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Mary River Turtle (Elusor macrurus)

The Mary River turtle, Elusor macrurus, is a large freshwater turtle found only in the Mary River catchment in south-east Queensland. It uses permanent flowing streams, deep pools, shallow riffles and traditional sandy nesting banks, so clearing, crossings, bank works, water infrastructure and changes to flow or water quality can affect it on development sites.

Conservation status

Commonwealth, EPBC Act 1999: Critically endangered.

Queensland, Nature Conservation Act 1992: Critically endangered.

Breeding season

Mary River turtles mate and nest mainly from October to December on traditional sandy banks beside the Mary River. Eggs remain in nests into summer, with hatchlings emerging from late November to February, so avoid clearing nesting banks and nearby aquatic habitat during this period. The species remains in permanent streams and large pools throughout the year.

Reproductive mode: Egg laying, or oviparous reproduction.

Clutch size: Average 14.7 eggs per clutch. Other reported values are 10 to 25 eggs.

Incubation: About 56 days. Other sources report 50 to 79 days, or up to 75 days depending on conditions.

Size at hatching or birth: Not recorded.

Age at maturity: Approximately 15 to 20 years in the Mary River catchment report. Other sources report females at about 25 years and males at about 30 years.

Nest or egg sites: Traditional, sandy or loamy nesting banks beside the Mary River, usually within 6 m of the water in alluvial deposits. Preferred banks are open, sloping and largely free of vegetation.

Breeding frequency: Most adult females lay one clutch per year and commonly breed in successive years.

Confirm timing locally before works by checking recent nesting records, rainfall and river conditions, because rainfall can trigger nesting and flooding can drown or remove nests.

  • Mating: Mating is reported during October to December. Specific mating behaviour and the timing within that period are not documented.
  • Gravid females: Females carrying oviducal eggs are recorded during the nesting period, October to December. The documents do not define the full duration of pregnancy or egg retention for this species.
  • Nesting: Nesting occurs from October to December, including late October to December at the Tiaro nesting banks. Females generally nest at night after rainfall and lay one clutch per year.
  • Incubation: Eggs laid from October to December can remain in nests into summer. Incubation is reported as about 56 days, with other sources giving 50 to 79 days or up to 75 days, so the likely calendar period is October to February.
  • Hatchlings: Hatchlings emerge from late November through summer. The supplied sources give emergence or hatching as late November to early January, December to February, or generally during summer.
  • Active period: No species-specific inactive season is documented. Mary River turtles use permanent streams and large pools throughout the year, with adults moving to nesting banks during October to December.
  • Highest clearing risk: The highest risk is from October to February, when adults nest, eggs are in banks and hatchlings emerge. October to December is the peak risk period because nesting is concentrated then; aquatic habitat remains occupied and at risk in every month.

Identification

The Mary River turtle is a large, streamlined freshwater turtle with a low shell and a moderately short neck. It is most often detected in clear permanent streams by snorkelling, from basking observations, or through records of nesting activity on sandy river banks.

Adults have a low, streamlined shell, moderately short neck, and well-webbed fore and hind limbs. Adult males have an exceptionally long tail, reaching about 70 percent of shell length, and are larger than females. Adult males are among the largest freshwater turtles in Australia.

Adult shell length: About 34 cm

Hatchling shell length: 3 to 4 cm

Distinctive male feature: Very long tail, up to about 70 percent of shell length

Identification: Distinguishing features

The species has a distinctive horny casque on the top of the head and large barbells or rounded tubercles under the chin. Krefft's river turtle, Emydura macquarii krefftii, generally has a smooth head and smaller chin barbells. The saw-shelled turtle, Wollumbinia latisternum, has serrations along the rear edge of the carapace, which are absent in adult Mary River turtles. The Victoria River snapping turtle has short, blunt neck tubercles rather than the longer, sharper tubercles of the Mary River turtle.

Identification: Field signs and detection

Females gather at traditional sandy nesting banks, where tracks and nest excavations may be visible in spring and early summer. Basking animals may be seen on emergent logs, rocks or banks, especially in the morning and afternoon. During floods, turtles use backwaters and eddies, then return towards their former positions as flow intensity decreases.

  • Treat turtle tracks, nest chambers, egg shells and disturbed sand on river banks as potential evidence of breeding activity.
  • Use good quality colour photographs for records that may be Mary River turtles, and submit photo vouchers to the relevant Queensland fauna authority and Queensland Museum.
  • In clear water, snorkelling is the preferred detection method. Baited traps, seine netting and distant binocular observations of basking turtles can also be used by appropriately authorised personnel.
  • Larger traps may be needed for this species. Traps must remain partly above water and be checked frequently enough to prevent drowning.

Distribution: National range

The Mary River turtle is endemic to one river system in Queensland. No other Australian state or catchment forms part of its known natural range.

The species occurs only in the Mary River catchment in south-east Queensland. It is recorded in the main Mary River and major tributaries, including Tinana Creek, Yabba Creek and Obi Obi Creek. Records extend from the downstream freshwater limit near the Mary River Barrage upstream to mountain streams above Kenilworth.

  • Queensland: Mary River catchment, including the Mary River, Tinana Creek, Yabba Creek and Obi Obi Creek.
  • No records are given for New South Wales, Victoria, South Australia, Western Australia, the Northern Territory, Tasmania or the Australian Capital Territory.
  • The species has not been recorded from temporary wetlands, farm dams or other artificial water bodies in otherwise ephemeral stream areas.

Distribution: Strongholds and subpopulations

Important nesting aggregations occur near Tiaro in the lower catchment. Lower-density nesting banks occur upstream between Traveston and Kenilworth. The turtle has also been recorded in the Mary River Barrage impoundment, Tallegalla Weir on Tinana Creek and Imbil Weir on Yabba Creek. It has been recorded downstream of Borumba Dam but not within the Borumba Dam impoundment or further upstream in Yabba Creek.

Distribution: Population status

Historical egg collection for the pet trade occurred from the 1960s until 1974. The main Tiaro nesting population was estimated to have declined by about 95 percent between the 1960s and the late 1990s. Populations in many sampled areas were dominated by ageing adults, with few immature turtles. More recent work found recruitment in the upper catchment but very low recruitment in the lower catchment.

Historical decline at main Tiaro nesting banks: Approximately 95 percent from the 1960s to the late 1990s

Egg collection period: 1960s to 1974

Nest protection programme: 631 nests protected and an estimated 9,465 hatchlings entering the lower catchment since the programme began

Current population size: No reliable whole-population estimate is provided in the supplied documents

Habitat: Aquatic habitat

This species depends on permanent freshwater habitats rather than isolated temporary wetlands. Habitat quality is closely linked to flow, dissolved oxygen, water clarity, river structure and access to sandy nesting banks.

Adults use deep pools in moderately broad mid-reaches of rivers, shallow flowing water and highly oxygenated riffles. The species occurs mainly in the main river and major permanent tributaries, including large pools and mountain stream habitats. Small juveniles have the greatest need for water with adequate dissolved oxygen because they use cloacal ventilation.

  • Retain permanent pools, flowing reaches, shallow riffles, backwaters and eddies.
  • Protect rocky riffles and shallow fast-flowing areas from infilling, scour, dewatering and conversion to slow, deep impounded water.
  • Maintain water quality and dissolved oxygen, especially in shallow juvenile habitat.
  • Avoid isolating pools or severing stream connectivity during works and water extraction.

Habitat: Riparian and bank features

Riparian vegetation helps stabilise river banks and sand islands. Large log tangles, submerged wood, emergent logs and bank cover provide habitat for basking, refuge and movement. Traditional nesting banks are substantial sandy banks, which are uncommon along the river and are not interchangeable with every apparently suitable sand bank.

  • Retain riparian vegetation, stable sandy nesting banks, large woody debris and submerged structural cover.
  • Do not assume that an apparently suitable sand bank is a nesting site. Confirm use through targeted surveys before bank disturbance.
  • Avoid sedimentation, bank compaction, stock access and direct disturbance at known nesting banks.

Habitat: Climate and elevation

The supplied documents describe a catchment extending from the Mary River mouth and lower freshwater reaches through the hinterland to mountain streams above Kenilworth. They do not provide a species-specific elevation limit. The species is associated with permanent streams and large pools in the subtropical Mary catchment.

Foraging habitat: Diet and feeding sites

Mary River turtles feed within the river, with adults associated particularly with rocky riffles. The available studies identify animal prey and do not provide a complete list of all foods used by the species.

Adults feed on bivalves, gastropods and aquatic insects that are available in rocky riffles. Juveniles use shallow backwaters above fast-flowing shallow riffles, probably to access food while reducing the distance travelled between the river bed and the surface.

Recorded adult prey: Bivalves, gastropods and aquatic insects

Adult foraging habitat: Rocky riffles

Juvenile foraging habitat: Shallow backwaters above fast-flowing shallow riffles

  • Retain rocky riffles, shallow backwaters and the connection between these habitats.
  • Avoid works that remove riffle substrates, increase siltation, reduce dissolved oxygen or convert flowing habitat into deep slow water.
  • Manage lighting, noise, vibration and in-stream activity to minimise disturbance during aquatic surveys and construction.

Foraging habitat: Foraging movements

The supplied documents do not provide a complete home-range estimate. During the breeding season, females may move up to 2 kilometres between their foraging area and a nesting sand bank. Male movements are generally less extensive than female movements.

  • Survey and assess both the waterway and nearby banks within at least the documented 2 kilometre breeding movement distance where nesting banks are present.
  • Keep movement corridors between foraging habitat and nesting banks open during construction and operation.

Breeding habitat: Breeding biology

Breeding depends on access to traditional sandy nesting banks beside permanent streams. Most adult females breed each year, but recruitment remains low because eggs and hatchlings are exposed to high mortality.

Females aggregate at traditional nesting banks and generally lay one clutch per year. Eggs are laid in spring and early summer and hatchlings emerge in summer, usually from late November to early January. The supplied documents do not state a reliable clutch-size range, incubation period, gestation period or lifespan for this species.

Breeding and laying season: Spring to early summer

Hatching season: Summer, late November to early January

Clutch frequency: Most adult females lay one clutch per year

Age at first breeding: Approximately 15 to 20 years

Clutch size: Not stated in the supplied documents

Incubation period: Not stated in the supplied documents

Lifespan: Not stated in the supplied documents

  • Treat nesting banks as active breeding habitat from spring through early summer, with potential hatchling emergence through late November and early January.
  • Avoid clearing, excavation, vehicle access, stock access, lighting and vibration on or near known nesting banks during the nesting and hatching period.
  • Use nest protection or predator management only under an approved species management programme.

Breeding habitat: Nesting habitat

The main nesting aggregation is near Tiaro, with additional lower-density nesting banks between Traveston and Kenilworth. Substantial sand banks are uncommon, and many sand banks that appear suitable are not used at significant levels. Nesting banks can be affected by flooding, predation and trampling.

  • Map known nesting banks and inspect suitable sandy banks for tracks, nest chambers and recent disturbance before works.
  • Maintain bank stability and avoid changing flow patterns that could inundate nests or remove nesting substrate.
  • Prevent cattle, dogs, foxes and pigs from accessing protected nest areas where authorised management measures are in place.

Sheltering habitat: Aquatic refuges

The species shelters in aquatic habitats and uses physical structure within and beside the stream. The supplied documents do not identify dens, burrows, tree hollows or a defined shelter size.

Turtles use deep pools, large permanent pools, shallow backwaters and eddies. During flood events they position themselves in backwaters and eddies, returning towards former positions as flow intensity decreases. Juveniles use shallow backwaters above riffles.

  • Retain deep pools, backwaters, eddies, riffle margins, submerged logs and log tangles.
  • Do not dewater pools or isolate refuge habitat during construction, maintenance or water extraction.
  • Provide a fauna management response for turtles found in work areas. Capture, handling and relocation must be undertaken by suitably authorised personnel.

Sheltering habitat: Basking and bank cover

Mary River turtles bask at the water surface and on dead wood, rocks and banks. Emergent logs and submerged trees are recognised survey locations and provide structure within the stream.

  • Retain emergent and partially submerged logs where they do not create an unavoidable safety hazard.
  • Inspect basking structures and quiet backwaters before vegetation removal, piling, dredging or bank stabilisation.
  • Do not remove woody debris from the channel without assessing its value as turtle habitat.

Sheltering habitat: Infrastructure refuges and hazards

Dams, weirs, release structures and trash screens can concentrate turtles and cause injury or death. Structures can also block upstream and downstream movement. No existing fishway has been demonstrated to provide safe passage for turtles in the Mary catchment material supplied.

  • Inspect water intakes, trash screens, weir pools, plunge pools and release points for turtles before and during works.
  • Use turtle-sensitive design and seek advice from turtle biologists and engineers for new or modified water infrastructure.
  • Maintain safe passage and avoid trapping turtles against screens, walls or high-velocity outlets.

Threats: Clearing and development

The main risks are loss of eggs and recruitment, altered river habitat and flow, poor water quality, infrastructure injury, predation and disturbance of nesting banks. The species has a restricted range and delayed maturity, so local losses may take many years to become evident.

Clearing riparian vegetation, removing large woody debris, disturbing river banks and damaging sandy nesting banks can remove habitat or reduce breeding success. Roads, fencing and other land-use changes can impede turtle movement. Development in or beside the Mary catchment has also contributed to bank, wetland and waterway modification.

  • Avoid clearing permanent stream banks, riparian vegetation, nesting banks, emergent logs and riffle margins.
  • Keep fencing away from movement routes and design unavoidable fences to reduce trapping and collision risk.
  • Use pre-clearance aquatic and nesting-bank surveys for projects within the Mary River catchment.

Threats: Hydrology and water quality

Dams, weirs and water extraction can reduce connectivity, alter flow, inundate nests, convert shallow riffles to deep slow water and reduce access to suitable habitat. Juveniles are particularly sensitive to reduced dissolved oxygen. Pollution, siltation and infilling of pools can further reduce habitat quality.

  • Maintain environmental flows that support movement during breeding and nesting periods without inundating active nests.
  • Prevent sediment, pollutants and low-oxygen water from entering occupied reaches.
  • Assess cumulative effects of multiple impoundments, crossings, offtakes and temporary pool isolation.

Threats: Predation, trampling and recruitment failure

Egg predation by foxes, dogs, pigs, goannas and water rats is a major cause of recruitment failure. Feral pigs can also uproot aquatic plants and increase turbidity, anoxia and eutrophication. Cattle trampling has been associated with turtle fractures and can damage nesting banks.

  • Control access by dogs, pigs and stock to known nesting banks where this forms part of an approved management programme.
  • Do not rely on nest protection alone. Monitor hatchling survival and juvenile recruitment in the river.
  • Keep domestic animals and construction camps away from nesting banks and known turtle habitat.

Threats: Fire, roads and disease

The supplied documents do not identify fire as a primary direct threat to Mary River turtles. They do identify roads, fencing and infrastructure as movement and mortality risks. No species-specific disease threat is described in the supplied documents.

  • Assess fire-related sediment runoff, bank instability and loss of riparian cover where fire or planned burning occurs near occupied streams.
  • Install and maintain fauna-sensitive crossing controls where roads or temporary access tracks cross streams or turtle movement routes.
  • Report sick, injured or dead turtles through the relevant Queensland fauna authority and follow approved hygiene procedures between water bodies.

Survey methodology: 1. Aquatic visual searches

Survey the Mary River turtle in permanent streams, deep pools, riffles and associated nesting sandbanks within the Mary River catchment. Surveys should be led by suitably experienced freshwater turtle personnel and use methods that minimise handling, drowning and disturbance.

Diving in clear water is the most effective capture method for this species, although it is time consuming and depends on water clarity.

Search deep pools, moderately broad river reaches, highly oxygenated riffles, overhanging banks and fallen submerged trees.

Undertake surveys during the warmer months, from late spring through summer, when activity is higher.

Use morning and afternoon searches to detect turtles basking at the water surface, on emergent logs or on banks, and record observations with binoculars where possible.

Record the search area, water clarity, flow, weather, start and finish times, observers, effort and all turtle observations.

Survey methodology: 2. Baited aquatic traps

Use specially built traps for this large turtle where diving is unsuitable, and place them along banks among overhangs and fallen submerged trees.

Suspend traps so that the top 3 to 5 centimetres remain above the water, or secure them to floats, so captured turtles can breathe.

Use fresh meat or drained sardines in a mesh bait bag, and check traps several times during the first hour or two after setting, then several times during the day, several hours after sunset and again early the next morning.

Remove traps if they cannot be checked at the required frequency or if turtle numbers could cause the traps to sink and drown animals.

Record trap locations, bait, deployment and retrieval times, trap nights, checks, captures, bycatch and any injuries.

Trap clearance above water: 3 to 5 centimetres

Survey methodology: 3. Seine netting

Use seine nets in shallow areas, including water up to 3 metres deep, where the bed has relatively few snags and other obstacles.

Use this method particularly where water is turbid and diving visibility is poor.

Obtain any required fishing or wildlife authorisations before using nets, and use enough personnel to prevent turtles being held underwater or damaged against snags.

Record the net length, swept area, number of hauls, depth, duration, conditions, captures and bycatch.

Reported suitable depth: Up to 3 metres

Survey methodology: 4. Nesting bank and basking searches

Inspect traditional and potential sandbanks during the breeding period in spring and early summer, taking care not to trample tracks, nests or loose sand.

Search a female's likely movement area around nesting banks, noting that available data indicate movements of up to 2 kilometres during the breeding season.

Observe basking turtles from a distance with binoculars during morning and afternoon periods rather than approaching or repeatedly flushing them.

Map tracks, nesting attempts, active nests, bank condition, access routes and evidence of fox, dog, pig, goanna or water rat activity.

Recorded breeding movement distance: Up to 2 kilometres from the foraging area to a nesting sandbank

Egg laying period: Spring and early summer

Survey methodology: 5. Minimum effort and reporting

  • Prepare a project specific survey design that covers all permanent streams, large pools, riffles, submerged timber, overhanging banks and nesting sandbanks within or downstream of the disturbance area.
  • State the proposed survey method, dates, times, weather, flow, water clarity, water depth, observer qualifications, search area, trap nights or netting effort and detection limitations.
  • Treat a failure to detect turtles as inconclusive where water is turbid, access is restricted, flow is high, suitable habitat was not sampled or effort was not adequate for the habitat present.
  • Use photographs and precise coordinates for records, and have potential records confirmed by an experienced turtle specialist where identification is uncertain.
  • Submit confirmed records, negative survey results and relevant habitat records to the relevant Queensland wildlife database and provide records to the project approval authority where required.
  • Retain field sheets, photographs, track logs, trap check records, animal welfare records and any permits with the project environmental records.

Before habitat disturbance: Avoid and minimise

Avoid direct disturbance to permanent stream habitat, shallow highly oxygenated water, deep pools, nesting sandbanks and movement routes. Plan the works around the species' restricted distribution and its dependence on flowing water, suitable dissolved oxygen and successful recruitment.

  • Retain permanent streams, deep pools, riffles, shallow flowing water, submerged logs, overhanging banks, riparian vegetation and traditional or active nesting sandbanks.
  • Keep machinery, stockpiles, access tracks, refuelling areas and sediment controls out of the stream, nesting banks and retained turtle habitat wherever practicable.
  • Maintain movement between aquatic habitat, foraging areas and nesting banks, noting that females may move up to 2 kilometres to nest.
  • Avoid changes to flow, water level, dissolved oxygen, turbidity and sediment delivery that could affect juveniles, which have a high requirement for well oxygenated water.
  • Do not remove or reshape a sandbank, deepen a pool, fill a backwater or clear submerged timber without site specific ecological assessment and approval.

Before habitat disturbance: Approvals and work planning

  • Check whether the action requires referral or approval under the EPBC Act and obtain all Queensland wildlife, animal ethics, fisheries, waterway and local approvals before works start.
  • Prepare a fauna management plan that identifies turtle habitat, nesting banks, aquatic survey results, exclusion zones, stop-work triggers, authorised handlers, release sites, incident procedures and reporting requirements.
  • Schedule ground and aquatic disturbance outside the spring and early summer nesting period where practicable.
  • Stage works so that retained flowing water and escape routes remain available, and complete high-risk activities in short, supervised work areas.
  • Consult a freshwater turtle specialist before works affecting dams, weirs, culverts, stream crossings, water releases or any permanent Mary River habitat.

Before habitat disturbance: Site preparation

  • Complete a pre-clearance aquatic and nesting bank inspection immediately before disturbance, because turtle presence can vary with flow, water clarity and season.
  • Mark no-go areas around streams, deep pools, riffles, nesting banks, submerged timber and riparian vegetation before machinery enters the site.
  • Install exclusion fencing only where it will not block turtle movement to water or nesting habitat, and inspect it daily for trapped or displaced turtles.
  • Use sediment, erosion, spill and dewatering controls that prevent turbid or oxygen-poor water entering retained habitat.
  • Plan any dewatering with a qualified aquatic fauna practitioner, including a staged search, capture, holding, release and contingency procedure.

During habitat disturbance: Daily controls and machinery interface

Keep a qualified fauna spotter catcher and the machine operator in direct communication throughout works near water or nesting habitat. Stop work when controls fail or a turtle, nest or suitable habitat feature is at risk.

  • Hold a daily pre-start briefing covering exclusion zones, access routes, turtle habitat, weather, water conditions, stop-work triggers and the location of the authorised fauna handler.
  • Inspect fencing, sediment controls, ramps, trenches, stockpiles and water diversion structures before work starts and after heavy rain or flow changes.
  • Use a spotter to inspect the work area immediately before machinery moves, while the operator works at reduced speed and stops on the spotter's instruction.
  • Keep machinery out of the water unless the approved method specifically requires entry, and prevent buckets, wheels and tracks from contacting turtles, nests, logs or sandbanks.
  • Do not allow workers to chase, corner, repeatedly flush, feed, collect or handle turtles unless they are authorised and trained for the task.

During habitat disturbance: Habitat features and aquatic works

  • Treat sandbanks, turtle tracks, nests, shallow riffles, deep pools, backwaters, submerged logs and overhanging banks as protected habitat features during the work.
  • Do not move logs, rocks or bank material into water or onto nesting sandbanks without ecological approval and a documented relocation method.
  • Before dewatering or isolating a channel, complete a turtle search using the approved combination of diving, traps, seine netting and visual observation.
  • Maintain water depth, flow and oxygen conditions in retained habitat, and prevent dirty, stagnant or chemically contaminated water from entering the stream.
  • Keep excavated material, concrete washout, fuels, oils and other contaminants away from water and nesting banks.

During habitat disturbance: If a turtle is found

  • Stop the activity that could affect the turtle and establish a safe exclusion area until the authorised fauna handler assesses the animal and habitat.
  • Allow a healthy turtle to move away unaided where it is safe to do so, and do not pick it up for convenience or move it unnecessarily.
  • If capture is required, use only the handling method approved in the fauna management plan and limit handling, restraint, transport time and exposure to heat.
  • Release a healthy turtle into nearby retained habitat that matches the capture habitat and is outside the work zone, unless the relevant wildlife authority or turtle specialist directs another action.
  • Do not release a turtle into a farm dam, temporary wetland or unfamiliar waterbody, because the species is associated with permanent streams and large pools in the Mary catchment.
  • Place injured, weak or contaminated turtles in a secure, ventilated container and arrange prompt assessment by a veterinarian, licensed wildlife carer or appropriately authorised wildlife officer.
  • Record the species, identification features, sex or life stage if known, condition, location, time, action taken, release location, photographs, handler and any permit or incident number.

During habitat disturbance: Stop-work triggers and records

  • Stop work if a turtle, active nest, nesting bank or unapproved habitat disturbance is found within the work area.
  • Stop work if exclusion fencing traps an animal, sediment enters retained water, a spill occurs, dewatering controls fail or machinery cannot maintain the approved separation from habitat.
  • Stop work if water becomes visibly turbid, stagnant, contaminated or substantially altered in flow or level and the fauna management plan does not cover the condition.
  • Notify the site environmental officer, fauna specialist and approval authority as required, and do not resume until the risk is assessed and controls are restored.
  • Maintain daily records of inspections, turtle sightings, captures, relocations, injuries, mortalities, environmental incidents, weather, rainfall, water conditions, works completed and corrective actions.

After habitat disturbance: Post-clearance checks

Confirm that the work area is safe, that no turtles or nests remain at risk and that aquatic and nesting habitat controls remain effective. Report outcomes and retain records required by approvals.

  • Complete a final inspection of the work area, access routes, trenches, drains, fencing, stockpiles, water diversion structures and retained stream habitat before demobilisation.
  • Search areas where visibility was reduced by machinery, vegetation, turbidity, dewatering or temporary barriers, and remove hazards that could trap turtles.
  • Inspect nesting banks for damaged tracks, exposed nests, compaction, sediment deposition and altered access, and refer any nest or bank damage to the fauna specialist.
  • Confirm that all captured animals were accounted for and that release locations, condition and follow-up requirements are documented.

After habitat disturbance: Monitoring and maintenance

  • Maintain exclusion fencing, sediment controls, spill controls, water quality controls and safe crossing arrangements until the site is stable and rehabilitation is established.
  • Monitor retained streams, pools, riffles and nesting banks after rainfall, flow changes and major construction stages.
  • Use repeat aquatic and basking surveys where the project altered flow, water quality, bank form, riparian cover or access to nesting habitat.
  • Investigate any turtle injury, mortality, loss of recruitment, nest loss or unexpected change in habitat condition and apply corrective action.

After habitat disturbance: Reporting and offsets

  • Submit the required completion report, fauna incident reports, turtle records, photographs, coordinates and monitoring results to the approval authority and relevant Queensland wildlife database.
  • Report any non-compliance, injury, mortality, unauthorised habitat damage or failure of a fauna management measure under the project's approval conditions.
  • Implement approved offsets or other compensatory measures where residual impacts remain after avoidance and mitigation.
  • Link offset and monitoring actions to measurable outcomes for permanent flowing water, dissolved oxygen, nesting banks, juvenile habitat and recruitment.

Rehabilitation actions: Restore aquatic and nesting habitat

Rehabilitation should restore the permanent stream functions and nesting resources used by the Mary River turtle. Prioritise water quality, flow, stable banks, suitable sandbanks, riparian cover and predator management over cosmetic site treatment.

  • Reinstate natural or approved stream flow paths, deep pools, shallow riffles, backwaters and well oxygenated water where these features were disturbed.
  • Stabilise banks without sealing or overengineering nesting sandbanks, and retain or recreate sandy, accessible banks where the approved design identifies nesting potential.
  • Replant locally appropriate native riparian vegetation to reduce erosion, shade water, provide cover and contribute fruits and woody habitat to the stream.
  • Retain or reinstate submerged logs and suitable bank cover where they do not obstruct flow, navigation, approved infrastructure or turtle movement.
  • Design culverts, crossings, weirs and other structures to preserve aquatic connectivity and reduce turtle injury, trapping and mortality.

Rehabilitation actions: Predator, weed and fire management

  • Control weeds and maintain riparian plantings so that dense native cover establishes without covering or destabilising known nesting banks.
  • Manage feral dogs, foxes and pigs around nesting banks in accordance with approved pest management and animal welfare requirements.
  • Protect nests from trampling and predators where monitoring shows that nest loss is limiting recruitment, using methods approved by the turtle specialist and relevant authorities.
  • Prevent fire, slashing, grazing and vehicle access from damaging nesting banks, riparian vegetation or newly established habitat.
  • Do not use broadscale chemical treatments where runoff could reduce water quality or harm turtles, prey or aquatic habitat.

Rehabilitation actions: Monitoring and success measures

  • Inspect restored reaches and nesting banks after rainfall, floods, droughts and major flow releases for erosion, sediment deposition, weed invasion and loss of turtle access.
  • Measure survival and cover of plantings, bank stability, persistence of pools and riffles, water clarity and dissolved oxygen where these are project risks.
  • Monitor turtle presence, basking records, aquatic captures, nesting activity, nest predation, juvenile occurrence and injuries using repeat methods that match the baseline survey.
  • Treat successful rehabilitation as sustained habitat function and safe turtle use, not only completion of planting or earthworks.
  • Continue monitoring until approved performance criteria are met, and adapt bank, flow, predator, weed or access management when results show poor recruitment or habitat decline.

Sources