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 Endangered as Elusor macrurus|
|Listing and Conservation Advices||
Commonwealth Conservation Advice on Elusor macrurus (Mary River Turtle) (Threatened Species Scientific Committee, 2008ac) [Conservation Advice].
|Recovery Plan Decision||
Recovery Plan not required, included on the Not Commenced List (1/11/2009).
|Adopted/Made Recovery Plans|
|Policy Statements and Guidelines||
Survey guidelines for Australia's threatened reptiles. EPBC Act survey guidelines 6.6
(Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2011m) [Admin Guideline].
Federal Register of
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 Elusor macruros.
Amendment to the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (11/04/2007) (Commonwealth of Australia, 2007f) [Legislative Instrument] as Elusor macrurus.
|State Listing Status||
|Non-statutory Listing Status||
|Scientific name||Elusor macrurus |
|Species author||Cann and Legler, 1994|
Elusior macruros 
Elusor macruros 
This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.
Scientific name: Elusor macrurus
Common name: Mary River Turtle
Other common name: Mary River Tortoise
Between 1970 and 1990, the Mary River Tortoise was known only from the pet trade. Eggs were sold to pet shops under the name Elseya latisternum, the Common Saw-shelled Turtle (Georges 1995), and hatchlings were known as the 'Penny Turtle' (Australian Museum 2006). The species was known as 'short-neck alpha' by turtle biologists and was not formally described, because pet traders refused to reveal their source of supply. Legal trade in turtles in Queensland ceased in 1974, but turtle researchers continued to search for the location of the turtle in the wild for a further 25 years (Georges 1995). The species was discovered at a property on the Mary River by John Cann, who collected four adults in late 1990, and the Mary River Tortoise was formally described as a new genus and species in 1994 (Australian Museum 2006; Cann & Legler 1994).
The Mary River Tortoise is dark brown, rusty red-brown to almost black above, with a greyish underbody, a broadly oval shell with a median notch, and a moderately sized plastron (the lower half of the shell) which is about twice as long as broad (Cogger 2000; Thomson et al. 2006). The plastron may be cream to yellow, the skin of the inguinal areas pinkish-white, and the dorsal skin grey, suffused with pink on the transverse lamellae scales (Flakus 2002). The species also has pointed tubercles (small, rounded protuberances on the skin) on the neck. Unlike most Australian freshwater turtles (Berry & Shine 1979), males are larger than females. Females grow to 34 cm long, and males to 42 cm long. The shells of females are wider at the front than at the back, and the shells of males are narrow and straight-sided. Tails of males are very long and laterally compressed (Cogger 2000). The carapace (upper shell) of adult males is generally longer than 35 cm, and the tail is longer than 7 cm. This species displays physiological features that allow for cloacal respiration (it has bursae, which are structures like gills in its cloaca, with which it can obtain some oxygen from the water) (Flakus 2002). It has large hind feet, and is a fast swimmer (Thomson et al. 2006).
Eggs are elliptical and have flexible shells (Cann & Legler 1994). On average, they measure 3.5 cm x 2.26 cm and weigh 11.6 ± 1.2 g (Flakus 2002). Hatchlings are 3.3 ± 0.05 cm long on average (range 3.2 to 3.4 cm), and weigh 6.8 g (range 6.1 to 7.5 g) (Flakus 2002). Hatchlings up to three weeks old are dark olive to almost black on the back, flecked with fawn, and have a pale bluish-grey plastron with pale grey skin, suffused with pink. They have a smooth shell. After three weeks, juveniles become lighter coloured, and they have dark smudges or mottling on the inframarginal surfaces (Cann & Legler 1994; Flakus 2002).
The Mary River Tortoise is endemic to the Mary River in south-eastern Queensland. It occurs from Kenilworth, 262.8 km from the mouth of the river, to the area upstream of the Mary River Tidal Barrage at Tiaro, which is 59.3 km from the mouth of the river (Cogger et al. 1993; Cann & Legler 1994; Cann 1998; Flakus 2002). In 1999, the known range was from 78 to 270 km from the mouth of the Mary River, at altitudes from 40 to 120 m (Tucker et al. 1999). Populations are known to occur in major tributaries and the main channel of the Mary River including Yabba and Tinana Creeks, Gunalda, Miva and Tiaro (Hauser et al. 1992; Cogger et al. 1993; Cann & Legler 1994; Cann 1998; Flakus 2002).
Flakus (2002) located the Mary River Tortoise at Gunalda, 140 to 145 km from the river mouth; Woolooga Bridge Crossing near the junction of Munna Creek, 112 km from the river mouth; and Tiaro, 88 km from the river mouth. Tucker et al. (1999) recorded the species upstream of Tallegalla Weir on Tinana Creek, at Imbil Weir on Yabba Creek, and at Kenilworth Bridge on the main channel of the Mary River. Eggs of the Mary River Tortoise were formerly collected between Bell's bridge and Tiaro on the main channel of the Mary River.
The Mary River Tortoise has been inadequately surveyed in the upper reaches of the Mary River, and the limits of its distribution in tributaries are not known (Flakus 2002; Thomson et al. 2006).
The Mary River Tortoise has been inadequately surveyed in the upper reaches of the Mary River, and the limits of its distribution in tributaries are not known (Flakus 2002; Thomson et al. 2006).
The population density of the Mary River Tortoise is lower than that of some other turtles in the Mary River (Elseya sp. and Emydura krefftii). The species constituted 14% of turtles captured during systematic population monitoring by Flakus (2002). Cann (1998) suggested that this species may be rare throughout its known range.
There has been a reduction in the population of breeding female Mary River Tortoises of around 95% between 1970 and 2000. Hundreds of females nested near Tiaro in the 1960s and 1970s, and only ten individuals nested on the same sand banks in 1998 and 1999 (Cann 1998; Flakus 2002; Tucker 1999).
The Mary River flows for around 250 km from its source in the Conondale Range to the sea. Around ten percent of the land area of the catchment is natural vegetation. In 2002, the river system contained 11 water storages, and most barriers to turtle movement were on tributaries. Water infrastructure on the Mary River itself is limited to the Gympie Control Weir, a small weir 179.5 km from the river mouth that is regularly inundated by flows, and the Mary River tidal barrage at Tiaro, 59 km upstream from the river mouth (Kind 2002).
Like other turtles with cloacal respiration, the Mary River Tortoise occurs in flowing, well-oxygenated sections of streams. Its habitat consists of riffles (particularly productive parts of a river that are shallow with fast-flowing, aerated water) and shallow stretches alternating with deeper, flowing pools. It generally does not occur in impoundments (Flakus 2002; Tucker et al. 1999). Limited data on juveniles suggest that they occur in rocky areas with sand or gravel on the river bed, in a variety of water depths (S. Flakus pers. comm. 2003) For example, a hatchling was found at a crossing in 10 cm of water by Latta & Latta (2006). Adults are usually found in areas with underwater shelter, such as sparse to dense macrophyte cover, submerged logs and rock crevices. They bask on logs and rocks (Flakus 2002; S. Flakus, pers. comm. 2003). Some turtles have also been captured at sites with little aquatic vegetation or submerged logs (Cann 1998). The species can occur in depths ranging from less than a metre to more than 5 m (S. Flakus pers. comm. 2003).
Habitat of the Mary River Tortoise at Gunalda (140 to 145 km from the river mouth) consists of a chain of pools that are 1 to 4 m deep, shallow pools (less than 2 m deep) with fast-flowing water, interspersed with riffles that are 10 to 50 m wide (Flakus 2002; Flakus & Wright 1999). The river at Gunalda is typically 1 to 2 m deep with a sand and gravel bottom and boulders at the edges. The banks have steep sides and little vegetation, and there is a sandbank used as access for cattle. The water clarity was 2 m or more in 1997 and 1998, but the water was turbid after severe flooding in 1999. Habitat at Woolooga Bridge Crossing is fast flowing pools less than 2 m deep and riffles. The river is 10 to 40 m wide, and has a sand and gravel riverbed with submerged logs and abundant macrophytes at the edges. One bank is steep, and the riparian vegetation cover is 20 to 60%. There are two sand and gravel banks that are used as access for cattle. The water clarity was 5 m or more in 1997 and 1998, but the water was turbid after severe flooding in 1999. Habitat at Tiaro consists of large, slow-flowing pools (more than 6 m deep) which are usually turbid, some riffles, with a sand and silt riverbed, some boulders and undercut banks. There are few macrophytes or submerged logs, and moderate riparian vegetation cover (40 to 60%). Four sand and gravel banks (two with steep sides) are used as nesting sites for turtles, and as access for cattle (Flakus 2002).
Mary River Turtles move upstream during times of high flow or flooding, and positioned themselves in backwaters or eddies until the flow returns to normal, when they return to their usual home ranges (Flakus 2002).
The Mary River Tortoise takes an exceptionally long time to reach maturity. According to population models, the projected age at maturity is around 25 years for females and 30 years for males. The average carapace length at maturity is expected to be 23 cm for females and 31.5cm for males (Tucker et al. 1998; Tucker 2000). Breeding females examined by Flakus (2002) were 27 to 35 cm long, and males in breeding condition were between 29 and 42 cm long. The adult sex ratio is slightly male biased, with 1.28 males for each female (Flakus 2002).
Distribution of nests
Historical records strongly suggest that the Mary River Tortoise is faithful to traditional nest sites that the same females use each year. Nesting is concentrated on a small number of sand banks. For example, up to 2000 eggs each season were collected from four particular nesting sand banks near Tiaro, indicating that more than a hundred females nested on these (Cann 1998; Flakus 2002). Flakus (2002) interviewed the former egg collector who carried out most of the turtle egg harvest from the Mary River when it was legal, between 1962 and 1974. He and his associates searched the area downstream from Gympie for nests of the Mary River Tortoise. None were found near Gympie, and very few between Gympie and Miva. The area upstream of Bell's Bridge was not searched after the initial lack of success in finding nests there. Eggs were only collected from the main channel. Most of the 1200 to 1500 eggs collected each year came from a handful of sandbanks. The most productive one was at Miva, upstream from Dickabram bridge. There were very productive sandbanks on three properties near Tiaro, and another upstream from Gundiah (Emery's bridge). There were some turtle nests found below the bridge at Reibels crossing near Gunalda. Only 100 to 200 eggs were collected from the less productive nesting areas. Flakus (2002) found up to ten individuals nesting on sandbanks near Tiaro between 1997 and 1999. In 2002, Van Kampen et al. (2003) found 36 nests at these major nesting banks at Redbank Road, near Tiaro. They located nests at Cauley's Road Theebine, Paradise Island, near the Mary River Bridge, and opposite the mouth of Slaty Creek. One nest was also found on a small sand bank near Petrie Park, immediately downstream of a narrow section of river with flowing water, but within the impounded area of the Mary River Barrage.
Micheli-Campbell and colleagues (2013) undertook a photography study and found that some females returned to nest at the same locality over consecutive years, whereas others did not; therefore, it is inconclusive whether the species exhibits true nest-site fidelity. Preferred nesting areas were all northerly facing and exposed sites to higher levels of solar radiation than nonpreferred areas with similar soil and physical characteristics. Consequently, the preferred nesting areas exhibited significantly greater mean and daily fluctuations in the nest temperature compared. Warmer nest temperature may speed up embryo development, reduce the embryo incubation period and may reduce exposure to nest predation (Micheli-Campbell et al. 2013).
Conditions required for nesting
Nesting occurs at night when it has recently rained, possibly because moist sand is necessary to dig nests. Females appear to leave the water, test the firmness of the sand, and then return to the water on nights before they dig the nest (Flakus 2002). They dig nests in sparsely vegetated sandy banks, between 1.95 m and 51 m away from the water's edge and on both steep and shallow slopes, either protected or unprotected by vegetation. Nests are placed 2.3 ± 1.3 m above water level, and females dig to a depth of 19.9 ± 1.6 cm (range 17 to 23 cm). Eggs are 11.7 ± 3.7 cm below the surface on average (range 5 to 19 cm) (Flakus 2002; van Kampen et al. 2003). According to a former egg collector interviewed by Flakus (2002), in the past, Mary River Tortoises nested mainly on large, steep sand banks 'up to 200 yards from the water', including at the top of sand banks amongst grass and along cattle tracks. They emerged from the water only over sand banks. He stated that fewer females laid in drought years. Nest temperatures in the wild vary from 26° to 40° C (Flakus 2002), and the species does not have temperature-dependent sex determination (Georges & McInnes 1998).
Rate and timing of breeding
The Mary River Tortoise has a low reproductive rate; each female lays one clutch of 12 to 25 eggs (mean 12.2 ± 3.7) in a season (Cann & Legler 1994; Flakus 2002; van Kampen et al. 2003). Females begin laying in mid October and continue throughout November (Cann 1998; Flakus 2002). Males begin to produce sperm in late autumn, are in peak reproductive condition in spring, and cease sperm production in late summer (Flakus 2002). Natural incubation periods are around 50 days (van Kampen et al. 2003). Hatchlings emerge throughout December and until February. A former egg collector stated that hatching commenced on Christmas eve each year (Flakus 2002).
Adult Mary River Tortoises are mainly herbivorous, but eat some animal matter. Aquatic plants (macrophytes) make up 79% of the diet by weight. The most important plants in the diet are filamentous algae (43% of samples by mass, eaten by 53% of turtles sampled), Vallisneria sp. (17% of samples by mass, eaten by 50% of turtles), and Myriophyllum sp. (11% of samples by mass, eaten by 22% of turtles). They also eat Cabomba caroliniana, Eloda canadensis, Hydrilla verticulata, and Nitella sp. Two percent of the diet consists of terrestrial plants including buds of Forest Redgum Eucalyptus tetricornis, seeds (and fruit) of the Blackbean Castanospermum australe, and seeds (and fruit) of the lilly pilly Waterhousia floribunda. 20% of the diet consists of aquatic insect larvae, particularly caddisfly larvae (Trichoptera), mosquito or midge larvae (Diptera) and moth larvae (Lepidoptera). They occasionally eat freshwater mussels Velesuio ambiguus, and eggs of aquatic animals (unidentified) (Cann & Legler 1998; Flakus 2000; Flakus 2002).
Juvenile Mary River Tortoises eat mainly aquatic insect larvae (53%) including caddisfly larvae (Trichoptera from the families Helicopsychidae and Hydropschidae), mosquito or midge larvae (Diptera), moth larvae (Lepidoptera), beetle larvae (Coleoptera), mayfly larvae (Ephemoptera), scorpionfly larvae (Mecoptera), lacewing larvae (Neuroptera), and drogonfly larvae and nymphs (Odonata) (53% of samples by mass) as well as freshwater sponges (21%) and aquatic plants (25%) (Flakus 2002).
A former egg collector stated that hatchling Mary River Tortoises will only feed in the water (Flakus 2002).
During the non-breeding season, radio-tracking showed that the length of the home range used by the Mary River Tortoise was 200 to 650 m. The average distance moved per day was 192 m. There was no difference in the range or distance moved each day by male and female turtles during the non-breeding season; both moved an average of 137 to 139 m between consecutive locations. Females used an average stretch of 250 m to 2 km, while males used 100 m to 1.1 km.
During the breeding season (October to December), female Mary River Tortoises moved to areas of the river that are adjacent to sand banks for nesting. Females had longer ranges in the breeding season than the non-breeding season, because they moved to and from nesting areas. Sand banks are uncommon on the Mary River, and the average distance travelled by females varied depending on the proximity of a sand bank to the home pool. Three females moved 525 m, 475 m and 783 m respectively to their nesting areas. Females therefore used two core areas of activity each year; one near a nesting bank and the other in a pool where the turtle resided during the non-breeding season. Males had one core area in a particular pool (Flakus 2002).
Home ranges of radiotracked males and females in the wild did not overlap (Flakus 2002), and captive Mary River Tortoises are reported to be aggressively territorial (Cann 1998).
Mary River Tortoises are more difficult to find and catch in winter than in summer (Flakus 2002).
Predation and lack of recruitment
The Mary River Tortoise has suffered very poor breeding success for three to four decades. Around 12 000 eggs per year were collected commercially from the banks of the Mary River between Tiaro and Gympie for a period of twelve years (1962 to 1974). It is likely that there was little or no recruitment during this time in this stretch of 120 km (around 60% of the known range of the species within the main river channel). After the last laying of each season, collectors dug up entire sand banks throughout the area to make sure that they had not missed any nests (interview with a former egg collector, cited in Flakus 2002). Nesting data collected during the five years up to 2003 in the Tiaro area indicate that there has been a decline of 89% in the number of nests since the 1960s and 1970s (Flakus 2002; van Kampen et al. 2003).
Hatching success in the wild continues to be very low. According to a former egg collector, foxes became much more common in nesting areas after the 1970s (interview cited in Flakus 2002). Predation of nests is now frequent. In 1997, 17% of nests monitored by Flakus (2002) were destroyed by foxes within 24 hours of laying, a further 8% were destroyed by goannas, and eggs in the remaining 75% of nests disappeared, presumably because they were taken illegally by collectors. In 1998, 22% were destroyed by goannas, 33% by unknown agents, and the remaining 45% of nests were removed for artificial incubation, and the nestlings released. In 1999, all nests were destroyed by severe flooding. In 2002, nests were caged the morning after eggs were layed to protect them from predators resulted in around 78% of protected eggs produced hatchlings. A third of nests were flooded, but this was after the estimated hatching date. However, foxes, dogs and goannas had destroyed many of the nests that were not found in time to be caged (van Kampen et al. 2003). Van Kampen et al. (2003) also found evidence that dogs killed some adult tortoises. The size distribution of the Mary River Tortoise indicates that there have been long periods without recruitment. Most of the current population consists of either large adults (28 to 42 cm long), or immatures (9 to 17 cm). Sub-adults and hatchlings are rare. Of 112 captures, only four were sub-adults between 17 and 28 cm long. This is not the case in other species of turtles in the same sections of the Mary River (Flakus 2002).
Dams and weirs
Dams and weirs are poor quality of habitat for the Mary River Tortoise, and this species rarely occurs in impoundments. By surveying species at more than 50 sites in central Queensland catchments, Tucker (1999) showed that impoundments reduce turtle biodiversity relative to the flowing parts of the river, because the Mary River Tortoise and other tortoises that are habitat specialists with slow reproduction are absent from most dams. The larger the impoundment, the more severe this effect is. Reasons why the Mary River Tortoise does poorly in impoundments include:
. The preferred habitat of this species (and of other turtles with cloacal respiration) is flowing water with plenty of dissolved oxygen throughout (Thomson 2006; Tucker 1999). Still water in dams typically has a sharp decrease in oxygen below the top 2 m, and almost no oxygen below 5 m.
. The decline in water quality reduces the time that turtles with cloacal respiration can spend diving for food, and increases exposure of juveniles to predators when they surface frequently to breathe (Priest & Franklin 1999). This is likely to be exacerbated by the lack of protective cover, as macrophyte density is reduced in dams.
. The aquatic insect larvae that juvenile Mary River Tortoises eat rely on shallow riffle habitat, so they are absent or nearly absent from impoundments. Adult tortoises eat mainly macrophytes (water plants), which are severely reduced or lost when impoundments are created and when their water levels fluctuate. Flooding washes away macrophyte beds, and turbid (muddy) flows smother recovering macrophytes. Construction of impoundments results in initial loss of food plants as shallow areas upstream are inundated. For example, Duivenvoorden (1998) reported that macrophytes died and decomposed within six weeks of construction of an impoundment in another river in central Queensland. After the water level upstream became constant, new growth of water plants established after a further six to nine weeks, but these plants died when the water level fluctuated again. Fallen fruit from riverside trees is important in the diet of adult Mary River Tortoises, and these trees are also lost when impoundments are constructed, because fruiting species such as figs, blackbean, and lilly pilly do not tolerate root inundation (Tucker et al. 1999).
Nesting areas of the Mary River Tortoise are lost or reduced in size
through flooding when dams and weirs are built, and conditions in impoundments do not create the sand banks needed for nesting. Some traditional nesting areas were lost or reduced in size when the Tiaro barrage was flooded, including formerly highly productive nesting areas near Petrie Park (interview with a former egg collector, cited in Flakus 2002). Breeding females migrate from their usual home ranges to places that have suitable sand banks for nesting. Unlike other Australian freshwater turtles which often nest in soft soil anywhere near the water, Mary River Tortoises use traditional nesting sites in restricted areas. Therefore, dams and weirs that block access to these nesting sites would severely hinder breeding success and could eventually eliminate local populations (Flakus 2002).
. Flakus (2002) found that Mary River Turtles move upstream to safer sites during floods, to protect themselves from being washed downstream of their home ranges. Dam walls block this movement.
At times of low water storage, overcrowding and disease can affect turtles in impoundments. Tucker (1999) observed high densities of turtles with skin ulcers in a dam that had little water, little food and poor water quality.Van Kampen et al. (2003) suggested that disturbance from water skiing using powered boats within the Mary River Barrage may be one reason for the low abundance of Mary River Tortoises in this impoundment.
Dams can also reduce the water quality downstream, because they often release poorly oxygenated water, increase sediment and cause bank erosion through flow regime changes (Walker 1985). Changed flows can promote aquatic weeds such as water hyacinth and para grass, which choke the waterway, reduce water quality and block the turtle's access to nesting banks over a larger area than the impoundment itself (Tucker 19999).
Turtles can be injured or killed by abrasion and shearing against the spillway face when they pass over the top of dam walls during high water flows. Other species have been observed passing over the tidal barrage on the Burnett River and being unable to return upstream. If Mary River Tortoises are washed into the estuary over the top of the Mary River Barrage, they will be stranded and are likely to be killed by the salt water (Berghuis 2001; Tucker et al. 1999).
Other threats to the habitat
The habitat of the Mary River Tortoise is affected by soil erosion, and soil and water pollution (Cogger et al. 1993; Cann 1998; Flakus 2002). According to John Cann (as cited in Cogger et al. 1993), local residents claim that the nearly constant turbidity of the mid-reaches of the Mary River has only occurred since the 1970s (see also Cann & Legler 1994). Increased siltation and filling of deeper holes may have reduced the area of available habitat (Cogger et al. 1993; Hauser et al. 1992). Habitat loss will decrease the population size of the species, especially because the tortoise shows signs of being territorial (Cann 1998; Flakus 2002). Water quality in the vicinity of Gympie is affected by discharge from a sewerage treatment plant, which increases nutrients and decreases oxygen in the water. Meatworks effluent, pesticide and herbicide runoff also affect the river bank and water quality in sections of the Mary River (EPA 2001).
The Mary River Tortoise is affected by damage to the riverside vegetation and to the structure of the riverbank. The banks of the Mary River are used for sand and gravel mining. There were 13 legal mines and a number of illegal mines in 2002, including a large operation at Tiaro (NRM 2001, as cited in Flakus 2002). Sand mining results in the loss of sand banks, stream bank erosion and siltation of the water, and the industry is prevalent in areas which were formerly the most productive nesting sites of the Mary River Tortoise (Flakus 2002). Much of the vegetation surrounding the lower and middle sections of the Mary River has been cleared for agriculture and cattle grazing (Flakus 2002; Tucker 1999). Nests could be damaged by stock. Cattle trampled all nesting sand banks monitored by Flakus in 1997 and 1998, but in these cases the eggs were buried deep enough to escape damage. Cattle trampling damaged the anti-predator screen over one nest in 2002 (van Kampen et al. 2003).
Weed infestation can cause sand banks to become unsuitable for nesting. For example, one traditional nest site of the Mary River Tortoise at Gunalda, that was known to egg collectors between 1962 and 1974, is now vegetated. Tucker et al. (1999) noted that weeds such as Para Grass Urochloa mutica, Lantana Lantana camara, and Thistles (species in the family Asteraceae) block the access of turtles to nesting banks. Weeds growing on the nesting banks can also kill eggs. Two nests monitored by van Kampen et al. (2003) contained eggs that were penetrated by the roots of couch grass (possibly Cynodon dactylon).
Flakus (2002) stated that the Mary River Tortoise requires urgent action to avoid extinction. She recommended the following specific actions:
- Identification and protection of critical habitat, and involvement of sand mining leases in habitat protection.
- Identification of nesting sites and the range of the species throughout the Mary River catchment.
- Determining its population dynamics, demography (maturity, growth, survival and reproductive cycle), and nesting success.
- Predator control in nesting areas.
- A public awareness program.
- An incubation program to protect eggs from predators and illegal collectors.
- A headstart program to increase hatchling survival and allow recruitment into the population, including moving clutches to safe incubation sites, creating new sandbanks for nesting, re-planting macrophytes after flood scouring, and introducing snags to pools.
van Kampen et al. (2003) recommended baiting to reduce dog and fox abundance during the nesting and hatching period, and the trapping and relocation of goannas found near the nesting banks. Artificial incubation and headstart programs will only work if there is sufficient habitat (i.e. flowing reaches with sand banks) for hatchlings to survive for many decades after they are released (Flakus 2002; Thomson et al. 2006). Tucker et al. (1999) stressed that studies are needed to test if artificially-created habitat is suitable for the species.
Systematic surveys are needed to determine the range of the species, particularly in tributaries, and between Gympie and Conondale in the main channel of the Mary River (Flakus 2002; Thomson et al. 2006).
Tucker et al. (1999) stated that the preferred option for turtle conservation in the Mary River is to keep unimpounded sections of the habitat intact, and to oppose any water resource proposals that cause the middle or core section of unregulated river habitat to be fragmented.
Tucker et al. (1999) recommend manual removal of weeds from nesting banks, because herbicides are pollutants that accumulate in turtles, and should not be used near water.
Greening Australia received $30 000 of funding through the Threatened Species Network Community Grants in 2001 - 2002 for the initiation of conservation and management strategies to save the Mary River turtle. This included protection of nesting sites, artificial incubation of clutches, and collection of data to provide guidance on future turtle conservation.
Greening Australia QLD Inc received $18 000 of funding through the Threatened Species Network Community Grants in 2002 - 2003 to increase egg survivorship and hatchling production by the protection and monitoring of nests over a 34 km stretch of the Mary River, for training of volunteers to help identify turtle tracks and different turtle species, and for the collection of data to enhance future management actions.
The Mary River Catchment Co-ordinating Committee received $15 000 of funding through the Threatened Species Network Community Grants in 2002 - 2003, part of which was for the survey and mapping of threatened species in rainforest areas of the upper Mary River catchment; and the identification, revegetation and rehabilitation of strategic corridor linkages and gaps to reconnect habitat.
Artificial incubation and headstart programs for nestlings
Three clutches of the Mary River Tortoise were taken from nests (without turning the eggs), transported successfully to incubators at Mon Repos, near Bundaberg while refrigerated at 3° to 5° C, then artificially incubated at either 29° or 31° C in sterilised, moistened river sand that was kept damp by regular spraying with water. Ninety-five percent of eggs hatched, after 46 (29°) and 47 days (31°). A former egg collector interviewed stated that incubation success is low if eggs are collected immediately after laying, but eggs collected a week later had 99% hatching success (Flakus 2002). Flakus (2002) noted that female freshwater turtles are susceptible to stress-related inhibition of breeding, and this has occurred in other Australian species when they were first brought into captivity (Kuchling & Bradshaw 1993). Short term monitoring by Flakus (2002) showed that hatchlings that were incubated artificially survived when released into suitable habitat in the wild.
Protecting nests from predators and trampling
Flat plastic screens, lightly covered with loose sand have been placed over recently constructed nests of the Mary River Tortoise on the main nesting banks between Miva and Tiaro since 2001. In 2002, 52 nests were protected, including most of the nests (probably more than 90%) at the main nesting sandbanks near Tiaro. Electric fencing at some sites prevented cattle trampling and made it easier to find and protect nests (Van Kampen et al. 2003).
Devices to move aquatic animals upstream of dam walls and weirs (fishways)
The design of fishways depends on the height of the wall. Vertical-slot fishways are used for medium-sized weirs and barrages up to 6 m high. They consist of a concrete channel extending from the top of the weir (headwater) to the base of the weir (tailwater). Concrete walls or baffles are then inserted along the length of the channel to slow the flow of water. Vertical-slot fishways usually have a low slope (1:20 gradient) with slow water velocities (1 metre per second) and low turbulence (Larinier et al. 2002; QDPI 2004). There is currently a 200 mm wide vertical slot fishway at the Tinana Creek Barrage, on a tributary of the Mary River (Berghuis et al. 2000). Fishlocks are computerised devices to transfer aquatic species (mainly fish) over dam walls which are usually 8 to 10 m tall. The fishlock consists of a downstream channel at the tailwater (base of the weir) connected to a vertical chamber which extends to the top of the weir. There is an exit chamber at the top of the vertical chamber. Aquatic animals searching for a route upstream seek areas of high flow. Water is discharged from the fishlock to attract them into the downstream channel, and then into a cage at the bottom of the vertical chamber. The gate shuts behind them, the vertical chamber is filled with water, and the cage floats to the top, where another attraction flow entices them to swim into the exit chamber (Larinier et al. 2002; QDPI 2004). Dam walls over 10 m are too high for conventional fishways. A computerised mechanical fish lift similar to a large bucket is being trialled on the Burnett River (ABC, Wide Bay-Burnett 2006).
Few turtles have been seen in fishways, and it is not known to what extent the Mary River Tortoise might use them. Tucker et al. (1999) suggested that radio-tracking studies are needed to determine whether they do. Limpus (as cited in Tucker et al. 1999) stated that river turtles in general seldom walk around stream barriers. The Mary River Tortoise is particularly unlikely to walk far over dry land to get past a dam wall, because it is a strongly aquatic species. Flakus (2002) never found radio-tracked individuals on land, except for the brief nocturnal forays of nesting females onto sand banks a few metres from the shore. Many weirs and dams in the Mary River do not have a fishway (Tucker et al. 1999). Those that do may have insufficient flows to attract aquatic animals, and have inappropriate designs for turtles (Berghuis & Broadfoot 2004a, Tucker et al. 1999). Tucker et al. 1999 suggested that moistened, covered passageways allowing turtles to walk around dam walls may be appropriate for some species. Current fishways are largely designed for upstream movements, although safe downstream passage is equally important for turtles dispersing as juveniles, or migrating to nesting areas (Berghuis & Broadfoot 2004b).
Translocations to alternative or artificial habitat
According to Tucker et al. 1999, relocating turtles may be problematic because species of turtles have generally survived poorly when forcibly moved to a new site. Turtles usually show strong site fidelity and will return, or attempt to return to their original home range. However, studies are needed to test the effect of translocation on the Mary River Tortoise.
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|
|Agriculture and Aquaculture:Agriculture and Aquaculture:Fertiliser application||Movements and home range of Elusor macrurus. Tucker, A.D., ed. Cumulative Effects of Dams and Weirs on Freshwater Turtles: Fitzroy, Kolan, Burnett and Mary Catchments. Page(s) 67-77. (Flakus, S. & M. Wright, 2000) [Report].|
|Agriculture and Aquaculture:Agriculture and Aquaculture:Land clearing, habitat fragmentation and/or habitat degradation||
Movements and home range of Elusor macrurus. Tucker, A.D., ed. Cumulative Effects of Dams and Weirs on Freshwater Turtles: Fitzroy, Kolan, Burnett and Mary Catchments. Page(s) 67-77. (Flakus, S. & M. Wright, 2000) [Report].
Commonwealth Conservation Advice on Elusor macrurus (Mary River Turtle) (Threatened Species Scientific Committee, 2008ac) [Conservation Advice].
|Agriculture and Aquaculture:Livestock Farming and Grazing:Grazing pressures and associated habitat changes||Movements and home range of Elusor macrurus. Tucker, A.D., ed. Cumulative Effects of Dams and Weirs on Freshwater Turtles: Fitzroy, Kolan, Burnett and Mary Catchments. Page(s) 67-77. (Flakus, S. & M. Wright, 2000) [Report].|
|Agriculture and Aquaculture:Livestock Farming and Grazing:Habitat alteration (vegetation, soil, hydrology) due to trampling and grazing by livestock||Commonwealth Conservation Advice on Elusor macrurus (Mary River Turtle) (Threatened Species Scientific Committee, 2008ac) [Conservation Advice].|
|Biological Resource Use:Gathering Terrestrial Plants:Commercial harvest||Population structure and function of turtles of southeast Queensland. Tucker, A.D., ed. Cumulative Effects of Dams and Weirs on Freshwater Turtles: Fitzroy, Kolan, Burnett and Mary Catchments. Page(s) 28-46. (Tucker, A.D., 2000) [Report].|
|Climate Change and Severe Weather:Habitat Shifting and Alteration:Habitat loss, modification and/or degradation||Commonwealth Conservation Advice on Elusor macrurus (Mary River Turtle) (Threatened Species Scientific Committee, 2008ac) [Conservation Advice].|
|Climate Change and Severe Weather:Habitat Shifting and Alteration:Habitat modification with associated erosion||Movements and home range of Elusor macrurus. Tucker, A.D., ed. Cumulative Effects of Dams and Weirs on Freshwater Turtles: Fitzroy, Kolan, Burnett and Mary Catchments. Page(s) 67-77. (Flakus, S. & M. Wright, 2000) [Report].|
|Energy Production and Mining:Mining and Quarrying:Habitat destruction, disturbance and/or modification due to mining activities|
|Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or habitat degradation by weeds||Commonwealth Conservation Advice on Elusor macrurus (Mary River Turtle) (Threatened Species Scientific Committee, 2008ac) [Conservation Advice].|
|Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Competition and/or predation||Vulpes vulpes (Red Fox, Fox)||Population structure and function of turtles of southeast Queensland. Tucker, A.D., ed. Cumulative Effects of Dams and Weirs on Freshwater Turtles: Fitzroy, Kolan, Burnett and Mary Catchments. Page(s) 28-46. (Tucker, A.D., 2000) [Report].|
|Invasive and Other Problematic Species and Genes:Invasive and Other Problematic Species and Genes:Predation, competition, habitat degradation and/or spread of pathogens by introduced species|
|Invasive and Other Problematic Species and Genes:Problematic Native Species:Competition, grazing, predation and/or habitat degradation by rats||The Action Plan for Australian Reptiles (Cogger, H.G., E.E. Cameron, R.A. Sadlier & P. Eggler, 1993) [Cwlth Action Plan].|
|Invasive and Other Problematic Species and Genes:Problematic Native Species:Predation by reptiles||Population structure and function of turtles of southeast Queensland. Tucker, A.D., ed. Cumulative Effects of Dams and Weirs on Freshwater Turtles: Fitzroy, Kolan, Burnett and Mary Catchments. Page(s) 28-46. (Tucker, A.D., 2000) [Report].|
|Natural System Modifications:Dams and Water Management/Use:Changes to hydrology including construction of dams/barriers|
|Pollution:Pollution:Deterioration of water and soil quality (contamination and pollution)|
|Species Stresses:Indirect Species Effects:Poor recruitment (regeneration) and declining population numbers|
Australian Museum (2003a). Fact sheets: Mary River Turtle. [Online]. Available from: http://www.amonline.net.au/factsheets/mary_river_turtle.htm.
Australian Museum Business Services (AMBS) (2004c). Draft National Fauna Survey Standards: Reptiles. Report to the Department of Environment and Heritage.
Berghuis, A.P. & C.D. Broadfoot (2004a). Upstream passage of Queensland lungfish at Ned Churchward Weir Fishlock. Queensland Government Department of Primary Industries, Queensland Fisheries Service, Bundaberg. Report for the Department of State Development, March 2004.
Berghuis, A.P. & C.D. Broadfoot (2004b). Downstream passage of fish at Ned Churchward Weir. Queensland Government Department of Primary Industries, Queensland Fisheries Service, Bundaberg. Report for the Department of State Development, March 2004.
Berghuis, A.P., C.D. Broadfoot & M.J. Heidenreich (2000). Assessment of the Walla Weir Fishlock, Burnett River. Queensland Government Department of Primary Industries. Report to Sunwater.
Berry, J.F. & R. Shine (1979). Sexual size dimorphism and sexual selection in turtles (Order Testudines). Oecologia. 42:185-191.
Cann, J. (1998). Australian Freshwater Turtles. Singapore: Beaumont Publishing Pty Ltd.
Cann, J. & J. Legler (1994). The Mary River Tortoise: a new genus and species of short-necked chelid from Queensland, Australia. Chelonian Conservation and Biology. 1 (2):81-96.
Cogger, H.G. (2000). Reptiles and Amphibians of Australia - 6th edition. Sydney, NSW: Reed New Holland.
Cogger, H.G., E.E. Cameron, R.A. Sadlier & P. Eggler (1993). The Action Plan for Australian Reptiles. [Online]. Canberra, ACT: Australian Nature Conservation Agency. Available from: http://www.environment.gov.au/biodiversity/threatened/action/reptiles/index.html.
Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC) (2011m). Survey guidelines for Australia's threatened reptiles. EPBC Act survey guidelines 6.6 . [Online]. Canberra, ACT: DSEWPaC. Available from: http://www.environment.gov.au/epbc/publications/threatened-reptiles.html.
Duivenvoorden, L.J. (1998). Aquatic Flora of the Burnett River in relation to the Walla Weir- Post Construction Phase:. Page(s) 1998. Report for Queensland Department of Natural Resources, Resource Development and Planning: Brisbane.
Environmental Protection Agency, Queensland (2001). Mary River- water quality condition and trends. Queensland Waterways 6: December 2001.
Flakus, S. (2000). Ontogenetic dietary shifts in an Australian chelid turtle, Elusor macrurus. Tucker, A.D., ed. Cumulative Effects of Dams and Weirs on Freshwater Turtle Populations: Fitzroy, Burnett and Mary River Catchments. Queensland Parks and Wildlife Service. Unpublished report to the Queensland Department of Natural Resources.
Flakus, S. (2002). Ecology of the Mary River Turtle, Elusor macrurus. M.Sc. Thesis. University of Queensland.
Flakus, S. (2003). Personal Communication.
Flakus, S. & M. Wright (2000). Movements and home range of Elusor macrurus. Tucker, A.D., ed. Cumulative Effects of Dams and Weirs on Freshwater Turtles: Fitzroy, Kolan, Burnett and Mary Catchments. Page(s) 67-77. Qld Parks & Wildlife Service, Bundaberg.
Frazer, N.B. (1992). Sea turtle conservation and halfway technology. Conservation Biology. 6:179.
Georges, A. (1995). Mary River Turtle. Nature Australia:. Summer:22.
Georges, A. & S. McInnes (1998). Temperature fails to influence hatchling sex in another Genus and species of chelid turtle, Elusor macrurus. Journal of Herpetology. 32 (4):596-598.
Georges, A. & S. Thomson (2006). Evolution and Zoogeography of the Australian Freshwater Turtles. In: Merrick, J.R., M. Archer., G. Hickey & M. Lee, eds. Evolution and Zoogeography of Australasian Vertebrates. In press. AUSCIPUB (Australian Scientific Publishing) Pty Ltd, Sydney.
Hauser, D. & Members of the Task Force (1992). Our Mary River: a current assessment. Hauser, D. and Members of the Task Force, eds. Our Mary River: a current assessment. Mary River Regional Recreational Study Task Force. Maryborough.
Kind, P.K. (2002). Movement patterns and habitat use in the Queensland lungfish Neoceratodus forsteri (Krefft 1870). Ph.D. Thesis. PhD Thesis, University of Queensland.
Kuchling, G. & S.D. Bradshaw (1993). Ovarian cycle and egg production of the western swamp tortoise Pseudemydura umbrina (Testudines: Chelidae) in the wild and in captivity. Journal of Zoology, London. 229:405-419.
Larinier, M., F. Travade, et al (2002). Fishways: biological basis, design criteria and monitoring.
Latta, C. & G. Latta (2006). Mary River Turtle Elusor macrurus photographic survey performed under Scientific Purposes Permit E4/001080/00/SAA. Unpublished report compiled for the Queensland Museum.
Legler, J.M. & A. Georges (1993). Chelidae. In: Godsell, J., ed. Fauna of Australia, Volume 2: Amphibia, Reptilia, Aves. Page(s) 142-152. Canberra: Australian Biological Resources Study, Dasett.
Limpus, C.J., S. Flakus, D.J. Limpus, A.D. Tucker & T. Priest (1999). Lowered water level impact on freshwater turtles, Wide Bay Creek / Mary River Bridge 1997-1998. Queensland Department of Environment Report.
Micheli-Campbell, M.A., T. Baumgartl, D.T. Booth, H.A. Campbell, M. Connell & C.E. Franklin (2013). Selectivity and Repeated Use of Nesting Sites in a Freshwater Turtle. Herpetologica. 69(4):383-96.
Queensland Department of Primary Industries (2004a). Brisbane. [Online]. Available from: http://www2.dpi.qld.gov.au/fishweb/1932.html.
Thomson, S., M. Hamann, C. Latta & G. Latta (2006). The environmental impacts of dams on the regionally endemic turtles of the Mary River. [Online]. Available from: http://www.travestonswamp.info/_mgxroot/page_10771.html.
Tucker, A.D. (1999). Cumulative Effects of Dams and Weirs on Freshwater Turtles: Fitzroy, Kolan, Burnett and Mary Catchments. Queensland Parks and Wildlife Service. Unpublished report to the Queensland Department of Natural Resources.
Tucker, A.D. (2000). Population structure and function of turtles of southeast Queensland. Tucker, A.D., ed. Cumulative Effects of Dams and Weirs on Freshwater Turtles: Fitzroy, Kolan, Burnett and Mary Catchments. Page(s) 28-46. Qld Parks & Wildlife Service, Bundaberg.
Tucker, A.D. & Priest (1998). Cumulative effects of dams and weirs on freshwater turtles: Jones Weir, Mundubbera. Project report to the Queensland Department of Natural Resources: Brisbane.
Tucker, A.D., T. Priest, E. Guarino & P. Couper (2000). Turtle biodiversity in regard to regional conservation planning: additional recommendations for mitigation in Cumulative Effects of Dams and Weirs on Freshwater Turtles: Fitzroy, Kolan, Burnett and Mary Catchments. Report for Queensland Parks & Wildlife Service, Bundaberg. Page(s) 105-130.
van Kampen, T., S.P. Emerick & D. Parkes (2003). Increasing the Survivorship of the Mary River Turtle. Greening Australia, Tiaro.
Wide Bay-Burnett, A.B.C. (2006). Ladder helps fish scale new heights. 5 April 2006. Viewed 28th August 2006
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). Elusor macrurus in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Sun, 31 Aug 2014 18:21:28 +1000.