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Macquarie Perch (Macquaria australasica)

The Macquarie Perch is an endangered freshwater fish of cool rivers, streams, lakes and reservoirs in south eastern Australia. On development sites, disturbance to pools, riffles, riparian vegetation, water quality, flow or fish passage can affect adults, spawning fish, eggs and young fish, including downstream populations.

Conservation status

Commonwealth, EPBC Act 1999: Endangered.

Victoria, Flora and Fauna Guarantee Act 1988: Endangered.

Australian Capital Territory, Nature Conservation Act 2014: Endangered.

Breeding season

Timing varies between catchments and depends on water temperature and flow. The table gives a typical pattern for Murray Darling Basin populations and should be adjusted using local records, survey permits and advice from aquatic fish specialists.

The recommended survey period for Macquarie Perch is March to September. Surveys should not be conducted throughout the breeding season from October to mid January where avoidance is practicable.

  • Movement to spawning habitat: Adults and sub-adults move from pools, reservoirs or other holding habitat into flowing rivers and feeder streams before and during spring spawning. Timing is linked to increasing day length, flow and water temperature.
  • Breeding and spawning: Spawning generally occurs from October to December over gravel, cobble or stones in shallow flowing water, when water temperatures reach about 16 to 16.5°C.
  • Eggs and young: Eggs drift downstream and lodge among gravel and cobble. Hatching takes about 10 to 11 days at 15 to 17°C, followed by larval and juvenile use of rocky spaces and connected downstream habitat.
  • Adult feeding and home site use: Adults and sub-adults are most active at dusk, dawn and at night, and use defined daytime home sites. Recorded movement in a reservoir averaged about 500 m per day and increased to about 1 km per day in winter.
  • Highest clearing risk: Risk is highest from October to January because adults are migrating or spawning and eggs, larvae and young fish may be using riffles, gravel beds and downstream habitat. Clearing, in stream works, sediment release, dewatering and barriers during this period can affect breeding and recruitment.

Identification

Macquarie Perch is a medium to large freshwater fish with a deep, laterally compressed body and a rounded tail. Identification should be confirmed by an experienced aquatic ecologist where threatened fish may be present, particularly in catchments containing other percichthyids.

Adults are generally black grey, bluish grey or olive brown on the back and sides, with a whitish underside. Juveniles may be distinctly mottled.

The species has large silvery white or white eyes, conspicuous pores around the eyes and on the snout, an obvious lateral line, a large mouth, a rounded tail and, in adults, a characteristic humped back.

The body is deep and laterally compressed rather than slender. Fish from Murray Darling Basin populations can be considerably larger than fish from east coast drainages.

Maximum reported length: About 465 to 550 mm in the Murray Darling Basin

Maximum reported weight: About 3.5 kg

East coast maximum reported length: About 180 mm

Identification: Distinguishing features

Use the combination of a deep compressed body, large pale eye, eye and snout pores, prominent lateral line, rounded tail and mottled juvenile pattern to separate Macquarie Perch from other freshwater fish encountered during aquatic surveys.

The species belongs to the family Percichthyidae and may occur with other large native or introduced predatory fish. Coastal and inland forms are geographically and genetically distinct, and some sources indicate that they may represent separate taxa. Record the capture location and retain clear photographs where taxonomic confirmation is needed.

  • Do not rely on colour alone, because colour varies from dark grey or black grey to bluish grey and green brown.
  • Do not treat a fish captured in a reservoir as evidence that spawning occurs there. Reservoir populations require access to suitable inflowing river habitat for breeding.
  • Handle captured fish as threatened fauna and use approved aquatic fauna survey and animal ethics procedures.

Identification: Field detection

There are no terrestrial field signs such as tracks, scats, calls, nests, sloughs or eyeshine. Presence is shown by live fish, remains, reliable records or survey detection.

Adults may be difficult to see during the day because they shelter near the bottom or within cover. Daytime snorkelling can detect adults and larvae in clear water, while fyke nets are particularly effective for young fish and boat based electrofishing can be more effective for larger fish.

For presence or absence surveys, the recommended survey period is March to September. Surveys should avoid the breeding period from October to mid January where possible.

  • Use fyke nets with mesh of 9 mm or less where Macquarie Perch are targeted, and set nets partly out of the water so trapped platypus and other mammals can breathe.
  • Use boat based or backpack electrofishing only under the Australian Code of Electrofishing Practice and minimise handling time.
  • In clear streams, inspect deep pools, undercut banks, emergent macrophytes, boulders, woody cover and connected riffles.

Distribution: National range

Macquarie Perch is endemic to south eastern Australia. Remaining populations are small, fragmented and geographically separated, with natural and translocated populations occurring in inland and coastal catchments.

In the Murray Darling Basin, the species occurs in upper catchments of southern New South Wales, the Australian Capital Territory and northern Victoria. New South Wales populations include the upper Lachlan, Murrumbidgee and Murray catchments. Victorian populations include the upper Goulburn, Broken, Ovens and Mitta Mitta catchments.

In the ACT, natural populations occur in the Murrumbidgee, lower Paddys and Cotter rivers, with translocated fish in parts of the upper Cotter, Molonglo and Paddys rivers.

Natural or historically natural east coast populations have been recorded in the Hawkesbury Nepean, Georges and Shoalhaven systems in New South Wales. The original Shoalhaven population is presumed extinct. South Australia is also reported as presumed extinct.

  • New South Wales: upper Lachlan, Murrumbidgee and Murray catchments, and the Hawkesbury Nepean system.
  • Australian Capital Territory: Cotter, Paddys and Murrumbidgee rivers, with additional translocated populations.
  • Victoria: Goulburn, Broken, Ovens and Mitta Mitta catchments, plus several stocked or translocated waters.
  • South Australia: presumed extinct.

Distribution: Bioregions and strongholds

The species has been recorded in the Sydney Basin, South Eastern Highlands, Australian Alps, New South Wales South Western Slopes, Riverina and Victorian Midlands IBRA bioregions.

Important remaining or recovering populations include the Cotter Reservoir and Cotter River, the upper Murrumbidgee River, parts of the Ovens catchment, Lake Dartmouth and the Yarra River. The upper Murrumbidgee population has a core reproducing distribution of about 85 km between the Yaouk Bridge area and Murrells Crossing, with occasional records farther downstream.

  • The Australian Alps Montane Grasslands and Heathlands conservation management zone identifies Macquarie Perch as an EPBC Act listed species that may be present.
  • The upper Murrumbidgee, Cotter and Ovens systems contain populations or sub-populations of particular relevance to project surveys.
  • Stocked and translocated records do not necessarily represent natural range, so determine population origin where this affects impact assessment.

Distribution: Population status

The species was once widespread and abundant, but underwent major declines from about 1920 to the 1960s. Remaining Murray Darling Basin populations are generally small, isolated and restricted to upper catchments or impoundments with access to spawning habitat.

Recent sources identify approximately 12 to 18 known populations, mainly in the Murray Darling Basin, with additional translocated coastal populations. Long term trends vary between populations, but declines, low recruitment and low genetic diversity remain concerns.

Known populations: Approximately 12 to 18

Upper Murrumbidgee core reproducing distribution: Approximately 85 km

Typical daily adult movement: About 500 m on average in Cotter Reservoir, increasing to about 1 km per day in winter

National trend: Historical major decline, with remaining populations fragmented and often declining or recruitment limited

Habitat: Overall habitat

Macquarie Perch is primarily associated with cool, clear freshwater systems, especially upper river reaches and tributaries. It can persist in reservoirs and lakes when suitable inflowing river habitat remains available for spawning.

Preferred habitat includes cool, shaded upland streams and rivers with deep rocky pools, slow flowing sections, riffles and substantial cover. Fish also occur in lakes and reservoirs, particularly where connected feeder streams provide spawning habitat.

The species is now concentrated in relatively well forested and less sediment affected upper catchments, although it historically occupied some lowland and slower flowing Murray Darling habitats.

  • Deep rocky pools with boulders, woody debris, aquatic vegetation or undercut banks.
  • Clear water with connected pools, riffles and shallow flowing reaches.
  • Inflowing streams and tributaries connected to reservoirs or lakes.
  • Intact or recovering riparian vegetation that provides shade, bank stability and sediment filtering.

Habitat: Habitat structure

Adults are generally solitary outside the spawning period and occupy bottom or midwater habitat near cover. Juveniles may form shoals and use smaller sheltered habitats within or beside pools.

Spawning and recruitment depend on connected riffles and gravel or cobble beds. Sediment that fills pools, reduces substrate variation or clogs spaces between rocks reduces habitat quality for eggs, larvae, juveniles and aquatic invertebrate prey.

  • Retain deep pools, rocky substrate, boulders, snags, undercut banks and aquatic vegetation.
  • Maintain shade and stable vegetated stream margins.
  • Prevent soil, spoil, ash, concrete washout and construction sediment from entering streams.
  • Maintain connection between adult holding habitat, spawning riffles and downstream egg and larval habitat.

Habitat: Climate and elevation

The supplied sources describe the species as a cool water fish of temperate south eastern Australia and do not provide a single national elevation limit. Habitat suitability is more closely linked to cool water, flow, shade, depth, substrate and connectivity than to a fixed elevation threshold.

Water temperature affects swimming performance, spawning and egg development. Swimming performance declines below about 16°C, while spawning generally occurs when water temperatures exceed about 16°C.

Foraging habitat: Diet

Macquarie Perch is a predator of aquatic invertebrates. Adults feed mainly near the bottom of rivers, pools, lakes and reservoirs, while young fish take small planktonic prey.

The diet includes freshwater prawns and shrimps, small benthic aquatic insect larvae, mayflies, caddisflies and midges. Yabbies, dragonfly larvae, zooplankton and molluscs are also eaten.

Older general accounts also record terrestrial insects and other aquatic invertebrates. Juveniles take zooplankton such as water fleas, rotifers and water mites.

  • Protect aquatic invertebrate communities by controlling sediment, pollutants, altered flows and riparian degradation.
  • Retain submerged woody cover, boulders, aquatic vegetation and undercut banks that support prey and provide feeding cover.
  • Avoid activities that cause prolonged turbidity or smother gravel and rocky substrates.

Foraging habitat: Foraging areas and movement

Adults use a relatively large along shore movement range and are unlikely to persist in small, discontinuous pools. In Cotter Reservoir, adults and sub-adults moved about 500 m per day on average, with movement increasing to about 1 km per day in winter.

Adults are most active at dusk, dawn and at night. During daylight they commonly remain at defined home sites near the bottom, cover or banks.

  • Survey and assess connected pools, shorelines, riffle margins, submerged cover and inflowing streams rather than isolated shallow puddles alone.
  • Consider both day and night activity when planning observations, but use daytime snorkelling where clear water allows safe visual detection.
  • Treat connected downstream habitat as part of the foraging area where works alter flow, turbidity or prey communities.

Breeding habitat: Breeding biology

Macquarie Perch breeds in shallow, flowing river sections associated with the downstream end of pools and the head of riffles. Breeding fish may migrate upstream from reservoirs or deeper adult habitat to reach suitable gravel and cobble spawning areas.

Fish gather in schools before spawning and undertake seasonal movements into flowing rivers or feeder streams. Eggs drift downstream after fertilisation and lodge among gravel and cobble in riffles or other fast flowing sections.

Larvae are about 7 mm long at hatching. They drift or swim downstream and use spaces among rocks and boulders during early development.

Breeding season: Generally October to December, with surveys recommended to avoid October to mid January

Spawning temperature: About 16 to 16.5°C or higher

Egg production: Approximately 31,000 to 32,000 eggs per kilogram of fish weight

Egg development: About 10 to 11 days at 15 to 17°C

Age at maturity: Both sexes generally mature by about 3 years or older, although some males may mature earlier

Lifespan: Reported maximum age is about 26 to 30 years; most fish are expected to live less than about 12 to 15 years

Clutch or litter size: No fixed clutch size is given; fecundity is reported by fish weight as eggs per kilogram

Breeding habitat: Spawning habitat

Spawning habitat consists of shallow flowing water over clean gravel, cobble or stones, commonly at the downstream end of pools, the head of riffles or in fast flowing river sections.

Reservoir populations need access to suitable inflowing river habitat. Dams, weirs, road crossings, low flows and natural barriers can prevent adults reaching spawning sites.

  • Protect riffles, gravel and cobble beds from sediment deposition, excavation, vehicle access and altered flow.
  • Maintain fish passage between deep adult habitat, reservoirs, tributaries and spawning reaches.
  • Avoid in stream works, dewatering, high turbidity and abrupt flow changes during October to mid January.
  • Assess downstream egg and larval habitat because eggs drift before lodging among gravel and cobble.

Sheltering habitat: Adult and sub-adult refuge

Macquarie Perch uses deep pools and structural cover for daytime refuge, resting and protection from predators. The sources do not identify a specific refuge diameter or minimum cover size.

Adults and sub-adults commonly remain near the bottom or in midwater close to deep rocky pools, boulders, woody debris, aquatic vegetation and undercut banks. They are most active at dusk, dawn and at night, and tend to stay at defined home sites during the day.

Reservoir fish may use deep water as refuge, but still require connected river habitat for spawning.

  • Retain deep pools and their bankside and submerged cover.
  • Avoid removing snags, boulders, undercut banks or emergent aquatic vegetation from occupied reaches.
  • Maintain water depth and flow connectivity between pools rather than creating isolated shallow sections.
  • Inspect clear pools and cover during daytime snorkelling only where conditions are safe and suitable.

Sheltering habitat: Egg and juvenile refuge

After spawning, eggs lodge among gravel and cobble in riffles. Newly hatched larvae and small juveniles use spaces among pebbles and boulders, while juveniles may occur in shoals.

Sediment that fills interstitial spaces can remove egg, larval and juvenile refuge and can reduce the aquatic invertebrate prey base.

  • Prevent fine sediment from covering gravel and cobble spawning beds.
  • Keep machinery, stockpiles, access tracks and disturbed banks away from the channel and connected drainage lines.
  • Use site specific erosion and sediment controls that remain effective during rainfall and high flows.
  • Treat riffles and downstream gravel beds as habitat even when adult fish are not observed there.

Threats: Sediment and water quality

Macquarie Perch is affected by several interacting threats. Construction and infrastructure projects can directly affect habitat, flow, water quality, fish passage and disease risk, including beyond the project footprint.

Sedimentation fills pools, reduces substrate variation, clogs spaces used by eggs and juveniles, smothers spawning sites and reduces aquatic invertebrate prey. Construction activities, roads, disturbed banks, fire affected catchments and poor erosion control can all increase sediment delivery.

Pollutants, low dissolved oxygen, altered temperature, ash, concrete washout, contaminated runoff and other water quality changes can harm fish, eggs, larvae and prey communities.

  • Keep disturbed soil, spoil, fuels, concrete washout and chemicals out of waterways and drainage lines.
  • Stage earthworks to minimise exposed soil and install sediment controls before disturbance.
  • Maintain riparian buffers and shade where practicable.
  • Monitor turbidity, temperature, dissolved oxygen and other project relevant water quality variables upstream and downstream of works.

Threats: Flow change and barriers

Dams, weirs, road crossings, culverts and other structures can block local movement and spawning migration. Water extraction and regulation can reduce the high flow events needed to maintain pools, riffles and passage.

Cold water releases from stratified impoundments can alter downstream temperature, dissolved oxygen, egg hatching, insect emergence, growth, swimming performance and reproductive behaviour.

  • Map all barriers and assess passage during the flow conditions relevant to spawning migration.
  • Avoid dewatering or isolating pools and riffles during fish movement or breeding periods.
  • Maintain environmental flows and avoid abrupt changes in discharge where works affect regulated rivers.
  • Design crossings to retain a connected channel and suitable fish passage under low and moderate flows.

Threats: Alien fish, disease and predation

Introduced carp, redfin perch, trout, gambusia, goldfish and weatherloach can compete for food and habitat, prey on Macquarie Perch or degrade habitat. Carp can increase turbidity and disturb aquatic vegetation.

Alien fish can spread diseases and parasites, including Epizootic Haematopoietic Necrosis Virus and Lernaea. Fish transfer, stocking, water movement and contaminated equipment can increase this risk.

Cormorants can take Macquarie Perch, particularly where fish congregate before spawning. Native and introduced predators may have greater effects where habitat is degraded or fish are confined.

  • Do not move live fish, water, mud or aquatic equipment between catchments without approved biosecurity controls.
  • Clean and disinfect nets, boats, electrofishing equipment, footwear and other gear between sites.
  • Report suspected diseased or unusual fish and follow relevant state biosecurity procedures.
  • Prevent new incursions of redfin perch and other alien fish into occupied or restored habitat.

Threats: Clearing, fire and fragmentation

Clearing riparian vegetation removes shade, increases bank erosion and water temperature, and reduces filtering of sediment and pollutants. Removing woody debris or altering banks reduces cover and habitat complexity.

Bushfire and poorly planned fire management can increase ash, sediment, organic matter and chemical inputs, reduce dissolved oxygen and remove riparian shade. Climate driven drought, warming, extreme rainfall and fire can compound these effects.

Small isolated populations have low genetic diversity and are more exposed to local extinction when habitat is fragmented or recruitment fails.

  • Avoid clearing riparian vegetation beside occupied or potentially occupied waterways.
  • Keep machinery and temporary access routes out of pools, riffles, banks and riparian buffers.
  • Plan prescribed burning, hazard reduction and fire trail works with aquatic habitat controls and post fire sediment management.
  • Assess indirect downstream effects, not only habitat within the construction footprint.

Threats: Fishing and handling

Overfishing contributed to historical decline, and accidental capture can still injure or kill fish. Electrofishing, nets and other survey methods can also cause harm if unsuitable equipment, mesh, set times or handling procedures are used.

The species is protected from take in relevant jurisdictions, and survey work should use experienced aquatic fauna personnel, approved methods and appropriate permits.

  • Do not retain, relocate or release Macquarie Perch without the required authority.
  • Use the least harmful effective survey method and minimise capture, air exposure and handling.
  • Check fyke nets regularly and provide an air space to prevent drowning of platypus and other non-target animals.
  • Record location, habitat, photographs and life stage for every confirmed detection.

Survey methodology: 1. Define the survey area and habitat

Macquarie Perch are endangered freshwater fish that use cool, clear rivers, streams, lakes and reservoirs. Survey the full area that may be affected, including downstream habitat, feeder streams and access routes that may increase sediment or alter flows.

Map the project footprint and all areas that may be affected directly or indirectly, including downstream reaches, tributaries, impoundments, access tracks and sediment pathways.

Map deep rocky pools, shallow flowing riffles, gravel and cobble beds, undercut banks, emergent macrophytes, boulders, woody debris and shaded riparian habitat.

Record whether habitat is suitable for adults, juveniles, spawning or recruitment, and whether barriers could restrict movement between pools and spawning areas.

Preferred habitat: Cool, clear water, deep rocky pools with cover, slow flowing reaches and shallow flowing riffles.

Spawning period: Generally October to December, with surveys avoided from October to mid January.

Survey methodology: 2. Fyke nets

Use fyke nets as a primary method for detecting Macquarie Perch, particularly young fish and recent recruitment.

Set nets in preferred habitat such as emergent macrophytes and undercut banks, and use mesh of 9 mm or less to reduce mortality.

Set nets partially out of the water so trapped platypus and other non-target mammals have an air space.

Check nets at appropriate intervals and minimise handling time, predation risk and exposure of captured fish.

Recommended mesh: 9 mm or less.

Best documented use: Detection of young-of-year and age 1+ fish.

  • Target February to April where practicable, while avoiding periods when water levels, safety conditions or project impacts make netting unsuitable.
  • Give particular attention to rising water levels, when fyke nets can work well for young-of-year Macquarie Perch.
  • Use fyke catch data to assess recruitment, because young-of-year and age 1+ fish can comprise approximately 93 percent of the catch in this method.

Survey methodology: 3. Electrofishing

Use boat-based electrofishing for larger fish in reservoirs and deeper river habitat, and backpack electrofishing in shallow, relatively confined pools and riffles.

Operate under the Australian Code of Electrofishing Practice and adjust the method to minimise injury, shock and delayed mortality.

Use electrofishing during the day in low-turbidity water where visibility is suitable, but recognise that fish may hide in clear water during daylight.

Do not rely on electrofishing alone in deep or fast-flowing habitat, where detection can be unreliable.

  • Provide flow-through water and adequate aeration for shocked fish before release.
  • Use trained operators who can identify Macquarie Perch and distinguish them from other native and introduced fish.
  • Record electrical settings, date, duration, area fished, water conditions, habitat sampled, fish captured and fish released.

Survey methodology: 4. Snorkelling and visual searches

Use daytime snorkelling in clear water to search for adults, juveniles and larvae without capturing fish.

Search deep rocky pools, cover, shallow feeder streams, riffles and gravel or cobble areas used for spawning.

Use visual methods alongside fyke nets or electrofishing because fish size, water depth, turbidity and behaviour affect detection.

  • Do not snorkel where flows, visibility, water quality, temperature or project hazards make the method unsafe.
  • Record the reach length or area searched, observation time, visibility, water depth, flow condition and habitat features.
  • Treat a visual non-detection as inconclusive where water is turbid, deep, fast flowing or structurally complex.

Survey methodology: Minimum effort and reporting

The supplied survey guideline gives the recommended season and methods but does not prescribe a universal number of nights, trap nights, hours, transects or survey area for every project.

Set effort according to the mapped habitat, project footprint, downstream risk, waterbody type, access and the objective of the survey, and document the basis for that decision.

  • Survey during March to September where practicable, and do not conduct routine surveys throughout the breeding season from October to mid January.
  • Use more than one method where practicable, with fyke nets for recruitment and boat or backpack electrofishing for larger fish.
  • Include downstream reaches and connected feeder streams where sediment, altered flows, barriers, pollution or water temperature changes could affect habitat.
  • Record all effort and conditions, including dates, start and finish times, method, net dimensions and mesh, number of nets, electrofishing settings, search area, visibility, flow, temperature, turbidity, captures and non-target fauna.
  • Submit confirmed records, including zero records and survey metadata where accepted, to the relevant state or territory wildlife and fisheries database.
  • Report suspected Macquarie Perch, disease signs, fish kills and new populations promptly to the relevant state fisheries or threatened species agency.

Before habitat disturbance: Avoid and minimise habitat loss

Plan works around the species' aquatic habitat and breeding movements. Avoid sediment, flow, temperature and passage impacts before considering capture or relocation.

  • Retain cool, shaded stream sections, deep rocky pools, undercut banks, boulders, woody debris, emergent macrophytes and intact riparian vegetation.
  • Retain shallow flowing riffles, gravel and cobble beds, feeder streams and other sites that may provide spawning or early life-stage habitat.
  • Avoid placing crossings, temporary dams, pumps, spoil, stockpiles or access tracks where they will block movement, fill pools, disturb riffles or increase sediment delivery.
  • Maintain connectivity between adult habitat, refuge habitat and upstream spawning areas.
  • Design works to prevent changes to flow magnitude, timing, duration, variability and temperature, including cold water pollution from impoundment releases.

Before habitat disturbance: Approvals and project controls

National status: Endangered under the EPBC Act.

Identified state or territory status: Endangered in the ACT and NSW, and threatened with an advisory status of endangered in Victoria.

  • Treat the species as an EPBC Act endangered species and obtain project-specific environmental advice on whether referral or approval is required before works proceed.
  • Check state and territory threatened species, fisheries, waterway, fish movement, capture, handling and translocation requirements before surveying or disturbing habitat.
  • Confirm local requirements for NSW, the ACT and Victoria, where the supplied documents identify endangered or threatened status and relevant management obligations.
  • Prepare a fauna and aquatic habitat management plan covering survey design, sediment and water-quality controls, fish passage, capture and release, disease hygiene, stop-work triggers, incident response and reporting.
  • Engage an aquatic ecologist and appropriately authorised fish survey personnel before works affect occupied or potentially occupied habitat.

Before habitat disturbance: Timing and site preparation

  • Schedule in-channel disturbance outside the October to December spawning period and the broader October to mid January survey exclusion period where practicable.
  • Stage works so that suitable aquatic refuge and connected habitat remain available while each work area is disturbed.
  • Complete the pre-clearance aquatic survey before isolating, dewatering, diverting or disturbing the channel.
  • Mark deep pools, riffles, gravel beds, undercut banks, macrophyte beds, riparian buffers and known fish passage routes on construction drawings and in the field.
  • Install sediment, erosion and flow controls before ground disturbance, and inspect them after rainfall and high-flow events.
  • Use exclusion fencing or other controls where they can prevent people, machinery or stock from entering retained riparian or aquatic habitat without diverting fish into unsafe areas.

During habitat disturbance: Daily controls and machinery exclusion

Keep machinery, sediment and altered flows away from occupied habitat. A fauna spotter catcher must work within the approved aquatic fauna procedure and must not improvise fish capture or translocation.

  • Hold a daily pre-start briefing covering mapped fish habitat, exclusion areas, flow controls, sediment controls, disease hygiene and the stop-work procedure.
  • Inspect erosion and sediment controls, pump intakes, temporary crossings, cofferdams, screens and discharge points before work starts each day.
  • Keep machinery, fuels, concrete washout, spoil, slurry and contaminated water out of the channel and riparian exclusion areas.
  • Prevent sudden changes in flow, dewatering, low dissolved oxygen conditions, turbidity, thermal pollution and pollutant discharge.
  • Use screened pump intakes and fish-safe isolation and dewatering procedures designed by the aquatic ecologist.
  • Stop work if controls fail, fish are stranded, fish are observed in the work area, water quality deteriorates, a blockage prevents movement or sediment enters retained habitat.

During habitat disturbance: Fauna spotter catcher and aquatic ecologist roles

  • Ensure the fauna spotter catcher has the required state or territory authority for fish capture and handling, and works under the direction of the project aquatic ecologist.
  • Keep the spotter catcher outside the machinery exclusion zone unless the work supervisor has made the area safe and the spotter catcher is authorised to enter.
  • Use a spotter catcher to watch isolated pools, pump screens, bypass channels, dewatered areas and disturbed margins for fish and other aquatic fauna.
  • Do not handle Macquarie Perch, operate electrofishing equipment or undertake translocation unless authorised personnel, approved methods, suitable equipment and required permits are in place.
  • Minimise capture, air exposure, handling, crowding and transport, and release fish only to approved, suitable retained habitat.

During habitat disturbance: If Macquarie Perch or other aquatic fauna is found

  • Stop the activity that could injure the fish and notify the site supervisor and aquatic ecologist immediately.
  • Keep machinery and personnel clear until the fish has been assessed and the approved response has been confirmed.
  • Do not move the fish unless the handler is authorised and the movement is permitted under the fauna management plan and relevant legislation.
  • If relocation is approved, place the fish in nearby retained, connected habitat with suitable flow, depth, cover and water quality, or follow the approved translocation protocol.
  • Place injured fish in suitable aerated holding water only under the direction of the aquatic ecologist, and arrange assessment by an aquatic veterinarian or authorised wildlife rehabilitation provider where required.
  • Report dead or distressed fish, unusual lesions, disease signs, fish kills and suspected Epizootic Haematopoietic Necrosis Virus promptly, and apply the approved hygiene and biosecurity response.

During habitat disturbance: Records and incident response

  • Record the date, time, location, habitat, activity, water conditions, species, number and life stage of each fish encountered.
  • Record capture, handling, release, injury, mortality, relocation location, photographs, identifying features and the names and authorities of personnel involved.
  • Record every stop-work event, sediment release, barrier failure, fish stranding, pump-screen incident, disease concern and corrective action.
  • Notify the relevant regulator and land or water manager when an incident exceeds the approved impact limits or threatens a listed population.
  • Maintain daily records with the project environmental officer and include them in the final environmental report.

After habitat disturbance: Post-clearance and reinstatement checks

Do not treat completion of construction as the end of the fish protection obligation. Confirm that aquatic habitat, passage and water quality have recovered and that controls remain effective.

  • Complete a post-clearance inspection of every isolated, dewatered, diverted or disturbed reach before demobilisation.
  • Check pools, riffles, gravel beds, macrophytes, undercut banks, woody cover, riparian margins, pump areas and downstream sediment deposits for stranded or injured fish.
  • Remove temporary barriers, pipes, screens, spoil and sediment controls only when the aquatic ecologist confirms that removal will not release sediment or block fish passage.
  • Confirm that the final channel retains suitable pool depth, riffle structure, cover, shading, flow and connectivity.
  • Repair erosion, sediment controls and disturbed riparian areas promptly.

After habitat disturbance: Monitoring and reporting

  • Monitor water quality, sediment movement, flow, fish passage, habitat condition and Macquarie Perch recruitment where the project may have affected occupied or potential habitat.
  • Use fyke nets, electrofishing and other approved methods selected by the aquatic ecologist, with effort and timing recorded so results can be compared over time.
  • Continue monitoring for a period specified in the approval or fauna management plan, with additional surveys after major rainfall, fire, dewatering or flow events where relevant.
  • Compare results with pre-work survey data and report captures, mortalities, injuries, new records, recruitment, habitat damage and corrective actions.
  • Submit confirmed species records and required monitoring data to the relevant state or territory database and regulator.
  • Implement approved offsets or compensatory habitat actions where residual significant impacts remain after avoidance and mitigation.

After habitat disturbance: Maintain controls

  • Keep exclusion fencing, riparian protection, erosion controls, fish passage structures and access restrictions in place until the environmental officer confirms that the site is stable.
  • Prevent stocking, release or movement of alien fish and maintain equipment hygiene to reduce the risk of spreading Epizootic Haematopoietic Necrosis Virus and parasites.
  • Keep retained habitat free from recreational fishing impacts where required by the approval or local regulations.

Rehabilitation actions: Restore aquatic and riparian habitat

Rehabilitation should restore the functions Macquarie Perch need: cool shaded water, deep pools, flowing riffles, clean gravel and cobble, cover, food resources and movement between feeding and spawning areas.

  • Replant disturbed banks with locally native riparian vegetation to provide shade, bank stability, cover and filtering of sediment from runoff.
  • Re-establish deep pools, shallow flowing riffles and varied bed structure using stable rock, gravel and cobble appropriate to the reach.
  • Retain or reinstate large woody debris, boulders, undercut banks and aquatic vegetation where these features do not create a flood or safety hazard.
  • Prevent fine sediment from filling pools, clogging spaces between rocks or smothering gravel spawning substrate.
  • Design rehabilitation to maintain access between pools, riffles, feeder streams, reservoirs and other spawning habitat.

Rehabilitation actions: Passage, flow and water quality

  • Remove, modify or bypass barriers where feasible, and provide fish passage at crossings, weirs and other structures that restrict spawning movement.
  • Maintain environmental flows that support pool and riffle condition, spawning access and seasonal movement.
  • Prevent cold water pollution, low dissolved oxygen releases, abrupt flow changes, salinity, algal blooms and other water quality changes.
  • Use sediment and erosion controls on roads, batters, stock access points, fire management areas and construction areas within the catchment.
  • Design wet areas and drainage so they do not become sediment traps, isolated warm pools or pathways for polluted water into occupied habitat.

Rehabilitation actions: Alien fish, disease and fire management

  • Monitor for Redfin Perch, Carp, Brown Trout, Rainbow Trout, Gambusia, Goldfish and other alien fish, and implement approved removal or containment actions if they are detected.
  • Do not stock alien salmonids in Macquarie Perch habitat.
  • Apply equipment cleaning and disinfection procedures between catchments and sites to reduce disease and parasite transmission.
  • Plan prescribed burning, fire trails and post-fire erosion controls to protect riparian shade, water quality, spawning riffles and clean substrate.
  • Control weeds and manage stock or vehicle access where they cause bank erosion, loss of shade or sediment delivery.

Rehabilitation actions: Success measures and monitoring

  • Set site-specific success measures for riparian plant establishment, bank stability, sediment reduction, pool and riffle condition, passage function and water quality.
  • Monitor whether Macquarie Perch use the rehabilitated habitat and whether young-of-year fish are present, because recruitment is a direct indicator of breeding habitat function.
  • Repeat approved fish surveys during March to September and avoid routine surveys from October to mid January unless the management plan requires otherwise.
  • Monitor alien fish, disease indicators, habitat condition and flow performance at the frequency specified in the approval or rehabilitation plan.
  • Adapt rehabilitation if monitoring shows continuing sedimentation, loss of spawning habitat, blocked movement, poor recruitment or invasion by alien fish.

Sources