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Flinders Ranges Mogurnda (Mogurnda clivicola)

The Flinders Ranges Mogurnda is a small freshwater gudgeon restricted mainly to permanent spring-fed pools and outflows in the northern Flinders Ranges of South Australia. Its habitat is scarce and depends on persistent groundwater discharge, so clearing, earthworks, altered drainage, groundwater use, sedimentation or fish transfers near springs can affect the species directly or downstream.

Conservation status

Commonwealth, EPBC Act 1999: Endangered.

Queensland, Nature Conservation Act 1992: Endangered.

Breeding season

The species does not have a fully defined annual cycle. Breeding is usually associated with spring and summer warmth, but monitoring shows that recruitment can occur opportunistically and after flood events.

Month values run from January to December. The seasonal pattern is indicative only because breeding can be opportunistic rather than confined to a fixed season.

  • Breeding, spawning and egg guarding: Spawning is reported in spring and summer, with water temperatures above 20°C. Egg masses were observed in May 2010, and males guarded and fanned eggs on rocky substrate.
  • Larvae and young fish: Larvae and juveniles can occur following spawning. Fish less than 20 mm were recorded at all monitoring times, and a large recruitment event followed a February flood.
  • Flood-linked local movement and recruitment: No regular migration is documented. Increased recruitment and possible local movement may follow substantial flow or flood events, including the February 2020 event described in monitoring.
  • Dry-period refuge use: Permanent spring pools provide refuge when surrounding ephemeral creek beds are dry and during drought. Hydrology risk therefore applies throughout the year.
  • Highest clearing risk: Clearing or aquatic disturbance is most likely to harm the species during spring and summer breeding, egg guarding and early recruitment, and after flood events. Permanent spring habitat remains sensitive in every month.

Identification

This species is a small, bottom-associated freshwater gudgeon found in clear, shallow spring habitats. Identification should be confirmed by an experienced freshwater fish ecologist where project decisions depend on presence or absence.

The supplied sources describe the species as a very restricted mid-water and bottom-dwelling fish. Field surveys recorded adults to 142 mm total length, with larvae and juveniles also present. No reliable weight range is provided in the supplied documents.

Body size: Up to 142 mm total length recorded.

Body position: Mid-water and bottom dwelling.

Water setting: Usually observed in clear, shallow spring-fed pools and creek outflows.

Identification: Field identification

The species is sufficiently distinctive in its isolated freshwater range that accurate identification is generally not expected to be difficult. In clear pools, initial visual counts can be followed by low-impact confirmation methods where required.

The 2010 survey used visual observation, followed where necessary by backpack electrofishing. Visual surveys were preferred in clear, shallow habitats because capture and handling can stress this restricted species.

  • Record photographs or video before attempting capture.
  • Use wet hands and minimise handling if fish must be removed from the water.
  • Keep captured fish in a container of site water and return them promptly.
  • Use an appropriately trained fish ecologist for confirmation and population work.

Identification: Similar fish and field signs

Juvenile Flinders Ranges Mogurnda may be confused with the introduced eastern gambusia, also called plague minnow or mosquitofish, by inexperienced observers. The species can also be distinguished from Spangled Grunter where both are considered during regional surveys.

There are no tracks, scats, calls, sloughs, nests or eyeshine to use as field signs. Useful evidence is the fish itself, repeated sightings in spring pools, guarded egg masses, larvae, or a concentration of small fish following flow or flood events. Males have been observed guarding and fanning eggs on rocky substrate.

  • Treat an unconfirmed visual record as requiring expert review where possible.
  • Check for introduced Gambusia holbrooki in accessible pools and downstream habitats.
  • Look for egg masses attached to hard substrate and adult males guarding them during breeding surveys.

Distribution

The strongest documented population information is from the northern Flinders Ranges in South Australia. Records from Queensland remain uncertain in the supplied sources and require taxonomic and field confirmation.

In South Australia, the species is known from the Balcanoona Creek system and tributaries in the northern Flinders Ranges. The documented natural population is at Weetootla Spring, with a translocated population at Nepouie Spring. Both sites are in the Lake Frome drainage.

The species occurs in spring-fed waters within ephemeral creek beds. Spring discharge maintains surface water after rainfall runoff has ceased.

State with confirmed extant populations: South Australia.

Bioregional setting: Northern Flinders Ranges, including Balcanoona Creek and Lake Frome drainage.

Documented strongholds: Weetootla Spring and Nepouie Spring.

Distribution: Queensland records

A single or small number of records from the Bulloo River basin have been provisionally attributed to this species. Several records from the Barcoo River catchment have also been suggested, but the taxonomic relationship to the Flinders Ranges populations remains unresolved.

For Queensland projects, do not assume that a Mogurnda record represents M. clivicola without specialist identification and appropriate genetic or taxonomic review.

Queensland occurrence: Possible Bulloo River occurrence, not confirmed in the supplied survey guidance.

Other suggested occurrence: Several Barcoo River records have been reported, but their identity and relationship to M. clivicola remain undetermined.

Distribution: Population size and trend

The 2010 assessment estimated approximately 4,000 fish across the two Northern Flinders Ranges populations. The total was similar to estimates made about a decade earlier, although the species remained restricted to two known populations.

A later monitoring study found fish abundant and healthy at Weetootla and Nepouie Springs during 2019 and 2020. Fish less than 20 mm were present at each sampling occasion, indicating ongoing recruitment.

Estimated total population: Approximately 4,000 individuals in the 2010 Northern Flinders Ranges assessment.

Weetootla occupied extent: About 4 km of spring-sustained intermittent pools.

Nepouie occupied extent: About 750 m of spring-sustained intermittent pools.

Recent monitoring: Fish were abundant at Weetootla and Nepouie in monitoring during 2019 and 2020.

Habitat: Water and geomorphic setting

The species depends on permanent or near-permanent freshwater in an otherwise dry region. Habitat loss can occur even where construction is outside the wetted pool, because spring flow, groundwater recharge, flood paths and downstream water quality maintain the occupied habitat.

Flinders Ranges Mogurnda inhabits permanent spring-fed pools in northern Flinders Ranges creek beds. The surrounding creeks may be ephemeral, but groundwater-fed springs continue to flow after rainfall runoff has stopped.

The occupied sites include shallow pools, intermittent pools sustained by spring flow, and flowing outflows. The 2010 report describes the Weetootla population over about 4 km and the Nepouie population over about 750 m.

  • Map springs, pools, outflows and downstream surface-water connections before works begin.
  • Include groundwater-dependent habitat and downstream areas in the project impact area.
  • Maintain natural spring discharge and avoid blocking, filling or diverting creek-bed pools.
  • Control sediment, contaminants and turbid runoff entering pools or spring outflows.

Habitat: Vegetation and structure

The supplied documents identify spring pools, rocky creek beds, hard substrates, algal growth and riparian vegetation as important habitat features. River Red Gum woodland can line nearby creek channels, although the fish is primarily dependent on the aquatic habitat rather than a particular tree community.

Occupied pools were associated with rocky or hard substrates. Fish-containing pools were often green, with dense algae covering the substrate and forming filamentous masses.

  • Retain aquatic and semi-aquatic vegetation around spring pools.
  • Avoid removing rocks, coarse substrate or bank structure used by fish and spawning adults.
  • Keep machinery, stock access and spoil storage away from pool margins and spring discharge points.

Habitat: Climate and elevation

The species occurs in an arid to semi-arid part of the Flinders Ranges where permanent groundwater-fed springs provide drought refuge. The supplied sources do not provide a confirmed elevation limit or a defined upper temperature limit for the species.

Water temperatures recorded at occupied spring sites ranged from about 14.9 to 27.2°C in the 2010 assessment. Monitoring across occupied pools recorded temperatures from 11.4 to 29°C.

Water temperature recorded at occupied sites: About 11.4 to 29°C across monitoring, with 14.9 to 27.2°C recorded at the two principal sites in 2010.

Hydrological dependence: Permanent spring flow maintains surface water through dry periods and drought.

Foraging habitat: Diet

The species feeds within shallow spring pools and associated outflows. Available observations indicate predation on aquatic invertebrates and tadpoles, but the supplied documents do not define a complete diet or foraging range.

Individuals were observed eating caddis larvae and tadpoles. In a field observation, ten tadpoles added to a pool containing about 20 fish were consumed within two minutes.

The species may therefore use both the bottom and the water column, consistent with its description as a mid-water and bottom-dwelling fish.

Recorded prey: Caddis larvae and tadpoles.

Observed feeding response: Ten introduced tadpoles were consumed within two minutes by about 20 fish.

Foraging habitat: Foraging habitat

Foraging occurs in spring-fed pools and outflows with shallow water, hard or rocky substrate and aquatic growth. Occupied pools were often associated with dense algae, which may provide cover and support aquatic prey.

No measured home range or routine foraging distance is provided. Keep the full pool and connected outflow intact rather than treating only the deepest water as habitat.

  • Protect shallow margins, rocky substrate and algal or aquatic growth.
  • Prevent sediment plumes and chemical discharges that could reduce aquatic prey or smother substrate.
  • Survey connected pools and outflows, not only the spring source.

Breeding habitat: Breeding biology

Breeding occurs in warm spring and summer conditions but can also be opportunistic. Substantial flow or flood events may produce strong recruitment, so breeding habitat can be used outside a narrow calendar window.

Egg masses have been observed on rocky substrate in spring-fed pools. Adult males guarded and fanned the eggs, and newly hatched larvae were observed schooling above a guarding male.

The 2010 report describes spawning in spring and summer when water temperatures exceed 20°C. Later monitoring found fish less than 20 mm at all sampling times and linked a substantial recruitment event to a flood in February 2020.

Breeding season: Typically spring and summer, with observations also showing opportunistic breeding after substantial flow or flood events.

Egg mass size: Approximately 600 to 900 eggs per observed mass.

Egg location: Hard or rocky substrate in spring pools.

Parental care: The male guards and fans the egg mass and protects newly hatched larvae.

Age at maturity: Not provided in the supplied documents.

Lifespan: Not provided in the supplied documents.

Incubation period: Not provided in the supplied documents.

Breeding habitat: Breeding habitat features

Breeding habitat requires persistent surface water, hard substrate for egg attachment, suitable water temperature and enough connected pool habitat for larvae and juveniles. Spring outflows are particularly important because they retain water when surrounding creek beds dry.

Flooding can stimulate recruitment, but works that alter flow paths, scour pools or introduce sediment may damage eggs, larvae and spawning surfaces.

  • Avoid clearing, excavation, dewatering and in-stream disturbance around occupied pools during warm months and after flow events.
  • Retain rocky spawning surfaces and shallow nursery margins.
  • Maintain spring discharge and safe passage between connected pools where fish currently occur.
  • Inspect occupied habitat for eggs, larvae and guarding males before any aquatic disturbance.

Sheltering habitat: Aquatic refuges

The species uses permanent spring pools as refuges in a dry region. The supplied documents do not describe terrestrial shelters, burrows or hollows because this is a fully aquatic fish.

Permanent spring-fed pools are the main refuge during dry periods, drought and periods when surrounding creek beds are not flowing. The species persists in spring-sustained pools within otherwise ephemeral creek channels.

Deep or persistent pools and connected spring outflows should be treated as habitat even when fish are not immediately visible.

Primary refuge: Permanent spring-fed pools and their flowing or pooled outflows.

Known occupied extent: Approximately 4 km at Weetootla and 750 m at Nepouie in the 2010 assessment.

  • Do not drain, isolate or fill spring pools.
  • Maintain groundwater discharge, pool depth and surface-water connectivity.
  • Keep vehicles, pumps, stock and construction materials out of occupied pools and their margins.

Sheltering habitat: Cover and handling

Algal growth, aquatic vegetation, rocky substrate and pool structure provide aquatic cover and feeding surfaces. The species is sensitive to handling, and its scales can be lost during capture.

There are no documented terrestrial dens, burrows, tree hollows, roosts or seasonal torpor sites for this species.

  • Retain algae, submerged structure and aquatic vegetation unless removal is authorised and supervised by a fish specialist.
  • Use visual survey methods first where water clarity permits.
  • If capture is required, minimise contact, keep fish in site water and release them promptly.

Threats: Hydrology and construction

The main risks are loss of permanent spring habitat, reduced groundwater or spring flow, drought, altered drainage, introduced fish and disturbance of small isolated populations. Effects can occur upstream, within the pool, or downstream through the spring outflow.

Both known South Australian populations depend on spring flow to maintain permanent surface water. Reduced flows and water-table decline have affected springs elsewhere in the Flinders Ranges, including springs that were greatly diminished or extinct during drought conditions.

Clearing, road construction, trenching, dewatering, groundwater extraction, drainage diversion and poorly placed crossings can reduce discharge, isolate pools, increase sediment input or change flood flows.

  • Identify the spring source, groundwater-dependent zone, occupied pools and downstream outflow before design finalisation.
  • Keep earthworks and access tracks away from spring discharge points and creek-bed pools.
  • Do not use occupied pools for water supply, vehicle access, washing, spoil storage or sediment settling.
  • Design drainage so clean water continues to reach existing pools without concentrating erosive flows.
  • Monitor spring flow, pool persistence, turbidity and water quality before, during and after works.

Threats: Introduced fish and biological threats

Eastern gambusia, also called plague minnow, is an introduced pest recorded at some Flinders Ranges sites. European Carp has also been introduced to the region. Both may spread through connected waters or through deliberate or accidental human movement.

Disease-like skin abnormalities and growths were recorded in the 2010 assessment. Abnormalities affected about 19.8% of fish at Weetootla and 12.3% at Nepouie, although the cause was not confirmed.

Recorded abnormality rate: About 19.8% at Weetootla and 12.3% at Nepouie in the 2010 assessment.

Introduced fish of concern: Gambusia holbrooki and Cyprinus carpio.

  • Prevent transfer of water, fish, mud and equipment between catchments and pools.
  • Clean and disinfect nets, traps, electrofishing equipment, boots and vehicles between sites under the project biosecurity plan.
  • Report suspected Gambusia or European Carp and do not release aquarium or bait fish.
  • Photograph abnormal fish and obtain specialist advice rather than moving affected individuals.

Threats: Drought, grazing and disturbance

The species is exposed to prolonged dry periods because its known habitat is concentrated in a small number of spring systems. The Flinders Ranges assessments identify drought, changed water flow, habitat loss, land use, grazing practice and feral animals as management concerns.

Fragmentation is particularly significant because the documented populations occupy short, isolated spring-fed reaches and may have limited opportunity for natural recolonisation.

  • Avoid removing riparian cover or destabilising banks around spring-fed pools.
  • Fence or otherwise manage stock access where trampling, fouling or bank collapse threatens occupied habitat.
  • Treat every occupied spring and connected outflow as high-sensitivity habitat during project planning.
  • Plan post-construction monitoring for fish presence, pool persistence, spring flow and introduced species.

Survey methodology: 1. Map habitat and plan the survey

Survey this fish wherever a project may affect permanent or semi-permanent spring-fed pools, creek pools or downstream flows in the northern Flinders Ranges, South Australia, and where records indicate possible Queensland occurrences. Define the project area and all upstream and downstream areas that may be affected before selecting methods.

Map all springs, pools, creek channels, wetlands, inflows, outflows and groundwater-dependent features in the project area and areas that could be affected downstream.

Record water permanence, flow, pool dimensions, connectivity, riparian vegetation, substrate, water quality and signs of recent flooding or drying.

Search government databases, threatened species records, recovery information, published literature, local experts and community groups for records in the project area and surrounding region.

Treat permanent spring-fed pools as high-priority habitat because the species is restricted to these habitats in the northern Flinders Ranges and depends on spring flow to maintain surface water during dry periods.

Known South Australian habitat: Permanent spring-fed pools and creek reaches associated with Balcanoona Creek and tributaries, including Weetootla and Nepouie springs.

Known South Australian occupied reach: About 4 kilometres at Weetootla Spring and about 750 metres at Nepouie Spring in the 2010 assessment.

Survey methodology: 2. Conduct low-impact visual searches

Search clear, shallow pools and stream reaches by observing fish from the bank or stream bed before using capture methods.

Count fish where practical and record the location, pool or reach length, water depth, water temperature, water clarity, behaviour, size classes, spawning activity and visible abnormalities.

Use visual searches as the first method because they can detect fish while avoiding capture and handling in restricted populations.

Search the full accessible spring-fed reach where the project could affect habitat, including upstream pools, downstream outflows and connected pools.

Detection notes: The species can be visually identified in clear, shallow stream habitats, and visual assessment was used to minimise sampling impacts.

Breeding evidence: Larvae, guarded egg masses and parental care have been observed; egg masses contained an estimated 600 to 900 eggs in the 2010 survey.

Survey methodology: 3. Use targeted capture only when needed

Use baited traps as the preferred capture method for this species where visual searches cannot confirm presence or where identification, abundance or population structure must be assessed.

Use backpack electrofishing only by appropriately trained operators, under the applicable Australian code of practice and permit conditions, and only at the level needed to confirm presence or collect required data.

Use backpack electrofishing in shallow flowing water, pools and wadeable reaches, with settings adjusted to local water quality and operated to minimise injury and habitat disturbance.

Keep captured fish in a container of water for the shortest possible time, handle them with wet hands and return them promptly to the capture location unless an authorised translocation or veterinary response is required.

Do not use boat-based electrofishing as a default method for this small freshwater fish group.

Preferred species-specific method: Baited traps.

Additional methods used in South Australian assessments: Visual counts and backpack electrofishing to confirm presence, estimate abundance, assess size structure and assess health.

Survey methodology: 4. Set timing and conditions around detection and disturbance

Survey during periods when the target water bodies contain water and include both spring-fed pools and downstream reaches that remain wet after creek flows subside.

Record recent rainfall, flooding, drought, water temperature and flow because breeding and abundance may change after flow events.

Do not assume that a negative result proves absence where habitat is dry, inaccessible, turbid or historically occupied.

Avoid unnecessary disturbance during spawning observations, and treat any larvae, eggs or guarding males as a reason to stop capture in that pool and review the survey method.

Breeding information: Recent studies found fish less than 2 centimetres total length at all sampling times, indicating that breeding may occur opportunistically rather than in a fixed season.

Observed breeding response: A substantial breeding event followed a flood in February 2020.

Published monitoring periods: May and August 2019, and June and August 2020.

Survey methodology: Minimum effort and reporting

There is no species-specific prescription in the supplied documents for a fixed number of survey nights, trap nights, hours, transect lengths or survey area, so set effort using the mapped habitat, project impact area, access and detection conditions and document the rationale.

Use an experienced fish ecologist or a suitably supervised survey team, especially where identification, electrofishing, abundance estimation or disease assessment is required.

Record every search and capture location, date, start and finish time, method, effort, weather, recent rainfall, water level and flow, water quality, habitat condition, species records, life stages and photographs where permitted.

Report positive and negative results, including survey limitations and dry or inaccessible habitat, to the project approval authority and the relevant state wildlife or biodiversity database.

Check current EPBC Act and state listing, permit and reporting requirements before fieldwork because the supplied guideline lists Mogurnda clivicola as EPBC Act vulnerable, while project records may show different current state classifications.

Before habitat disturbance: Avoid and minimise

Plan the project around the species' dependence on permanent spring-fed surface water. The highest-risk actions are removal of spring habitat, interruption of groundwater or surface flow, sediment or chemical pollution, and loss of connectivity between pools.

  • Redesign the footprint to retain permanent spring pools, spring vents, pool margins, creek beds, outflows and downstream pools.
  • Retain the groundwater source and the surface flow path that keeps pools wet during dry periods.
  • Keep machinery, stockpiles, refuelling areas, access tracks and spoil out of springs, pools, creek channels and riparian margins.
  • Maintain movement pathways between connected pools and do not install structures that isolate occupied pools or alter their depth, flow or water quality.
  • Treat any occupied spring-fed pool or connected outflow as high-value habitat and refer proposed disturbance to a qualified aquatic ecologist before approval.

Before habitat disturbance: Check approvals and plan the works

  • Check the current EPBC Act listing and determine whether the action needs referral because the species is nationally listed in the supplied records.
  • Check South Australian or Queensland wildlife, fisheries, national park, water and animal ethics requirements before surveying, capturing, handling or relocating fish.
  • Prepare a fauna and aquatic habitat management plan that identifies occupied and potential habitat, exclusion areas, flow protection, water quality controls, survey methods, stop-work triggers, response contacts and reporting requirements.
  • Stage works so that any unavoidable activity near water is completed in the shortest practicable window and does not coincide with observed eggs, larvae or guarding adults.
  • Obtain written approval from the relevant authority before any translocation, captive holding, salvage or release.

Before habitat disturbance: Prepare the site

  • Complete the pre-clearance aquatic survey before finalising access, drainage, dewatering or construction methods.
  • Mark spring vents, occupied pools, pool margins, flow paths, riparian vegetation and no-go areas on plans and on the ground.
  • Install exclusion fencing or equivalent barriers where they can prevent machinery and people entering retained aquatic habitat without diverting natural flow.
  • Brief operators and spotter catchers on the species' appearance, habitat, stop-work triggers, hygiene controls and incident procedure.
  • Keep an aquatic ecologist available during works that could affect water levels, flow, sediment or water quality.

During habitat disturbance: Daily controls and supervision

Use an aquatic habitat exclusion approach rather than treating this species as a terrestrial fauna rescue issue. The fauna spotter catcher must work with the aquatic ecologist and plant operator to prevent fish habitat from being entered, drained or contaminated.

  • Inspect exclusion fencing, flow controls, sediment controls, spill kits and no-go markers before work starts each day.
  • Confirm that springs and pools retain water and that inflows and outflows are not blocked, diverted, pumped or contaminated.
  • Keep machinery on approved access routes and stop work if vibration, excavation, dewatering, sediment, chemical spills or altered flows could reach occupied or potential habitat.
  • Use clean equipment between water bodies to reduce the risk of transferring pathogens, weeds or pest fish.
  • Have the spotter catcher and aquatic ecologist communicate directly with the operator using a clear stop-work signal and radio or phone contact.

During habitat disturbance: Fish encounters and handling

  • Stop the relevant activity if a fish, egg mass, larvae or guarding adult is found in or near the work area.
  • Do not catch, handle, hold, move or release the fish unless the person is authorised under the approval and permit conditions.
  • Keep any necessary handling to the minimum time, use wet hands, keep fish in water and return them to the capture location unless an approved relocation is directed by the relevant authority.
  • Relocate fish only to nearby retained habitat when an authorised aquatic ecologist confirms that relocation is approved, suitable and unlikely to spread disease or mix unsuitable populations.
  • Treat interstate records, including possible Queensland records, as requiring taxonomic confirmation before any management decision because the supplied documents identify uncertainty about relationships between Queensland and South Australian occurrences.

During habitat disturbance: Habitat features, injury and stop-work triggers

  • Do not apply hollow-bearing tree, log, rock or burrow salvage procedures to this fish unless those features directly affect aquatic flow or pool habitat.
  • Stop work immediately for unexpected fish presence, eggs or larvae, loss of spring flow, pool drawdown, fish stranding, visible pollution, sediment entering water, a chemical spill, fish mortality or damage to a marked exclusion area.
  • Place injured fish in clean, aerated water only under an authorised response plan and contact the nominated aquatic wildlife rehabilitator, veterinarian or government officer without delay.
  • Do not release an injured or unidentified fish without direction from the relevant authority or an appropriately qualified aquatic ecologist.
  • Prevent further harm, isolate the source of pollution or flow change, and record the incident before work resumes.

During habitat disturbance: Records and incident reporting

  • Record date, time, location, habitat, water level and flow, species life stage, number of fish, method of detection, photographs, handling, relocation, injury, mortality and the people who made each decision.
  • Record all stop-work events, permit conditions, corrective actions, water quality results, flow changes and clearance decisions.
  • Report deaths, injury, unauthorised handling, habitat damage, pollution and unexpected occupied habitat to the project environmental officer and approval authority within the required timeframe.
  • Submit confirmed records, including reliable negative survey records where requested, to the relevant state wildlife or biodiversity database.

After habitat disturbance: Complete post-work checks

Do not close out the fauna component when machinery leaves. Confirm that springs and pools still function, that no fish were stranded or harmed, and that retained habitat remains connected and clean.

  • Inspect all occupied and retained spring pools, outflows and connected creek reaches after each work stage and after reinstatement of drainage or flow controls.
  • Check for fish, larvae, egg masses, stranded fish, turbidity, sediment, spills, altered water levels, blocked flow paths and damaged riparian margins.
  • Remove temporary barriers only after the aquatic ecologist confirms that the site is stable and that removal will not divert or interrupt flow.
  • Complete a final aquatic fauna inspection before demobilisation and record any areas that could not be inspected.

After habitat disturbance: Monitor and report

Published population context: A 2010 assessment estimated about 4,000 fish across the Weetootla and Nepouie populations, similar to estimates from a decade earlier.

Published monitoring density: The Nepouie population was recorded at 5 to 50 fish per square metre, with a mean of 9.7 fish per square metre across 10 observations in April 2009.

  • Continue visual monitoring and, where approved, targeted low-impact surveys at affected and reference pools using consistent locations and methods.
  • Compare abundance, size classes, recruitment, visible health, water quality and habitat condition with pre-work results rather than relying only on presence or absence.
  • Use monitoring after major rainfall or flood events because recruitment may increase after substantial flows.
  • Report monitoring results, incidents, corrective actions, rehabilitation performance and any residual impact to the approval authority and relevant state database.
  • Apply an approved offset or other compensatory measure if residual impacts remain after avoidance, minimisation and rehabilitation.

Rehabilitation actions: Restore spring and pool habitat

Rehabilitation must restore the aquatic function that supports the fish, not just the surrounding vegetation. Prioritise permanent water, spring flow, pool structure, water quality and protection from pest fish and disturbance.

Recorded habitat setting: Occupied sites include spring-fed pools and intermittent pools in creek beds, with river red gum and other riparian vegetation recorded at surveyed reaches.

  • Reinstate natural or approved spring outflows, pool sequences, shallow margins and downstream connections where works have altered them.
  • Use clean, stable material that matches the existing bed and banks, and prevent new barriers that stop fish movement between pools.
  • Restore riparian cover and native aquatic or semi-aquatic vegetation appropriate to the local spring and creek community without introducing non-local stock or invasive species.
  • Do not fill, deepen, line or reshape pools unless the design has been assessed by an aquatic ecologist and approved by the relevant authority.
  • Protect groundwater recharge and discharge areas from compaction, contamination, excessive extraction and changed drainage.

Rehabilitation actions: Control threats and maintain habitat

  • Control sediment, weeds, livestock access and feral animal impacts that reduce water quality, damage pool margins or alter spring flows.
  • Prevent the spread of Gambusia holbrooki and European carp through public education, equipment hygiene, fish exclusion and early reporting of new records.
  • Do not stock or move fish into rehabilitated water without a formally approved conservation translocation plan.
  • Maintain fencing, spill controls, flow protection and access restrictions until monitoring shows that the site is stable.

Rehabilitation actions: Monitor success

Water quality recorded in occupied pools: Conductivity 1,141 to 13,800 microsiemens per centimetre, dissolved oxygen 1.9 to 12.0 milligrams per litre, temperature 11.4 to 29 degrees Celsius, pH 7.1 to 8.8, calcium 36 to 213 milligrams per litre and nitrate 0.2 to 17.7 milligrams per litre.

Health monitoring finding: The 2019 and 2020 monitoring study found fish abundant and healthy at Weetootla and Nepouie springs, with six or fewer fish showing skin lesions on each sampling occasion.

  • Set success measures for permanent or seasonally appropriate water, continuous or restored spring flow, stable pool habitat, acceptable water quality, intact riparian margins and no new pest fish records.
  • Repeat visual fish surveys at the same pools and reaches used before disturbance, and use authorised baited traps or backpack electrofishing only where additional data are necessary.
  • Record recruitment, including fish less than 2 centimetres total length, adult size classes, breeding observations, visible abnormalities and fish abundance.
  • Continue monitoring through dry periods and after substantial rainfall or flooding so that short-term occupancy is not mistaken for recovery.
  • Report failures promptly and repair flow, sediment, access or water quality controls before further works proceed.

Sources