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Northern River Shark (Glyphis garricki)

The Northern River Shark is a rare, medium-sized river shark of northern Australia. It uses turbid rivers, estuaries, tidal embayments and nearby marine waters, so works near waterways can affect habitat or cause accidental capture. It is listed as Endangered under the EPBC Act and in the Northern Territory, and any take in the Northern Territory is illegal.

Conservation status

Commonwealth, EPBC Act 1999: Endangered.

Northern Territory, Territory Parks and Wildlife Conservation Act 1976: Endangered.

Breeding season

The Northern River Shark is poorly known, but births have been recorded in October in northern Australia. Timing may vary between river systems and regions, and there is not enough evidence to define a wider breeding season.

Breeding mode: Placental viviparity. Females give birth to live young.

Litter size: Nine embryos or pups were recorded in one mature female. The wider Glyphis genus is reported to have litters of fewer than five, so species-specific litter size remains uncertain.

Birth timing: Free-swimming young have been recorded in October, suggesting births occur around October.

Gestation: Not recorded.

Breeding sites: Not recorded. No specific pupping habitat or maternity area has been identified.

Age at maturity: Males mature at approximately 142 cm total length. Female age or size at maturity is not established, although a 177 cm female was mature.

Breeding frequency: Not recorded for the Northern River Shark. The Glyphis genus is reported to breed once a year or every 2 years.

Records are sparse, so breeding and risk periods may vary between years and between river systems in Western Australia and the Northern Territory.

  • Pupping and births: One record of free-swimming young in October indicates that pupping may occur at this time.
  • Newborn young present: Newborn or very young sharks have been recorded in October, but the duration of this period is unknown.
  • Juvenile and subadult habitat use: Juveniles and subadults use freshwater, estuarine and marine habitats, with no seasonal pattern established.
  • Adult and wider river, estuarine and marine presence: The species can occur across riverine, estuarine, inshore and marine habitats, but seasonal movement timing is unknown.
  • Highest clearing risk: October has the highest potential risk because births and very young sharks have been recorded then, although no specific pupping area is known.

Identification: Appearance and size

The Northern River Shark is a medium-sized whaler shark with a small eye, blunt snout and triangular dorsal fins. Identification can be difficult, especially where it occurs with the Speartooth Shark or Bull Shark.

The dorsal surface is steely grey or slate grey, with an abruptly white underside. The snout is short, broadly rounded when viewed from above and bluntly pointed when viewed from the side.

The second dorsal fin is about two-thirds the height of the first dorsal fin. The first dorsal fin has a nearly straight rear margin.

Teeth: Upper teeth are broad, triangular and blade-like. Lower teeth are tall, narrow and slender.

Eye: Very small, with the grey to white colour boundary extending well below the eye.

  • Females have reached 251 cm.
  • Males have reached 144 cm.
  • Size at birth is about 55 cm.
  • The species may grow to 2 to 3 m.

Identification: Similar species

The Northern River Shark can be confused with the Bull Shark, particularly in turbid water. Its proportionally larger second dorsal fin and smaller eyes can assist with comparison, but field identification should be treated cautiously.

It is particularly difficult to distinguish from the Speartooth Shark, Glyphis glyphis, where the two species occur together. The Northern River Shark generally has a longer, flatter snout and more grey below the eye. Confirmed identification may require photographs, genetic testing or examination of vertebral and dental characters.

Calls and echolocation: No calls or echolocation behaviour are known for this shark. Acoustic tracking has been used for research, but it is not a field identification method.

  • Do not rely on a single feature when recording a sighting.
  • Photograph the whole animal, head, fins, teeth where safe, and the colour boundary below the eye.
  • Do not handle, restrain or retain a shark for identification.

Identification: Field signs and site records

There are no reliable terrestrial field signs such as droppings, nests, whitewash, stains or odours. A live sighting, capture, carcass, jaw or other shark part should be treated as a significant record.

Record the date, exact location, waterway, tide if known, water clarity, salinity if measured, photographs and the animal's condition. Keep any suspected capture separate from other catch and seek advice from the relevant authority.

Protection: Listed as Endangered under the EPBC Act and in the Northern Territory. Any take is illegal in the Northern Territory.

  • Do not use bait or fishing gear to search for the species during construction works.
  • Do not release a captured animal into a different waterway without direction from the relevant authority.
  • Report any capture, injury or death promptly.

Distribution: Western Australia

The Australian range extends across northern Western Australia and the Northern Territory, but records are sparse and the distribution remains poorly understood. Treat suitable northern rivers, estuaries and adjacent tidal waters as potential habitat during project planning.

Records include the Kimberley coast, King Sound, the Ord River, King River, the West Arm of Cambridge Gulf and Joseph Bonaparte Gulf.

The species is associated with large, macrotidal river and estuarine systems, including turbid lower reaches and connected marine habitats.

Mapped Australian states: Western Australia and the Northern Territory

  • West Kimberley and East Kimberley
  • King Sound
  • Ord River and King River
  • Cambridge Gulf and Joseph Bonaparte Gulf

Distribution: Northern Territory

Known records include the Adelaide, Daly, South Alligator and East Alligator river systems. Records also include the Wessel Islands and marine areas near the Northern Territory coast.

The Alligator River system requires careful identification because both the Northern River Shark and Speartooth Shark occur there.

Conservation areas: The species has been recorded in Kakadu National Park, including the Alligator River system.

  • Adelaide River system
  • Daly River
  • South Alligator River
  • East Alligator River
  • Wessel Islands

Distribution: Overseas range

The species is believed to occur in Australia and southern New Guinea. Outside Australia, records include the Fly River and confirmed coastal records near Daru in Papua New Guinea.

The relationship between Australian and Papua New Guinean populations is not fully resolved.

Record limitations: Sparse records do not demonstrate that a waterway is free of Northern River Sharks.

  • Treat records from northern Australian waterways as nationally significant.
  • Include connected estuarine and marine habitat in the site assessment, even where no shark record is known.

Habitat: River and estuary features

Look for the species in large tropical rivers and estuaries with strong tidal influence, high turbidity and soft muddy beds. Habitat can extend from freshwater reaches through brackish water to the sea.

Potential habitat includes shallow to moderately deep river channels, tidal reaches, muddy banks, estuarine channels and macrotidal embayments. Juveniles and subadults use freshwater, estuarine and marine habitats.

Adults have been recorded in marine environments, including inshore waters and offshore areas. A project should therefore consider the full waterway connection, not only the immediate riverbank.

Recorded salinity: Records range from freshwater to seawater, including about 2 to 36 parts per thousand.

Water clarity: Recorded waters have had Secchi depths of 3 to 70 cm.

  • Large tropical rivers with tidal flow
  • Shallow, brackish upper and middle estuarine reaches
  • Highly turbid lower river channels
  • Macrotidal embayments and connected coastal waters

Habitat: Substrate and water conditions

The species is associated with fine muddy substrate and turbid water. Strong tidal exchange and low-oxygen conditions may be tolerated better than by many other sharks.

During site inspections, map channels, tidal creeks, pools, muddy margins and areas where construction could increase sediment movement or alter salinity.

Vegetation: No particular plant community has been identified as essential habitat. Assess the waterway, banks, floodplain connections and tidal channels together.

  • Fine mud and soft sediment
  • Turbid water with limited visibility
  • Tidal channels and creek junctions
  • Freshwater to brackish transitions

Habitat: Site assessment

For clearing, dredging, piling, bank works, causeways and temporary access, check whether the footprint connects to a large river, estuary or tidal embayment. Include indirect effects such as sediment plumes, altered flows, barriers and changes to salinity.

Where a project is near potentially suitable habitat, obtain advice early from the relevant Commonwealth and state or territory regulators. A desktop assessment alone may not exclude occurrence in a poorly surveyed waterway.

Occurrence: The species is rare and difficult to detect. Absence from a short survey should not be treated as proof of absence.

  • Map upstream and downstream connectivity before works begin.
  • Identify works that could block channels or change tidal exchange.
  • Plan sediment, spill and erosion controls for all in-water and bank works.
  • Use qualified aquatic fauna specialists for any targeted assessment.

Foraging habitat: Prey and feeding areas

The Northern River Shark feeds mainly on fish in turbid river, estuarine and marine habitats. Feeding areas are not defined by a single vegetation type, so protect connected channels and productive muddy-water habitats.

Recorded prey includes bony fish such as salmon, forktailed catfish and barramundi. Mud crabs and stingrays also form part of the diet.

Likely feeding areas include tidal channels, river mouths, muddy banks and other places where fish and crustaceans are concentrated. These areas can be affected by bank disturbance, changed flows and loss of connectivity.

Foraging behaviour: Detailed species-specific feeding locations and behaviour are not established.

  • Turbid river channels
  • Estuarine creek junctions and river mouths
  • Muddy tidal margins
  • Connected inshore and marine waters

Foraging habitat: Construction risks to feeding habitat

Dredging, excavation, pile driving, bank armouring, dewatering and sediment discharge can disturb prey habitat or restrict access between feeding areas.

Fishing activity around a work site can also create a capture risk. Do not use gillnets, longlines or other shark-catching gear as part of project operations.

Fishing interaction: Gillnetting, longlining, recreational fishing and illegal fishing are recognised risks, particularly where mature animals or juveniles are caught.

  • Keep spoil and sediment out of connected channels.
  • Prevent fuel, concrete washout and other pollutants entering the water.
  • Maintain fish passage and tidal exchange wherever practicable.
  • Coordinate any unavoidable in-water works with the relevant authorities.

Foraging habitat: Survey approach

There is no simple visual survey for feeding habitat or presence. If a project could affect suitable waterways, use a risk-based aquatic fauna assessment designed by an experienced elasmobranch ecologist.

Record water depth, salinity, turbidity, tide, channel form, substrate and nearby fish habitat. Do not increase capture risk by adding fishing effort without specific approval.

Detection: The species is solitary, rare and easily confused with other sharks. Detection probability is likely to be low.

  • Use existing records and local fishery knowledge as screening information.
  • Survey connected habitat rather than only the construction footprint.
  • Photograph and report any shark capture or carcass immediately.

Breeding habitat: Reproduction

The Northern River Shark gives birth to live young, but its pupping areas and breeding habitat are poorly understood. Treat shallow, connected freshwater and brackish reaches as sensitive where juveniles could occur.

The species is placentally viviparous. A mature female has been recorded with 9 early-stage embryos, and one female was recorded with 9 pups.

Free-swimming young have been found in October. This suggests that births may occur around October, but the timing and location of pupping are not established across the species' range.

Breeding frequency: River shark species are reported to breed once a year or every 2 years, but species-specific information for the Northern River Shark is limited.

  • Size at birth is about 55 cm.
  • Young can use freshwater, estuarine and marine habitats.
  • No confirmed pupping site type should be assumed to be safe from project impacts.

Breeding habitat: Potential nursery habitat

Shallow, turbid, low-salinity reaches, tidal creeks and sheltered river margins are reasonable areas to treat as potential juvenile habitat. Maintain connections between these areas and deeper channels.

Avoid assuming that a small creek or freshwater reach is unimportant because adults are more often recorded in marine waters.

Confirmed breeding places: Specific pupping areas and breeding-place features have not been identified.

  • Shallow upper estuarine reaches
  • Freshwater to brackish transitions
  • Sheltered tidal channels and muddy margins
  • Floodplain channels connected to the main river

Breeding habitat: Works planning

Before in-water works, check records for juveniles and assess whether the project could disturb shallow nursery-like habitat. Consider timing, staging and methods that reduce turbidity, noise, channel blockage and accidental capture.

If a shark, juvenile or suspected pupping area is recorded, stop the activity that could cause harm and obtain advice from the relevant regulator or species specialist.

Protection level: Because the species is Endangered and has low reproductive output, any loss of mature animals or juveniles can be significant.

  • Keep construction plant out of the water where practicable.
  • Use exclusion and sediment controls around aquatic works.
  • Avoid trapping animals in isolated pools during dewatering.
  • Use a qualified aquatic fauna handler for any approved rescue or relocation.

Sheltering habitat: Likely refuge areas

No particular cave, burrow, hollow or roosting structure is associated with the Northern River Shark. Shelter is likely to be provided by the shape and depth of connected river, estuarine and marine habitats.

Potential refuge areas include deeper channel sections, turbid pools, tidal creek junctions and muddy margins with access to freshwater, brackish and marine waters.

The species is solitary and is not known to form schools. A lack of visible animals in a channel does not indicate that the habitat is unused.

Roosting signs: There are no known roosts, dens, nests or surface signs to search for.

  • Deep or sheltered sections of tidal channels
  • Turbid pools and bends
  • Creek junctions and river mouths
  • Connected muddy estuarine margins

Sheltering habitat: Disturbance from works

Dredging, pile driving, vessel traffic, bank works, dewatering and altered flows can displace animals or reduce access to refuge habitat. In-water noise and vibration should be managed as part of the aquatic fauna risk assessment.

Avoid creating isolated pools or temporary channels that could trap sharks as water levels fall.

Relocation: Do not attempt to capture or relocate a shark unless this is directed and authorised by the relevant authority.

  • Maintain free movement through connected channels.
  • Stage dewatering so animals are not stranded.
  • Use gradual drawdown where practicable.
  • Inspect isolated work areas before they are drained or enclosed.

Sheltering habitat: Field response

If a shark enters a work area, keep people and equipment clear, stop activities that could injure it and maintain an open route to deeper connected water where safe. Do not chase, net or feed the animal.

Record photographs, location, water conditions and the response taken. Report any injury, capture or death promptly.

Site status: A site near a suitable river or estuary should be managed as potential habitat unless a regulator or suitably qualified specialist supports a lower risk conclusion.

  • Keep workers out of the water unless entry is essential and approved.
  • Use trained personnel for any aquatic fauna response.
  • Follow the project's incident and threatened-species reporting procedure.

Threats: Habitat loss and modification

The main risks on development sites are loss or alteration of connected aquatic habitat, accidental capture and poor identification. The species is Endangered, so controls should be planned before works begin rather than relying on reactive rescue.

Clearing, bank hardening, dredging, reclamation, impoundment and access tracks can remove or alter shallow river, estuarine and tidal habitat. Barriers can restrict movement between freshwater, estuarine and marine areas.

Sediment plumes, changed salinity, reduced flows and pollution can affect prey and habitat quality even where the construction footprint does not reach the main channel.

Planning status: All known Australian river systems are considered important, and all populations are of high conservation value.

  • Map aquatic connectivity and tidal exchange before design is finalised.
  • Avoid unnecessary bank and channel disturbance.
  • Maintain fish passage and natural flow paths.
  • Use effective erosion, sediment and spill controls.

Threats: Fishing and accidental capture

Commercial and recreational gillnets, longlines and hook-and-line fishing can injure or kill Northern River Sharks. Illegal fishing and use of juveniles as bait are particular concerns in the Northern Territory.

Do not allow fishing gear in or near the work area unless it is specifically approved for a conservation or research purpose.

Legal protection: The species is Endangered under Commonwealth and Northern Territory legislation. Any take in the Northern Territory is illegal.

  • Brief all workers, contractors and vessel crews before mobilisation.
  • Remove or secure fishing gear from work boats and temporary facilities.
  • Report any capture, entanglement or shark part immediately.
  • Never retain, sell, move or deliberately harm the species.

Threats: Identification and reporting

Northern River Sharks are rare and can be confused with Bull Sharks and Speartooth Sharks. Fishing and incident records often do not identify sharks to species level, so photographs and accurate location data are valuable.

Treat a suspected animal or carcass as a protected species until identified by a suitably qualified person.

Regulatory advice: Seek project-specific advice from the Commonwealth and relevant state or territory authority before aquatic works in potential habitat.

  • Stop the activity that could cause further harm.
  • Keep people clear and do not handle the animal unless authorised.
  • Photograph the head, body, fins and colour pattern from a safe position.
  • Record the exact location, date, tide, water conditions and circumstances.

Threats: Controls for clearing and construction

For an Endangered aquatic species, use the avoid, minimise and monitor approach. Set out no-entry areas around connected waterways, keep plant and fuels away from the water and inspect temporary enclosures before dewatering.

Where suitable habitat cannot be avoided, obtain specialist advice on survey design, work staging, aquatic fauna observation and incident response. Do not claim the species is absent solely because a short survey finds no animals.

Survey intensity: Survey effort should be scaled to the Endangered listing, habitat connectivity and the type and duration of the proposed aquatic disturbance.

  • Complete a threatened-species risk assessment before mobilisation.
  • Use aquatic fauna observers for approved in-water works where required.
  • Stop works after a capture, injury or death until the response is agreed.
  • Maintain records of sightings, captures, controls and corrective actions.

Survey methodology: 1. Desktop assessment

The Northern River Shark is rare, difficult to identify and poorly known. Surveys should focus on large, turbid, tidal rivers, estuaries and connected marine habitats, particularly where works may alter water quality, flow, muddy substrate or fish passage.

Map all rivers, tidal channels, estuaries, floodplain connections and marine areas that could be affected by the project.

Search wildlife databases, fisheries records, museum records and local knowledge for Northern River Shark and other Glyphis records.

Treat records of unidentified river sharks cautiously. Northern River Sharks can be confused with the Speartooth Shark and Bull Shark.

Known Australian distribution: Northern Territory and Western Australia

Recorded habitat: Freshwater, brackish, estuarine and marine habitats, often in turbid and tidally influenced waters

Recorded salinity range: 2 to 36 parts per thousand for juveniles and subadults

  • Check whether the project is within or connected to known habitat in the Northern Territory or Western Australia.
  • Map upstream and downstream pathways, including temporary access routes, dredging areas, discharge points and changes to tidal exchange.
  • Refer to the Commonwealth threatened species profile and the relevant state or territory conservation authority before finalising the survey design.

Survey methodology: 2. Field detection survey

Use an experienced fisheries or elasmobranch ecologist to design the survey. There is no validated, species-specific survey effort that can reliably demonstrate absence.

Use non-lethal methods suited to the site, such as boat-based observation, carefully managed netting where lawful, baited remote underwater video and environmental DNA where the method has been validated for the catchment.

Do not use gillnets, longlines or other fishing methods unless they are lawful, specifically authorised and demonstrably suitable for threatened species work.

Known survey coverage: Previous broad surveys sampled 136 sites in 38 rivers but did not collect Glyphis specimens

Survey priority: Determine distribution and abundance across the Northern Territory and maintain connectivity between river systems

  • Survey during suitable tidal conditions when channels can be accessed safely and water remains representative of normal site conditions.
  • Repeat surveys where detection is likely to be low, especially in turbid water or where a single negative survey would affect the project decision.
  • Coordinate with fisheries authorities and local Traditional Owners before sampling rivers or estuaries.

Survey methodology: 3. Identification and specimen handling

Have any captured or observed river shark assessed by a qualified shark taxonomist. Do not rely on photographs alone where Northern River Shark and Speartooth Shark may occur together.

Record clear photographs of the dorsal, lateral and ventral surfaces, fins, head, teeth and any distinctive markings without unnecessarily restraining the animal.

Use DNA barcoding or other approved genetic methods when a reliable species identification is needed. Handle, release and sample animals only under the relevant authority.

Useful field features: Steely or slate grey above, abruptly white below, small eye, blunt rounded snout and a relatively large second dorsal fin

Maximum recorded size: Females 251 cm, males 144 cm, with reports of approximately 2 to 3 m overall size

  • Record total length, sex, life stage, capture location, date, time, tide, salinity, water depth, turbidity, temperature if measured, gear used and handling time.
  • Record whether the animal was released alive, injured or found dead.
  • Retain photographs, tissue records and chain of custody details for any approved diagnostic sample.

Survey methodology: 4. Reporting a detection

Stop work that could affect the animal or its habitat and notify the project ecologist and relevant regulator promptly.

Report captures, strandings, deaths and suspected illegal take to the relevant state or territory authority. Commonwealth reporting may also be required for a protected species interaction.

Share verified records with the relevant biodiversity or fisheries database so they can improve future decisions.

  • Provide the exact location, preferably with coordinates, and identify the waterbody and connected habitat.
  • Describe the activity underway and any likely effect on water quality, flow, noise, vessel movement or fish passage.
  • Keep the animal in the water and minimise handling while advice is obtained.

Before habitat disturbance: 1. Approvals and permits

Avoidance is the preferred approach for this endangered shark. Plan works around the river system rather than treating a work area as an isolated footprint, because animals may move between freshwater, estuarine and marine habitats.

Refer the action under the Environment Protection and Biodiversity Conservation Act 1999 where a significant impact on the Northern River Shark may occur. Obtain written advice before works begin.

Obtain all required fisheries, wildlife, scientific collection, animal ethics, waterway, dredging and pollution approvals from the relevant state or territory authority.

In Queensland, obtain a species management program where required for interference with a protected animal breeding place. Confirm the current Queensland requirements even though the mapped Australian distribution is in the Northern Territory and Western Australia.

Confirm any Western Australian or Northern Territory permit requirements for capture, handling, sampling, take, waterway works and protected species interactions.

Commonwealth status: Endangered under the EPBC Act

Northern Territory status: Endangered under the Territory Parks and Wildlife Conservation Act 1976

  • Do not assume that a project clearance or general fisheries approval permits handling of this species.
  • Include threatened species conditions in the construction environmental management plan.
  • Nominate a person responsible for regulatory notifications and stop work decisions.

Before habitat disturbance: 2. Avoidance and site design

Keep construction, dredging, piling, dewatering, spoil placement, vehicle access and discharge out of connected river, estuarine and tidal habitat wherever practicable.

Maintain natural flow, tidal exchange, muddy riverbed habitat, fish passage and water quality. Avoid barriers that could strand or concentrate sharks.

Use site-specific aquatic habitat protection zones. Set them from a risk assessment that considers the whole connected waterway, not only the bank or immediate work footprint.

  • Locate compounds, fuel stores, concrete washout, stockpiles and access tracks away from waterways and flood-prone areas.
  • Use sediment, erosion, spill and contaminated water controls before ground disturbance starts.
  • Avoid unnecessary night lighting over rivers, channels and estuaries.

Before habitat disturbance: 3. Pre-clearance and timing

Complete a targeted aquatic fauna survey before in-water works, particularly where the site connects to a large river, estuary or turbid tidal channel.

There is no confirmed species-specific breeding season or migration calendar. Use a precautionary approach throughout the year, and seek specialist advice where works may affect shallow freshwater or brackish habitat.

October records of free-swimming young suggest that births may occur around that time. Treat late winter and spring works as a higher-risk period where suitable pupping habitat may be affected, unless a qualified ecologist and regulator support another timing.

  • Survey after recent rainfall or changed flow only when safe, and record the conditions because detectability may change markedly.
  • Include upstream and downstream aquatic habitat in the assessment.
  • Do not clear or isolate aquatic habitat until survey findings and approvals have been reviewed.

Before habitat disturbance: 4. Induction and equipment

Induct all staff, contractors, vessel operators and spotter catchers on identification, legal protection, stop work procedures and reporting.

Use a trained aquatic fauna observer for works near water. A terrestrial spotter catcher cannot by themselves authorise capture or handling of a shark.

Prepare a contact list for the project ecologist, regulator, wildlife rescue service and approved fisheries specialist.

  • Carry waterproof identification material showing Northern River Shark, Speartooth Shark and Bull Shark differences.
  • Brief crews that deliberate capture or destruction is illegal in the Northern Territory and that any suspected interaction must be reported.
  • Inspect and clean equipment to prevent spread of weeds, pathogens, sediment and contaminants between waterways.

During habitat disturbance: 1. Sequential works and stop work

Treat any Northern River Shark interaction as a threatened species incident. Keep the animal in the water, reduce disturbance and stop the activity that may injure it until an authorised person has assessed the situation.

Stage works from already disturbed areas towards undisturbed areas, while maintaining a safe escape route to connected water.

Use a spotter or aquatic fauna observer during vessel movement, piling, dredging, dewatering and other in-water activities.

Give the observer authority to stop work immediately where a shark is seen, captured, stranded, injured or at risk of being isolated.

  • Stop pumps, suction equipment, dredging and machinery that could contact or trap the animal.
  • Lower vessel speed and propeller activity near a sighting where safe to do so.
  • Do not block a channel or leave an isolated pool without an approved aquatic fauna response.

During habitat disturbance: 2. Animal handling and active breeding places

Do not chase, net, lift, restrain or relocate a shark unless the person is authorised under the relevant permit and has the required specialist training.

If an active breeding place, pupping area or aggregation is suspected, stop the affected work and establish a temporary exclusion area based on advice from the project ecologist and regulator.

The species is solitary and no specific nest, colony, roost or breeding structure is known. Do not create an artificial breeding place or disturb shallow river habitat on the assumption that it is unused.

  • Keep people, boats and machinery away from the animal and reduce noise, vibration, lighting and turbidity where practicable.
  • Do not place barriers across the waterway unless they have been assessed and approved for aquatic fauna passage.
  • Restart work only after the authorised ecologist or regulator has documented the decision and controls.

During habitat disturbance: 3. Injured, stranded or dead animals

Call the approved wildlife or fisheries response contact immediately. Keep untrained personnel back and do not attempt treatment.

If safe, maintain water over the animal without moving it and prevent further contact with machinery, vessels or people.

For a dead animal, leave it in place unless an authorised officer directs recovery. Protect the location and preserve evidence of possible entanglement, collision or illegal take.

  • Record the exact location, condition, photographs, time, tide, water conditions and activity that may have caused the incident.
  • Do not remove gear, cut lines or alter the scene unless necessary to prevent immediate further harm or directed by an authorised officer.
  • Follow the regulator's instructions for release, sampling, carcass recovery and transport.

During habitat disturbance: 4. Incident records

Record every sighting, capture, near miss, injury, mortality and stop work event, including events involving an unidentified Glyphis shark.

Link the record to the work package, plant used, operator, observer and environmental conditions.

Notify the project manager and regulator within the timeframe required by the approval or permit.

  • Include coordinates, waterbody, date, time, tide, salinity if measured, turbidity, depth, animal size and photographs.
  • Record the response, people consulted, duration of the shutdown and controls applied.
  • Flag all uncertain identifications for expert review rather than recording them as a confirmed species.

After habitat disturbance: 1. Post-clearance aquatic checks

Post-work checks should confirm that no shark remains trapped or injured and that the project has not reduced aquatic habitat quality or connectivity. Review every interaction before similar work continues elsewhere on the site.

Inspect work areas, cofferdams, isolated pools, culverts, channels and dewatered sections before removing controls or filling the area.

Use an authorised aquatic fauna specialist where animals may have been trapped. Do not enter deep or tidal water without a safe method and approval.

Check for stranded, injured or dead sharks and other threatened aquatic fauna, and report findings as required.

  • Check downstream and upstream of temporary barriers and pumping points.
  • Confirm that fish passage and tidal exchange have been restored after temporary works.
  • Remove redundant barriers, netting, lines and debris that could entangle wildlife.

After habitat disturbance: 2. Relocated or released animals

Obtain written advice from the approving authority before any relocation. Relocation is not a routine mitigation measure for this species.

Where an authorised release occurs, record the release location, direction of release, animal condition, measurements, identification method and people involved.

Do not release an animal into an unconnected waterbody or outside the approved release area.

  • Use only an approved handling and transport method designed for live sharks.
  • Monitor the release area for immediate injury, abnormal behaviour or repeated stranding.
  • Submit photographs, samples and release records to the relevant authority and project database.

After habitat disturbance: 3. Monitoring and reporting

Complete any monitoring required by the approval, recovery plan or regulator. Focus on water quality, turbidity, flow, tidal exchange, fish passage and aquatic habitat condition.

Use repeat observations or approved remote methods where a project may affect known or potential habitat. Interpret non-detection cautiously because the species is rare and detection is difficult.

Provide a close-out report that compares the planned controls with what occurred in the field.

  • Report all confirmed and suspected interactions, including nil incidents where required by the approval.
  • Map changed habitat and retain before and after photographs.
  • Keep records available for audits and future environmental assessments.

After habitat disturbance: 4. Incident review

Review the cause of every interaction, including equipment failure, poor visibility, inadequate exclusion, incorrect identification or incomplete induction.

Update the construction environmental management plan, method statements and exclusion controls before restarting a similar activity.

Share lessons with the workforce and relevant regulators.

  • Check whether work timing, vessel movements, lighting, discharge or barriers should be changed.
  • Confirm that corrective actions have an owner and completion date.
  • Escalate repeated sightings, injuries or mortalities for independent ecological review.

Rehabilitation actions: 1. Restore aquatic habitat

Rehabilitation should restore connected aquatic habitat rather than provide terrestrial structures. The Northern River Shark uses rivers, estuaries and marine areas, and no suitable nest box, bat box or artificial roost structure has been identified for this species.

Reinstate natural channel form, tidal exchange, freshwater flows and fish passage after construction.

Stabilise banks with site-appropriate living vegetation and natural materials where this will not reduce channel capacity or create barriers.

Restore fine muddy substrate and turbid, tidally influenced habitat where those features were damaged, while avoiding uncontrolled sediment release.

  • Remove temporary causeways, cofferdams, pipes and barriers when no longer required.
  • Reconnect floodplain and side-channel habitat where approved and practicable.
  • Prevent scour, erosion, altered salinity and prolonged low oxygen conditions caused by the project.

Rehabilitation actions: 2. Water quality and weeds

Maintain sediment and erosion controls until the site is stable and water quality has returned to an acceptable condition.

Prevent fuel, concrete washout, chemicals, sewage and contaminated water from entering the river or estuary.

Control declared weeds and invasive species using methods that do not contaminate water or remove important bank cover unnecessarily.

  • Inspect drainage, discharge points and bank protection after rainfall and high tides.
  • Use clean fill and clean equipment in waterways.
  • Record water quality and habitat recovery observations during the approved monitoring period.

Rehabilitation actions: 3. Lighting, noise and ongoing disturbance

Remove temporary lighting and direct necessary permanent lighting away from the water surface and channel margins.

Limit vessel traffic, piling noise and repeated disturbance in restored habitat where practicable.

Keep maintenance activities within the approved footprint and reassess them if sharks or other threatened aquatic fauna are detected.

  • Use shielding, low spill lighting and timers where lighting cannot be avoided.
  • Maintain quiet refuge areas within the connected waterway.
  • Prevent new access tracks, moorings or barriers from fragmenting aquatic habitat.

Rehabilitation actions: 4. Artificial structures and long-term monitoring

Do not install nest boxes, bat boxes, artificial nests, roost structures or other terrestrial breeding structures for the Northern River Shark. These structures do not match the species' known biology.

Direct compensatory effort towards restoring river connectivity, water quality, tidal habitat and fish passage.

Monitor rehabilitated habitat for the period required by the approval, with additional monitoring if erosion, altered salinity, barriers or threatened species interactions occur.

Known breeding information: Live young have been recorded, including nine pups from one female, and free-swimming young have been found in October

Suitable restoration focus: Connected freshwater, brackish, estuarine and marine habitat, with natural flow, tidal exchange and fish passage

  • Use repeat habitat inspections and approved aquatic survey methods rather than relying on visual absence.
  • Record changes in channel condition, turbidity, salinity, flow, bank vegetation, fish passage and aquatic fauna observations.
  • Adapt rehabilitation measures if monitoring shows persistent habitat degradation or a new risk to the species.

Sources