopsis. 125 (11):pp 81. Rome: Food and Agriculture Organisation of United Nations.

Meylan, A. (1988). Spongivory in hawksbill turtles: a diet of glass. Science. 239:393-395.

Meylan, A.B. (1984). Feeding ecology of the Hawksbill Turtle (Eretmochelys imbricata): spongivory as a feeding niche in the Coral Reef Community. Ph.D. Thesis. Gainsville, University of Florida.

Miller, J.D., K.A. Dobbs, C.J. Limpus, N. Mattocks & A.M. Landry Jr (1998). Long-distance migrations by the hawksbill turtle, Eretmochelys imbricata, from north-eastern Australia. Wildlife Research. 25:89-95.

Moritz, C., D. Broderick, K. Dethmers, N. FitzSimmons & C. Limpus (2002). Population Genetics of Southeast Asian and Western Pacific Green Turtles, Chelonia mydas. Unpublished Report to United Nations Environment Programme. CMS, Bonn, Germany.

Mrosovsky, N., A. Bass, L.A. Corliss, J.I. Richardson & T.H. Richardson (1992). Pivotal and beach temperatures for hawksbill turtles nesting in Antigua. Canadian Journal of Zoology. 70:1920-1925.

Northern Prawn Fishery Management Advisory Committee (2003). Northern Prawn Fishery Bycatch Action Plan. [Online]. Available from: http://www.afma.gov.au/information/publications/fishery/baps/docs/npfbap03.pdf. [Accessed: 10-Jul-2007].

Parmenter, C.J. (1983). Reproductive migration in the hawksbill turtle (Eretmochelys imbricata). Copeia. 1983:137-163.

Pendoley, K.L. (2005). Sea turtles and the environmental management of industrial activities in north-west Western Australia. Ph.D. Thesis. PhD Thesis, Murdoch University: Perth.

Poiner, I.R. & A.N.M. Harris (1996). Incidental capture, direct mortality and delayed mortality of sea turtles in Australia's northern prawn fishery. Marine Biology. 125:813-825.

Robins, C.M., A.M. Goodspeed, I. Poiner & B.D. Harch (2002). Monitoring the catch of turtles in the Northern Prawn Fishery. Fisheries Research and Development Corporation. Department of Agriculture, Fisheries & Forestry: Canberra.

Robins, J.B. (1995). Estimated catch and mortality of sea turtles from the East Coast Otter Trawl Fishery of Queensland, Australia. Biological Conservation. 74:157-167.

Solow, A.R., K.A. Bjorndal & A.B. Bolten (2002). Annual variation in nesting numbers of marine turtles: the effect of sea surface temperature on re-migration intervals. Ecology Letters. 5:742-746.

United States Fish & Wildlife Service (1999). Hawksbill Sea Turtle. Multi-species recovery plan for South Florida: a species plan, an ecosystem approach. [Online]. Available from: http://www.fws.gov/southeast/vbpdfs/species/reptiles/hstu.pdf. [Accessed: 10-Jul-2007].

Vaughan, P. & S. Spring (1980). Long distance hawksbill recovery. Marine Turtle Newsletter. 16:6-Jul.

Whiting, S.D. (2000a). The ecology of immature Green and Hawksbill Turtles foraging two reef systems in north-western Australia. Page(s) 370. Ph.D. Thesis. Darwin, Northern Territory University.

EPBC Act email updates can be received via the Communities for Communities newsletter and the EPBC Act newsletter.

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

Citation: Department of the Environment (2014). Eretmochelys imbricata in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Wed, 3 Sep 2014 00:14:53 +1000.