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Dalhousie Mogurnda (Mogurnda thermophila)

The Dalhousie Mogurnda is a small, brightly marked gudgeon restricted to the Dalhousie Springs complex in South Australia. Works that alter spring flow, water quality, banks or visitor access may affect this isolated fish, which is listed as critically endangered under Commonwealth legislation.

Conservation status

Commonwealth, EPBC Act 1999: Critically endangered.

Breeding season

Dalhousie Mogurnda probably spawns throughout the warmer months in the Dalhousie Springs complex. Field timing is poorly documented, and breeding may extend beyond the warmer months because the species occupies permanent, warm spring waters.

Breeding mode: Egg laying. In aquarium observations, eggs are attached to the underside of a hard surface and guarded by the male.

Breeding sites: Natural spawning sites are not recorded. Aquarium spawning occurred on the underside of hard objects.

Egg number: About 200 to 800 eggs per spawning.

Incubation: Eggs hatch in about 7 days.

Young: Larvae are about 5 to 6 mm long at hatching. Fledging and weaning do not apply.

Age or size at maturity: Maturity is reached at about 60 mm.

Breeding frequency: Spawnings may be repeated while water temperatures remain above 20°C in aquarium conditions.

Timing may vary between years and among spring outlets, depending on water temperature, spring flow and local conditions; treat breeding as potentially year round where warm permanent water is retained.

  • Breeding and spawning: Spawning probably occurs through the warmer months, but no species-specific peak month has been established.
  • Eggs and newly hatched larvae: Eggs and larvae may be present during the warmer-month spawning period, with hatching taking about 7 days.
  • Adult presence in permanent spring habitat: The species occurs in permanent Dalhousie Springs habitat, so adults may be present in all months.
  • Highest clearing risk: In-water works and disturbance are most likely to affect spawning, eggs and larvae during the warmer months, although aquatic habitat should be protected year round.

Identification: Appearance and size

The Dalhousie Mogurnda is a stocky, thick-bodied gudgeon with vivid markings. Identification by appearance alone may require specialist fish expertise, so locality is an important part of the identification.

Adults can reach 150 mm in length. The body is cigar-shaped, with a darker back and a very pale belly.

The sides usually have dark red and light blue round spots, together with 10 or more irregular, light yellowish vertical bands. The cheeks have red stripes. The fins, apart from the pectoral fins, are brightly marked with red and blue tones, and the anal and second dorsal fins have an outer white band.

Maximum reported length: 150 mm

Body form: Stocky, thick and cigar-shaped

  • The mouth is reasonably large for the size of the fish.
  • The body is stocky rather than slender.
  • Handle any captured fish carefully and release it promptly at the point of capture, unless an approved salvage or translocation procedure applies.

Identification: Similar species

Other Mogurnda species can look very similar. The known Mogurnda species have separate geographic ranges, so a fish from the Dalhousie Springs area is more likely to be the Dalhousie Mogurnda, but confirmation should be by a suitably experienced aquatic ecologist or taxonomist.

The species is unlikely to be confused with most other fish of the Lake Eyre region when locality and body markings are considered together.

  • Do not rely on colour alone, especially in turbid water, poor light or photographs.
  • Record the spring, pool or channel where the fish was seen, with photographs where this can be done without disturbing the habitat.
  • Consider an approved environmental DNA assessment where visual identification is uncertain or where direct capture would add risk.

Identification: Calls and field signs

A diagnostic call is not available for field use. The species is a fish, so droppings, nests, whitewash, odour and roost stains are not useful search signs.

Look for live fish in permanent spring pools, channels and spring tails. Eggs of Mogurnda have been described in aquarium conditions on the underside of a hard object, but natural spawning sites for this species are not well defined.

  • Treat any Mogurnda sighting in the Dalhousie Springs area as potentially significant.
  • Stop or modify works if fish, eggs or an occupied aquatic feature are found, and obtain advice from the relevant land manager and threatened species authority.

Distribution: Australian range

The Dalhousie Mogurnda has an extremely restricted Australian range. For project planning, assume that suitable permanent water within the Dalhousie Springs complex may support the species unless current survey information demonstrates otherwise.

The species is endemic to the Dalhousie Springs complex in Witjira National Park, South Australia. The springs are part of the Great Artesian Basin and occur across an area of about 70 km².

About 100 individual spring outlets have been described in the complex, with about 80 still active. The species is not recorded from another Australian state or territory.

Mapped Australian state: South Australia

Known regional occurrence: Dalhousie Springs complex, Witjira National Park

  • South Australia, Dalhousie Springs and the surrounding mound-spring complex.
  • No overseas range is recognised.

Distribution: Local site planning

Map all spring outlets, pools, reed-lined channels, spring tails and connected wet areas before access, clearing or construction begins. A short distance from open water does not necessarily mean that a work area is separate from the aquatic system.

Confirm the current extent and condition of occupied or potentially occupied water with the park manager and a qualified aquatic ecologist before finalising the work footprint.

  • Keep plant, vehicle and machinery access out of spring water and wet margins unless specifically approved.
  • Use existing access tracks where possible and plan works to avoid bank erosion and sediment entry.
  • Seek Commonwealth and South Australian approvals before actions that may significantly affect the species or its habitat.

Habitat: Spring features to look for

The Dalhousie Mogurnda occurs in the isolated aquatic habitats of the Dalhousie Mound Springs complex. These are permanent, relatively fresh wetlands in an otherwise very arid landscape.

Potential habitat includes deep spring pools, reed-lined channels, damp saline flats and spring tails. The spring system is supplied by Great Artesian Basin groundwater, and many springs have water temperatures between 30°C and 46°C.

Look for clear or moderately turbid permanent water, submerged structure, aquatic plants and connected shallow channels. The species-specific preference for any one spring feature is not well established.

Reported spring water temperatures: 30°C to 46°C

Landscape setting: Great Artesian Basin mound springs in the arid interior

  • Active spring outlets and flowing tails.
  • Permanent pools with aquatic or emergent vegetation.
  • Reed-lined channels and wet margins connected to spring water.
  • Wet areas downstream of outlets that retain water through dry periods.

Habitat: Site assessment before works

An aquatic ecologist should inspect the full spring feature, not just the proposed construction footprint. Check upstream and downstream connections, flow, water depth, water quality, banks, vegetation and signs of recent drying.

Because the species is critically endangered and range restricted, use a precautionary approach where habitat is connected or the presence of fish cannot be ruled out.

  • Survey before ground disturbance, dewatering, trenching, bank works or changes to drainage.
  • Photograph and map spring outlets and wetland boundaries before works commence.
  • Record flow condition, water temperature, water quality and the presence of fish or other aquatic fauna.
  • Keep a clear incident process for spills, sediment releases, unexpected drying or fish mortality.

Foraging habitat: Likely feeding areas

The Dalhousie Mogurnda is considered carnivorous. It probably feeds on aquatic invertebrates and small fishes, although detailed feeding observations for the Dalhousie population are limited.

Potential feeding habitat includes spring pools, shallow channels, reed margins and spring tails where small aquatic animals occur. Submerged plants, stones, woody material and undercut edges may provide feeding surfaces or cover.

Do not remove aquatic vegetation, bed structure or bank cover simply to improve visibility or access. These features may support prey and shelter.

  • Inspect both shallow margins and deeper pools.
  • Look for aquatic invertebrates, small fish and intact submerged habitat.
  • Maintain flow between outlets, pools and spring tails where such connections exist.

Foraging habitat: Works controls

Sediment, wastewater, fuel, sunscreen, detergents and nutrient-rich runoff can reduce water quality and affect prey communities. Plan works so that dirty water cannot enter a spring, pool or channel.

Avoid activities that disturb the bed or banks unless they are authorised and a qualified aquatic ecologist has assessed the likely effects.

  • Use clean equipment and prevent mud transfer between water bodies.
  • Keep refuelling, chemical storage, vehicle washing and concrete work away from aquatic habitat.
  • Do not use soap or shampoo in the springs.
  • Use sediment and erosion controls that will remain effective during the full works period.

Breeding habitat: Breeding information

Detailed breeding information for the Dalhousie Mogurnda is limited. Aquarium observations for Mogurndas indicate that spawning can occur in warm conditions, with eggs attached to the underside of a hard surface and guarded by the male.

Mogurndas have spawned in aquaria at temperatures above 20°C and probably breed during the warmer months. Females have laid about 200 to 800 elongated eggs, each about 3 mm long, and the eggs hatched after about 7 days in aquarium conditions.

Maturity is reached at about 60 mm. These observations should not be treated as a confirmed breeding calendar or nest description for the Dalhousie population.

Aquarium spawning temperature: Above 20°C

Reported egg number: About 200 to 800

Reported hatching time: About 7 days

Reported maturity: About 60 mm

  • Potential attachment surfaces may include the underside of stones, firm vegetation, timber or other hard objects in the water.
  • Search gently around submerged structure and shaded margins if breeding habitat needs to be assessed.
  • Do not lift or move objects in the water during a breeding assessment without approval.

Breeding habitat: Protection during works

Avoid dewatering, bed disturbance, bank trimming and changes to spring flow while fish or eggs may be present. As breeding timing is not established for this population, plan around habitat protection rather than relying on a short seasonal exclusion period.

If eggs, guarding fish or a possible spawning surface are found, stop work in the immediate aquatic area and obtain specialist advice before proceeding.

  • Maintain water levels and spring flow.
  • Prevent sediment, chemicals and wastewater entering the habitat.
  • Use an approved aquatic fauna salvage procedure only where avoidance is not possible and approval has been obtained.
  • Document any breeding observation and report it through the project environmental management process.

Sheltering habitat: Features that may provide cover

Specific sheltering sites have not been defined for the Dalhousie Mogurnda. In practice, intact spring pools, vegetated margins and submerged structure should be retained as potential refuge habitat.

Potential refuge features include reed-lined margins, submerged plants, stones, firm woody material, deeper pool edges and undercut banks. Spring tails and connected channels may also provide cover and allow movement within the spring system.

Avoid assuming that shallow or vegetated water is unused habitat. Small fish may be difficult to see in dense plants, glare or turbid water.

  • Retain aquatic and emergent vegetation where possible.
  • Avoid removing stones, woody material or stable bank structure.
  • Keep water movement and connections between pools and channels intact.

Sheltering habitat: Access and disturbance

Vehicles, people, pumps and machinery can crush bank cover, increase turbidity and alter refuge habitat. Access to the springs should be limited to approved routes, with work areas clearly marked before mobilisation.

Do not use boats or fishing equipment in park water bodies. Equipment required for aquatic research must be washed before use in each water body.

  • Use the provided steps and approved access points where visitor access is relevant.
  • Fence or barricade sensitive wet margins during works.
  • Keep lighting, noise and repeated pedestrian access away from occupied water where practicable.
  • Inspect footwear, nets, pumps, containers and other equipment before moving between water bodies.

Threats: Groundwater drawdown and loss of flow

The Dalhousie Mogurnda has a very small range, so damage at one spring group can affect a substantial part of the species. Treat all spring water, wet margins and connected groundwater features as sensitive threatened species habitat.

Reduced Great Artesian Basin pressure, groundwater extraction, evaporation and climate-related warming can reduce spring discharge or cause springs to dry. Drying during warmer conditions increases the risk to fish confined to isolated water bodies.

Construction, bores, pumping and changes to groundwater use should be assessed for effects on flow, water level and water temperature.

  • Do not alter, drain or pump spring water without approval and specialist assessment.
  • Monitor flow, water level, water quality and fish condition where required by the project approval.
  • Report unexpected reductions in flow or drying immediately.

Threats: Water pollution and sediment

Swimming, camping, wastewater, detergents, sunscreen, insect repellent, fuel, nutrients and sediment can degrade spring habitat. Bank erosion can add fine sediment and damage channels and wet margins.

Prevent pollutants from reaching the springs during mobilisation, construction, maintenance and demobilisation.

  • Use bunding and spill response controls for fuels and chemicals.
  • Keep wastewater and wash-down areas away from aquatic habitat.
  • Stabilise disturbed banks and tracks promptly.
  • Stop work and contain any spill or turbid discharge.

Threats: Physical disturbance and access

Trampling by people, stock or feral animals can damage banks, vegetation and shallow habitat. Excavating springs, widening tracks or allowing uncontrolled visitor access can alter flow paths and increase erosion.

Plan access around the aquatic system, not just around the construction footprint.

  • Use designated tracks and access points.
  • Keep machinery out of water and wet margins.
  • Maintain signs and controls that prohibit diving, jumping, boats and fishing where required.
  • Inspect the site after rain, flooding and major visitor periods.

Threats: Introduced species and disease

Introduced fish and aquatic diseases may be serious risks to an isolated endemic fish community. Increased visitor access can provide pathways through boats, fishing gear, water containers, footwear and clothing.

Dalhousie Springs has been described as free of exotic fish, so prevention of new introductions is a high priority.

  • Do not move fish, plants, water, mud or aquatic equipment between water bodies.
  • Clean and dry nets, footwear, pumps, boats and containers before moving between sites.
  • Do not release aquarium fish, bait or other organisms.
  • Use approved hygiene and quarantine procedures for aquatic surveys and construction equipment.

Survey methodology: 1. Desktop assessment

Dalhousie Mogurnda is restricted to the Dalhousie Springs complex and is poorly known in the field. Survey the whole spring habitat that could be affected, including pools, channels and spring tails, and use methods that avoid altering flow, water quality or the bed and banks.

Map all springs, pools, channels, spring tails, wetlands and drainage lines within and downstream of the work area.

Check whether the site is within Witjira National Park, the Dalhousie Springs complex or another area connected to Great Artesian Basin spring flow.

Review bore locations, water extraction, proposed dewatering, access tracks, visitor use and any risk of changed spring discharge.

Use recent records and consult the relevant South Australian authorities and park managers. Treat any suitable Dalhousie spring habitat as potential habitat unless current survey evidence shows otherwise.

Survey methodology: 2. Field detection

Use experienced freshwater fish ecologists to undertake direct visual searches in clear, shallow water. Search pools, reed-lined channels, spring tails, margins and sheltered areas without turning over substrates unnecessarily.

Use low-impact netting only where authorised and where it can be done without damaging vegetation, disturbing eggs or changing the bed. Stop if threatened fish, eggs or a guarding adult are encountered.

Consider environmental DNA sampling where water disturbance must be minimised or visibility is poor. Use a validated species assay, include contamination controls and have uncertain results confirmed by a suitably qualified laboratory.

Do not use boats, fishing gear or unclean equipment in the springs. Any equipment used for aquatic research must be cleaned and disinfected before it enters another water body.

  • Survey permanent spring habitat in suitable daylight conditions and avoid sampling immediately after activities that could cloud the water.
  • Repeat searches when detection is reduced by poor visibility, high disturbance or unsuitable water conditions. The survey design should be set by the ecologist because species-specific effort and detection rates are not established.

Survey methodology: 3. Timing and survey effort

Dalhousie Springs has permanent water, so surveys should be planned around access, water clarity and the proposed disturbance rather than relying on a seasonal migration period.

Mogurnda species probably spawn during warmer months. Aquarium observations record spawning above 20°C, with eggs hatching in about 7 days, but natural breeding timing for Dalhousie Mogurnda is not established.

Allow enough visits to cover all potentially affected spring outlets and connected waterbodies. Increase effort where the work could affect groundwater pressure, spring flow, water quality or downstream habitat.

  • Survey before finalising the work footprint.
  • Schedule a repeat check as close as practicable to clearing or construction if the first survey is old, conditions have changed or the work could affect water flow.

Survey methodology: 4. Records and identification

Record the date, time, weather, water temperature, water clarity, flow, water level, spring outlet, habitat type, search method, effort and all equipment used.

Map every observation, negative search and eDNA sample. Record fish numbers where they can be estimated without repeated handling, together with size class, behaviour and signs of breeding.

Photograph fish only where this can be done without chasing or stressing them. Dalhousie Mogurnda can reach 150 mm and has red and blue spots, yellowish vertical bands and brightly marked fins, but locality and expert confirmation are important because Mogurnda species are similar.

Report uncertain identifications to a qualified fish ecologist and retain photographs, voucher information and laboratory records in the project file.

Before habitat disturbance: 1. Avoidance and approvals

Avoid all direct and indirect impacts on spring habitat wherever practicable. Obtain approvals before work starts and treat changes to groundwater, spring flow or water quality as potential impacts on a critically endangered species.

Redesign the footprint to avoid springs, pools, channels, spring tails, wetland vegetation and their groundwater sources.

Do not drain, fill, excavate, divert, shade, dam or obstruct spring habitat. Avoid activities that could reduce Great Artesian Basin pressure or alter spring discharge.

Seek approval under the Environment Protection and Biodiversity Conservation Act 1999 where the action may have a significant impact on this nationally listed species or its habitat. Obtain all required South Australian approvals and park permissions before entering or modifying habitat.

Confirm the applicable wildlife, national park, water, heritage and biosecurity requirements with the relevant authorities. Dalhousie Mogurnda is recorded from South Australia, not Queensland. If a related project is proposed in Queensland, obtain advice before work and use a species management program where required for protected wildlife or breeding places.

Before habitat disturbance: 2. Pre-clearance survey and breeding check

Complete the approved pre-clearance survey across the entire disturbance area and any connected water that could be affected by pumping, sediment, chemicals or changed flow.

Inspect hard surfaces and sheltered margins for eggs and look for a guarding adult. Eggs of Mogurnda have been observed on the underside of hard objects, are about 3 mm long and hatch in about 7 days in aquarium conditions.

Treat any occupied pool, channel or spring tail as a potential breeding place. Do not lift rocks, pipes or other objects to search for eggs unless the action has been specifically authorised and is necessary for the assessment.

Have a qualified aquatic ecologist define the no-go area and any hydrological protection area before construction. No standard species-specific buffer has been established, so set the buffer from the spring’s flow path, groundwater dependence and likely sediment, chemical, noise and vibration pathways.

Before habitat disturbance: 3. Exclusion and site controls

Fence and sign the approved exclusion area before machinery arrives. Keep workers, vehicles, stock, pets, waste and fuels out of spring water and wet margins.

Provide clean access routes and washdown facilities outside the aquatic habitat. Prevent mud, sediment, concrete washout, fuel, wastewater, sunscreen, insect repellent, soap and detergent from entering the springs.

Prohibit fishing, boats and swimming in work areas. Keep all construction materials, spoil, chemicals and refuelling points away from flow paths and drainage lines.

Use sediment and erosion controls that do not block spring discharge or cause water to pond, back up or change direction.

Before habitat disturbance: 4. Approvals, induction and stop-work plan

Nominate an aquatic fauna spotter catcher or fish ecologist with authority to stop work. Include that authority in the contract, site plan and daily pre-start.

Induct every worker on the species, its restricted distribution, the exclusion area, hygiene controls, spill response, reporting requirements and the prohibition on unauthorised handling.

Place the approval conditions, contact list, incident form and emergency response steps at the site office and in supervisor vehicles.

Agree the escalation pathway with the project ecologist, land manager and relevant regulator before disturbance begins.

During habitat disturbance: 1. Sequential clearing

Use a slow, supervised approach and keep water connected wherever possible. No worker should handle Dalhousie Mogurnda, eggs or aquatic habitat unless authorised under the project approvals and directed by the qualified aquatic ecologist.

Clear from the least sensitive landward areas towards the already inspected work area. Keep the aquatic exclusion zone intact until the ecologist confirms that the next stage is safe.

Remove vegetation, debris and structures only where approved. Do not disturb the bed, banks, hard surfaces or submerged objects that could hold eggs.

Stage dewatering, diversion and excavation so that water quality, spring discharge and fish movement are maintained. Stop if water becomes turbid, contaminated, stagnant or disconnected from adjacent habitat.

Keep machinery out of water unless the approval expressly allows entry and the aquatic ecologist is present.

During habitat disturbance: 2. Animal, egg and breeding-place response

Stop work immediately if Dalhousie Mogurnda, eggs, a guarding adult or an occupied breeding place is found in the disturbance area.

Do not chase, net, relocate, photograph at close range or touch the animal or substrate. Keep people and machinery back and prevent further changes to flow or water quality.

Contact the authorised aquatic ecologist and project supervisor. They must determine whether the work can be redesigned, whether the exclusion area must be enlarged and whether a regulator must be notified.

Only an appropriately authorised person may capture or relocate fish. Use a method approved for the site, maintain water quality and temperature, minimise handling and release fish only to an approved nearby location if relocation is legally permitted and ecologically justified.

During habitat disturbance: 3. Pollution, injury and emergency response

Stop the source of any spill without entering the spring. Keep contaminated material and runoff out of the water, notify the supervisor and follow the approved spill plan.

If a fish is injured, do not administer treatment or release it without direction. Keep the animal in suitable clean water only if an authorised aquatic fauna handler directs this, and contact the nominated wildlife or veterinary pathway.

Record and report fish deaths, injuries, egg disturbance, sediment release, altered flow, chemical entry, equipment failure and any breach of the exclusion area as incidents.

Escalate immediately where the incident may affect a critically endangered population or a nationally protected action.

During habitat disturbance: 4. Daily field records

Record the work stage, personnel, machinery, weather, water level, flow, water clarity, water temperature, inspection results, animal observations and any controls installed.

Record all captures, relocations, releases, deaths and injuries, including authority, method, time, location and outcome.

Take photographs of the work area and controls from fixed points where this can be done without disturbing fish or breeding habitat.

Have the fauna spotter catcher sign the daily clearance and incident records before the next work stage begins.

After habitat disturbance: 1. Post-clearance inspection

Do not close out the fauna component when machinery leaves. Check that spring flow, water quality, habitat connectivity and exclusion controls remain intact, then document outcomes and address any incident promptly.

Inspect the full work area, access routes, drainage controls and downstream habitat after each disturbance stage and at completion.

Check for stranded or injured fish, disturbed eggs, sediment deposition, bank collapse, changed flow paths, blocked outlets, fuel or chemical contamination and damaged exclusion fencing.

Remove waste and temporary materials without entering sensitive water unless authorised. Repair erosion and drainage controls before they fail.

Have the aquatic ecologist confirm that no further fauna search or rescue action is required.

After habitat disturbance: 2. Monitoring and reporting

Continue monitoring where the project has altered groundwater use, spring flow, water quality, shading, access or bank stability. The frequency and duration should reflect the risk and approval conditions.

Use the same observation points and methods where possible so that changes can be compared over time. Include direct observations and, where suitable, validated eDNA testing.

Report results, incidents, corrective actions, fish handling and any changed habitat condition to the proponent, land manager and relevant authorities as required.

Retain maps, field sheets, photographs, laboratory results, permits, approvals and sign-off records in the project environmental file.

After habitat disturbance: 3. Relocated or rescued animals

Inspect approved release areas after any relocation and confirm that water remains permanent, connected and suitable.

Record the release location, habitat condition, number and life stage of fish, time held, water used, handling time and any mortality.

Do not move animals between unrelated spring systems or release them outside the approved location. Do not undertake relocation as a substitute for avoidance.

Arrange follow-up checks where relocation was authorised, and report any mortality or evidence that fish have not persisted.

After habitat disturbance: 4. Incident review

Review every stop-work event, spill, fish injury, egg disturbance, unauthorised entry or flow change with the supervisor and aquatic ecologist.

Identify the cause and amend the method statement, exclusion controls, induction or emergency plan before work resumes.

Notify the relevant regulator where approval conditions or threatened species requirements may have been breached.

Use the review to update the project risk assessment and future survey and management plans.

Rehabilitation actions: 1. Restore water and habitat

Rehabilitation should restore the spring’s natural water regime and aquatic structure, not just replace disturbed ground. Design all works around the permanent groundwater connection and the very limited distribution of this species.

Reinstate natural spring discharge, shallow and deep water areas, channels, spring tails and wetland margins where they have been disturbed.

Remove temporary barriers, spoil, sediment and hardstand that block flow or disconnect pools. Do not deepen, straighten or excavate spring habitat unless approved as part of an ecological restoration design.

Use clean, local materials and retain stable submerged surfaces that can provide shelter and potential egg attachment sites.

Prevent future reduction in flow by managing bores, pumping, drainage and water use in accordance with approval conditions.

Rehabilitation actions: 2. Vegetation, weeds and erosion

Re-establish native wetland and bank vegetation appropriate to the spring community. Protect reed-lined channels and spring-tail vegetation during establishment.

Control weeds and invasive aquatic plants with methods that do not introduce chemicals or plant fragments into the water unless specifically approved.

Stabilise bare soil with low-impact erosion controls and keep sediment out of pools and channels.

Exclude stock, vehicles and unnecessary visitor access from recovering habitat. Maintain signs and access controls where they are needed to prevent trampling and contamination.

Rehabilitation actions: 3. Structures and lighting

Do not install nest boxes, bat boxes, artificial roosts or terrestrial breeding structures for this fish. These structures do not replace its aquatic habitat.

Where a hard surface or submerged structure used for breeding has been lawfully removed, ask the aquatic ecologist and regulator whether a like-for-like replacement is suitable. Install it only in an approved location and without obstructing flow.

Keep lighting away from pools, channels and spring tails. Use the lowest practical intensity, direct lights away from water and avoid lighting that attracts insects or alters fish behaviour.

Do not introduce artificial structures, substrates, fish or plants without ecological approval and biosecurity controls.

Rehabilitation actions: 4. Long-term monitoring

Monitor spring flow, water level, temperature, water quality, vegetation cover, erosion, invasive species and fish use at agreed fixed locations.

Repeat fish surveys using consistent methods and include breeding indicators such as eggs or guarding adults where this can be checked without disturbance.

Compare results with baseline observations and investigate any decline, drying, pollution, exotic fish detection or loss of habitat connectivity.

Keep monitoring until the ecologist and relevant authority agree that the restored habitat is stable and the approval obligations are complete.

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