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Clarence Galaxias (Galaxias johnstoni)

The Clarence galaxias is a small, scaleless freshwater fish endemic to isolated high-altitude lakes, marshes and streams in central Tasmania. It is endangered because its former range has contracted and remaining populations are exposed to predation and competition from introduced trout, making protection of fish-free waters and their catchments important during development works.

Conservation status

Commonwealth, EPBC Act 1999: Endangered.

Tasmania, Threatened Species Protection Act 1995: Endangered.

Breeding season

The species is non-diadromous and remains in freshwater throughout its life. The documents give a spring breeding period but do not provide precise monthly timing, so the seasonal pattern below uses broad Tasmanian spring and early summer periods.

Monthly timing is indicative only because the supplied sources specify seasons rather than calendar months. Any works in occupied or potentially occupied habitat require site-specific assessment and the relevant permits.

  • Breeding: Spawning occurs in spring. Eggs are attached to rocks in lower stream reaches and inflows; the documents do not define exact months.
  • Young: Eggs take about 42 to 52 days to hatch in captivity, and larvae swim in open-water schools before juveniles become benthic at about 40 mm.
  • Movement or dispersal: The species completes its life cycle in freshwater and is not described as migratory. Fish may spread into other habitat when water levels are high enough.
  • Highest clearing risk: Spring spawning and the following egg and larval period are the most sensitive documented stages. Disturbance to rocky spawning reaches, inflows, pools or open-water nursery habitat should be avoided during this period.

Identification

The Clarence galaxias is a small to medium-sized, scaleless galaxiid with a stout body and blunt, rounded head. It is usually found close to the bottom or among cover as an adult, although larvae and small juveniles swim in open water.

Adults are usually dark brown on the back, with brown bars, irregular bands and blotches extending down the sides. The colour becomes lighter towards the underside, which is commonly yellowish or silver-yellow. Numerous small black spots may be visible, but these are parasites in the skin rather than natural markings.

Body form: Small to medium-sized, stout and tube-shaped, with no scales.

Maximum length: Approximately 120 to 140 mm.

Fin position: The anal fin begins below the middle of the dorsal fin.

Identification: Distinguishing features

The species can resemble the climbing galaxias, Galaxias brevipinnis, which occurs in the same general area. A live Clarence galaxias has a rounded, blunt head with jaws of approximately equal length, a yellowish belly, smaller pectoral fins and short, stout gill rakers. The climbing galaxias has a flatter, wedge-shaped head, a distinctly shorter lower jaw, larger rounded pectoral fins and longer, slender gill rakers.

Pectoral fin rays: Usually 10 to 13 in Clarence galaxias, compared with 13 to 16 in climbing galaxias.

Adult body position: Benthic, commonly near the stream, marsh or lagoon bed and among cover.

  • Do not rely on colour alone when identifying fish in the field, because colour varies with age and conditions.
  • Use an experienced freshwater fish ecologist or approved identification protocol where Clarence galaxias may occur.
  • Handle, net, photograph and release fish only under the applicable permit and animal ethics requirements.

Identification: Field signs

There are no reliable tracks, scats, calls, nests, sloughs or eyeshine associated with this species. Detection depends on finding the fish in suitable freshwater habitat, usually by careful electrofishing, scoop-netting or other approved fish survey methods.

  • Survey likely habitat rather than relying on incidental observations from banks or roads.
  • Treat deep pools, rocky cover, marsh margins and permanent inflow streams as potential habitat until assessed by a suitably qualified freshwater ecologist.

Distribution

The Clarence galaxias is endemic to Tasmania and has not been recorded outside the state. Its known distribution is concentrated in isolated waters of the central Tasmanian highlands and upper Derwent catchment.

The species occurs in small, isolated parts of the upper Derwent catchment, including the Nive, Clarence and Little River subcatchments. It is also associated with the upper Clarence River catchment and nearby central plateau waters. The original distribution is uncertain, but the species was formerly recorded from the lower Clarence catchment and disappeared from the type locality, Brown Marsh Creek, after brown trout became established.

Australian state range: Tasmania only.

Regional range: Upper Derwent catchment, including the Nive, Clarence and Little River subcatchments, in central Tasmania.

Bioregional information: The supplied documents describe the central Tasmanian highlands and central plateau, but do not assign the species to a named IBRA bioregion.

Distribution: Strongholds and subpopulations

The largest populations reported in the 2006 to 2010 recovery plan are at Clarence Lagoon and Johnsons Lagoon. Other known or reported populations include Wentworth Hills, Dyes Marsh, an unnamed lagoon upstream of Clarence Lagoon, Tibbs Plain in the Derwent catchment and other headwater waters in the Nive, Little River and Clarence systems.

Population count in 1987 to 1989 survey: Five populations.

Population count in 2006 to 2010 recovery plan: Seven known populations.

Population count in Inland Fisheries Service fact sheet: Six isolated populations.

  • Clarence Lagoon supports a population occurring with brook trout, which the recovery plan regarded as a relatively benign alternative to brown trout for the local fishery.
  • Most other populations are isolated from other fish species and are protected from trout by waterfalls, fluctuating water levels or other barriers.

Distribution: Population status

The species has undergone a substantial reduction in range. It is absent from the lower Clarence River catchment where it was first described, and it does not occur in waters colonised by brown trout. The supplied documents do not provide total abundance estimates or a population density. They identify continuing risk of decline if brown or rainbow trout invade remaining sites.

  • Do not assume that an apparently suitable waterbody is unoccupied: populations are highly fragmented and surveys have found additional sites over time.
  • Protect the occupied waterbody and the upstream and downstream catchment processes that maintain its barriers and water quality.

Habitat

Clarence galaxias habitat includes high-altitude lakes, lagoons, marshes and streams. Sites are generally permanent or seasonally secure freshwater habitats that remain free of brown trout and other predatory fish.

Adults occupy stream, marsh and lake habitats. Deep pools are preferred, although fish may spread into other areas when water levels are high enough. The species can use both flowing and still water, so habitat assessment should include inflow streams, marshes, lagoons, lake margins and connected headwaters.

Habitat types: High-altitude lakes, lagoons, marshes and streams.

Preferred feature: Deep pools, with access to other habitat during higher water levels.

Habitat condition: Occupied sites are generally free of other fish, except brook trout at Clarence Lagoon.

  • Map all waterbodies, inflow streams, outflow channels, marshes and wet depressions within and downstream of the project area.
  • Assess barriers, waterfalls, culverts and other features that currently prevent trout movement.
  • Maintain fish passage conditions for native galaxias while preventing movement of introduced trout into occupied habitat.

Habitat: Catchment and physical features

All occupied areas and the catchments affecting them are considered habitat critical to survival in the recovery plan. Populations are limited downstream by brown trout, rainbow trout or physically unsuitable habitat. Works that alter barriers, water levels, drainage, sediment movement or riparian and instream cover may increase the risk of trout colonisation or reduce habitat quality.

  • Avoid introducing or transferring any fish, water, mud or equipment that could carry trout between catchments.
  • Control sediment and avoid infilling, draining or isolating marshes, pools and inflow channels.
  • Refer proposed works near occupied waters, barriers or catchment headwaters to the relevant Tasmanian authorities and species specialists.

Habitat: Elevation and climate limits

The supplied documents identify the habitat as high altitude and central Tasmanian highland or plateau country. They do not provide a lower or upper elevation limit, temperature limit or quantified flow requirement.

  • Use local habitat and fish records rather than an assumed elevation threshold when screening a project area.
  • Treat permanent or semi-permanent highland freshwater habitat within the known range as potentially suitable until surveyed.

Foraging habitat

The Clarence galaxias feeds throughout its freshwater habitat, with a shift from open-water feeding as a larva or small juvenile to bottom-associated feeding as it grows.

Larvae and small juveniles feed on planktonic crustaceans while swimming in open water, often in small schools. At about 40 mm, juveniles begin to develop adult colouration and take on a benthic habit. Larger fish browse or feed near the bed on benthic crustaceans and aquatic insects.

Larval and juvenile prey: Planktonic crustaceans.

Larger fish prey: Benthic crustaceans and insects.

Foraging shift: At approximately 40 mm, juveniles begin to develop adult colouration and become benthic.

  • Retain open-water areas, shallow margins and backwaters used by larvae and small juveniles.
  • Protect rocky bottoms, pool edges and other benthic habitat used by larger fish.
  • Prevent sediment inputs and contaminants that could reduce aquatic invertebrate prey.

Foraging habitat: Foraging area

The supplied documents do not give a home range, feeding territory or movement distance. As the species completes its life cycle in freshwater and populations are isolated, feeding habitat is likely to be contained within the occupied stream, marsh or lagoon system, but the exact scale has not been quantified.

  • Survey connected pools, stream reaches, marsh edges and lake margins rather than a single point at the waterbody.
  • Retain cover and natural substrate across the occupied reach, including areas used by benthic invertebrates.

Breeding habitat: Breeding biology

Clarence galaxias breeds in freshwater during spring. Eggs are attached to rocks in lower stream reaches, and larvae later occupy open water before moving to bottom habitat as juveniles grow.

Egg masses have been found adhering to rocks, including in lower reaches of a stream flowing into the Wentworth Hills lagoon. Captive observations recorded eggs deposited under rocks resting directly on aquarium gravel. Larvae hatch into open water and form schools.

Spawning season: Spring.

Egg number: Approximately 300 to 2,000 large, strongly adhesive eggs.

Egg size: Approximately 1.6 mm.

Incubation: Approximately 42 to 52 days at 4 to 12 degrees Celsius in captivity; earlier descriptions give about two months.

Larval size at hatching: Approximately 8 mm.

Age at maturity: Not stated in the supplied documents.

Lifespan: Around four years.

  • Protect rocky stream margins, submerged rocks and lower inflow reaches during spring and the egg and larval period.
  • Avoid dewatering, sediment deposition, vibration, bank disturbance and changes to flow or water quality near likely spawning reaches.
  • Use a suitably qualified freshwater fish ecologist to determine whether eggs or larvae are present before works in occupied habitat.

Breeding habitat: Breeding habitat features

Spawning habitat includes rocks in lower stream reaches and rocky areas associated with lagoon inflows. The required features of natural spawning sites are not fully known, and the wild spawning site has not been identified for every population.

  • Retain permanent flow and submerged rocky substrate in occupied inflow streams.
  • Maintain the connection between spawning reaches, larval open-water habitat and juvenile benthic habitat.
  • Do not remove or rearrange rocks in likely spawning areas without specialist advice and approval.

Sheltering habitat

Adult Clarence galaxias shelter near the bed and among cover in pools, streams, marshes and lagoons. The species does not construct dens, burrows, nests or roosts.

Adults commonly live near the river or lake bed and among cover. Deep pools are preferred, and rocks or marginal cover provide shelter. Larvae and small juveniles use open water before changing to a benthic habit at approximately 40 mm.

Adult refuge: Stream, marsh or lagoon bed, including deep pools and cover.

Larval refuge: Open water, where larvae and small juveniles may form schools.

Known refuge dimensions: No den, burrow, hollow or refuge dimensions are provided.

  • Retain deep pools, submerged rocks, woody or marginal cover where present, and undisturbed bed structure.
  • Avoid dewatering or isolating pools during construction and temporary access works.
  • Keep machinery, spoil, sediment and concrete washout away from occupied water and connected drainage lines.

Sheltering habitat: Site protection

Because populations are isolated and downstream limits are often set by trout or unsuitable habitat, a refuge can depend on the condition of the surrounding catchment and barriers. Damage outside the wetted channel may still affect sheltering habitat through altered runoff, sediment or fish access.

  • Inspect upstream and downstream barriers before works begin and prevent their removal or bypass.
  • Maintain riparian vegetation and stable banks where they support cover or protect pool habitat.
  • Use fish exclusion and salvage procedures only under an approved method prepared by a qualified fish ecologist.

Threats: Introduced fish

Introduced trout are the dominant threat to Clarence galaxias. Development can increase this threat indirectly by damaging barriers, changing hydrology, degrading water quality or enabling unauthorised fish movement.

Brown trout prey on and compete with Clarence galaxias, and the species is not known to persist where brown trout have colonised. Rainbow trout are also a threat, with heavy predation observed at Johnsons Lagoon. Redfin perch are identified as a likely additional threat if introduced.

  • Do not stock or release fish, bait or aquarium contents into any project waterway.
  • Prevent transfer of fish, wet equipment, sediment and water between catchments.
  • Protect natural and artificial barriers that exclude trout, and report suspected illegal fish introductions immediately to the relevant authority.

Threats: Clearing and construction impacts

The Inland Fisheries Service identifies disturbance to riparian vegetation and instream habitat as reasons for the species' reduced distribution. Clearing, crossings, excavation, bank damage, sedimentation, dewatering and altered drainage can reduce cover, spawning substrate and invertebrate prey, or make trout movement easier.

  • Avoid clearing riparian vegetation and disturbing stream beds, marshes, lagoon margins and inflow channels.
  • Keep works, access tracks, stockpiles and spoil outside occupied water and its contributing drainage wherever practicable.
  • Design crossings and temporary works to avoid creating a pathway for trout or disconnecting native fish habitat.
  • Prepare a site-specific aquatic fauna management plan before works in or near known or potential habitat.

Threats: Hydrology, fragmentation and fire

The documents do not quantify the effects of roads, fire or particular hydrological changes on Clarence galaxias. They show that populations rely on isolated waters, permanent water, suitable barriers and catchments affecting occupied habitat. Changes to flow, water level, drainage or barrier function may therefore increase exposure to trout or reduce available habitat.

  • Assess direct and downstream effects of road crossings, culverts, water extraction, discharge, impoundment and drainage changes.
  • Maintain permanent pools and inflow connections used for breeding and juvenile development.
  • Assess fire planning, post-fire runoff and emergency access where these could increase sediment or alter stream and marsh habitat.

Threats: Disease and handling

The supplied documents do not identify a specific disease outbreak in Clarence galaxias. Black spots commonly seen on adults are described as skin parasites rather than natural colour markings. Handling, electrofishing and transfer can still cause stress or spread aquatic pathogens if hygiene controls are poor.

  • Use clean, disinfected equipment between catchments and follow approved fish handling and biosecurity procedures.
  • Minimise handling time and release native fish at the capture site unless a permit-approved translocation is in place.
  • Record unusual lesions, mortality or parasite loads and refer them to the relevant fish health authority.

Survey methodology: 1. Electrofishing in streams and marshes

Clarence galaxias is a small, freshwater fish restricted to isolated high altitude lakes, marshes and streams in central Tasmania. Surveys must cover aquatic habitat and likely trout entry points, and must be conducted by appropriately authorised personnel.

Use backpack electrofishing in suitable streams, marshes and shallow lake margins to detect Clarence galaxias and estimate population size and structure.

Operate equipment in accordance with the Australian Code of Practice and use settings and handling methods that minimise harm to fish.

Identify fish promptly and return Clarence galaxias to the capture location unless a permit or approved translocation plan authorises another action.

Known habitat: High altitude lake, marsh and stream habitats.

Adult size: Usually greater than 70 mm and up to approximately 140 mm.

Life span: At least four years.

  • Survey deep pools, stream margins, marsh channels, cover and inflow areas because adults use stream, marsh and lake habitats.
  • Record the sampled reach, habitat type, water conditions, effort, captured species, size classes and evidence of trout or other introduced fish.
  • Use a qualified freshwater fish surveyor with the required animal ethics, collection and electrical fishing approvals.

Survey methodology: 2. Scoop-net and visual searches

Use small scoop nets with visual searches where electrofishing is unsuitable, including shallow margins, cover and small stream sections.

Daylight generally assists identification and release, but night sampling can improve detection for some galaxiids and should be considered where safe and authorised.

Spawning period: Spring.

Egg development: Approximately one to two months in field observations; 42 to 52 days in captivity at 4 to 12 degrees Celsius.

Juvenile habitat shift: Juveniles develop adult colouration at about 40 mm and then move towards benthic habitat.

  • Search open water for larvae and small juveniles, which may swim in schools, and search the bed and cover for benthic adults.
  • Inspect rocks and submerged cover because eggs are deposited in masses adhering to rocks in stream reaches.
  • Use small plastic traps only as a supplementary method because catch rates can be low for galaxiids.
  • Avoid disturbing habitat more than necessary and disinfect equipment between catchments or sites to reduce the spread of aquatic pathogens and pest fish.

Survey methodology: 3. Habitat and introduced-fish inspection

Survey all aquatic habitat that could be affected directly or indirectly, including upstream and downstream areas connected to the works.

Treat brown trout and rainbow trout access as a survey priority because Clarence galaxias is not known to persist where trout become established.

Known distribution: Upper Clarence, upper Derwent and Nive catchments, including small isolated populations.

Population information: The 2006 to 2010 recovery plan recorded seven known populations, while an Inland Fisheries Service factsheet records six isolated populations.

Downstream limit: Known populations are generally limited downstream by brown trout and/or physically unsuitable habitat.

  • Map streams, marshes, lagoons, deep pools, inflows, outflows, barriers and areas of suitable cover before sampling.
  • Inspect for brown trout, rainbow trout, brook trout and redfin perch, and record barriers that may prevent or allow fish movement.
  • Extend the assessment beyond the construction footprint where sediment, altered drainage, barriers, dewatering or fish movement could affect occupied habitat.
  • Use the current Tasmanian species records and survey information to check for known populations and potential habitat before finalising the survey design.

Survey methodology: Minimum effort and reporting

Set survey effort from the size and connectivity of the affected aquatic habitat, the likely indirect impact area and the need to sample all habitat types and fish barriers.

  • Obtain advice from the Tasmanian Inland Fisheries Service before setting the final method, effort and release arrangements.
  • For a known population, plan at least two population surveys each year where the recovery program requires ongoing viability assessment.
  • Survey all five natural populations when the project affects the Clarence galaxias sites covered by the earlier recovery program, unless the responsible authority approves a different design.
  • Record date, start and finish time, coordinates, reach length or area, method, operator, equipment settings, weather, water conditions, effort, catch, fish sizes, photographs and introduced-fish observations.
  • Submit confirmed records and negative survey results to the relevant Tasmanian wildlife or fisheries database and provide the survey report to the approval authority and Inland Fisheries Service.
  • Report any new population, trout detection, barrier failure, fish mortality or injured Clarence galaxias to the responsible authority immediately.

Before habitat disturbance: Avoid and minimise

Plan the project around avoiding aquatic habitat loss and preventing trout access. Clarence galaxias populations are small, isolated and dependent on habitat that remains free of brown trout and other harmful introduced fish.

Avoid direct disturbance to occupied streams, marshes, lagoons, deep pools, inflows, outflows and their contributing catchments.

Retain natural barriers, riparian vegetation, stream cover, rocks, pools and wetland connections that help maintain fish habitat and exclude trout.

Critical habitat approach: All occupied areas and catchments affecting known populations should be treated as habitat critical to survival unless shown otherwise.

Main threat: Predation and competition from brown and rainbow trout.

  • Keep machinery, spoil, fuel, concrete washout and sediment out of the aquatic habitat and its drainage lines.
  • Maintain connectivity between occupied habitat patches unless a carefully assessed barrier is required to prevent trout movement.
  • Do not create a new fish passage connection from trout-occupied water to Clarence galaxias habitat.
  • Design crossings, culverts and drainage so they do not increase trout access, cause fish stranding or remove pools and cover.
  • Use the smallest practicable disturbance footprint and retain a vegetated riparian buffer sized by the site assessment and approval conditions.

Before habitat disturbance: Approvals and work planning

Clarence galaxias is listed as Endangered under the EPBC Act and under Tasmania's Threatened Species Protection Act 1995.

Confirm whether the action requires an EPBC Act referral, Tasmanian approval, fish collection or handling permits, animal ethics approval, reserve approval or other fisheries authorisation before works begin.

Commonwealth status: Endangered.

Tasmanian status: Endangered.

Spawning: Spring, with eggs taking about one to two months to hatch.

  • Engage the relevant Commonwealth and Tasmanian regulators early where habitat clearing, stream alteration, dewatering or fish handling may affect the species.
  • Prepare a species-specific aquatic fauna management plan covering survey results, exclusion zones, sediment controls, fish rescue, dewatering, stop-work triggers, incident response and reporting.
  • Stage works so that aquatic disturbance is limited to the shortest practicable period and does not coincide with spring spawning or egg and larval development where the authority considers timing restrictions necessary.
  • Use an approved fish ecologist or authorised fisheries officer for capture, identification, relocation and release decisions.
  • Include a method for preventing movement of trout, other fish, sediment and contaminated water between catchments.

Before habitat disturbance: Pre-clearance preparation

Complete the aquatic pre-clearance survey before finalising the construction boundary, access tracks, temporary crossings, drainage and dewatering areas.

Mark occupied habitat, potential habitat, stream buffers, fish barriers, spawning substrate, deep pools and no-go areas on plans and on the ground.

Recognition: Adults are dark brown above with bars and blotches, a yellowish or silver-yellow belly and no scales.

Key size for identification: Young fish begin adult colouration at about 40 mm.

  • Install exclusion fencing or clearly marked aquatic protection zones where they will prevent machinery, spoil and workers entering retained habitat.
  • Fence or otherwise protect wetlands, lagoons, stream margins and inflows from stockpiles, vehicle access and accidental drainage.
  • Confirm that temporary pumps, hoses, cofferdams and fish screens will not strand or entrain fish.
  • Train all workers and fauna spotter catchers to recognise the species and to identify brown trout, rainbow trout and other fish that may threaten it.
  • Keep rescue equipment, aerated holding containers, measuring equipment, nets and approved release equipment ready before any in-water work.

During habitat disturbance: Daily controls and machinery interface

Keep aquatic habitat protected throughout the works. The fauna spotter catcher supports the aquatic ecologist and does not replace the approvals, fish handling permits or specialist authority required for this species.

Conduct a daily pre-start inspection of exclusion zones, sediment controls, stream flows, fish screens, pumps, barriers and access points.

The fauna spotter catcher must remain in communication with the machine operator and direct the operator to stop before machinery enters any aquatic exclusion zone or approaches retained habitat.

Primary operational risk: Trout invasion or introduction into remaining fish-free habitat.

Other risks: Predation or competition by rainbow trout, redfin perch and other introduced fish, plus habitat disturbance.

  • Keep plant, refuelling, chemicals, concrete, spoil and wash water outside retained aquatic habitat and its drainage pathways.
  • Use clean, inspected equipment and prevent transfer of water, mud, fish, eggs and aquatic plants between waterbodies.
  • Control turbidity, flow diversion, vibration and bank collapse so that downstream pools, marshes and stream cover remain usable.
  • Use screened, low-velocity pumps and check them regularly during dewatering.
  • Do not discharge turbid, contaminated or fish-bearing water into Clarence galaxias habitat without approval.

During habitat disturbance: Fish capture, handling and relocation

If fish are found in the work area, stop the relevant activity and notify the aquatic ecologist and site environmental officer.

Only an authorised person may capture, identify, hold, transport or release Clarence galaxias, and all actions must follow the permit and approved fauna management plan.

Adult diet: Mainly benthic crustaceans and insects.

Larval diet: Planktonic crustaceans.

Relocation constraint: Release sites must be free of brown trout and other fish unless specifically approved.

  • Use the least harmful approved method, such as a small scoop net or appropriately operated electrofishing equipment.
  • Keep captured fish in clean, oxygenated water at a suitable temperature and minimise handling time.
  • Do not mix Clarence galaxias with trout or other fish, and do not move any introduced fish into retained habitat.
  • Relocate fish only to nearby suitable retained habitat identified and approved before the work, unless the authority directs another release site.
  • Record the capture location, number, species, sizes, condition, holding time, release location, release time and person responsible.
  • Send injured fish to an approved aquatic veterinarian, wildlife carer or government authority under the project response plan.

During habitat disturbance: Stop-work triggers and records

Stop work in the affected area if a Clarence galaxias is captured, if fish are stranded or injured, or if approved aquatic protection controls fail.

Stop work and seek direction if brown trout, rainbow trout, redfin perch or another introduced fish is detected in or immediately upstream of retained habitat.

  • Stop work for uncontrolled sediment release, fish passage blockage, pump failure, dewatering failure, barrier failure or water quality deterioration.
  • Stop work if the work footprint changes beyond the surveyed and approved area.
  • Protect the location and photograph the event without delaying fish rescue or causing further disturbance.
  • Notify the project environmental officer, aquatic ecologist, relevant regulator and Inland Fisheries Service as required by the approval.
  • Maintain daily records of weather, flow, turbidity, water quality, machinery movements, exclusion-zone inspections, fish observations, captures, releases, incidents and corrective actions.

After habitat disturbance: Completion checks

Do not remove aquatic controls when construction ends. Check that the site has not increased trout access, reduced habitat quality or caused delayed fish mortality.

Complete a post-work aquatic inspection before demobilisation and again after the first substantial flow event or as required by the approval.

Confirm that stream beds, banks, marsh channels, pools, cover, riparian vegetation and fish barriers are stable and functioning.

  • Remove temporary crossings, pumps, cofferdams, spoil and sediment controls only when removal will not damage habitat or release sediment.
  • Check for stranded fish in isolated pools, drains, pits and behind temporary barriers.
  • Verify that culverts, crossings and drainage structures have not created a pathway for trout into Clarence galaxias habitat.
  • Repair erosion, scour, blocked fish passage, bank collapse and damaged riparian vegetation promptly.
  • Keep exclusion fencing and no-go markings in place until the responsible ecologist confirms that the area is safe.

After habitat disturbance: Monitoring and reporting

Monitor affected habitat and any retained population at the frequency required by the approval and species management plan.

Use repeat electrofishing or approved netting surveys to check fish presence, population structure, recruitment and continued isolation from trout.

Recovery monitoring approach: The recovery plan identifies regular electrofishing surveys to assess population size and structure and to confirm isolation from brown trout.

  • Compare post-work results with the pre-work survey using the same reaches, methods and effort where practicable.
  • Inspect for brown trout and rainbow trout during each follow-up survey and report any detection immediately.
  • Record changes in water quality, flow, habitat cover, bank condition, barriers, fish abundance and size classes.
  • Report completion outcomes, incidents, fish handling, monitoring results and corrective actions to the approval authority and relevant Tasmanian database.
  • Apply any required offset, restoration action or additional monitoring specified under the EPBC Act decision or Tasmanian approval.

Rehabilitation actions: Aquatic and riparian restoration

Rehabilitation should restore fish habitat and maintain a permanent barrier to trout access. The target is a stable, connected or appropriately isolated freshwater system that supports Clarence galaxias recruitment.

Reinstate natural stream form, deep pools, shallow margins, marsh channels, undercut banks, rocks and woody cover where these features were disturbed.

Replant disturbed banks with suitable local native riparian vegetation to reduce erosion, shade water and restore cover without blocking approved fish passage.

Habitat types to restore: High altitude lakes, marshes, slow or flowing streams, deep pools and stream margins.

Cover used by adults: The river or lake bed, rocks and other cover.

  • Use local provenance native species suited to the site's high altitude stream, marsh or lagoon environment.
  • Stabilise banks with natural materials and avoid smooth, bare channels that remove cover and slow-water habitat.
  • Remove weeds and prevent sediment, nutrients and chemicals from entering streams and marshes.
  • Do not install structures that connect Clarence galaxias habitat to trout-occupied water unless the design has been assessed and approved.
  • Retain or restore natural fish barriers where they protect populations from brown trout and rainbow trout.

Rehabilitation actions: Threat and predator control

Make trout exclusion and prevention of unauthorised fish introduction a permanent part of the rehabilitation design.

Use approved barrier construction, trout removal, signage and land manager liaison where these actions are required to protect the population.

Known management actions: Barrier construction, trout removal, signage, habitat protection and stocking procedure review are identified recovery actions.

  • Inspect barriers after high flows and repair damage before trout can pass upstream.
  • Remove introduced trout only under an approved fisheries program and never release captured trout into another waterbody.
  • Install warning signs at accessible sites where illegal fish transfer is a foreseeable risk.
  • Manage weeds, feral animals, stock access and fire impacts where they threaten riparian vegetation, banks or water quality.
  • Coordinate maintenance with the Inland Fisheries Service, Parks and Wildlife Service, forestry managers and private landholders where a catchment crosses tenures.

Rehabilitation actions: Success measures

Set rehabilitation completion criteria before works begin and use repeat surveys to test whether they have been met.

Treat the rehabilitation as unsuccessful if trout enter the habitat, fish mortality occurs, habitat remains unstable or Clarence galaxias recruitment declines.

Recovery objective: Protect existing populations, prevent further decline and increase the area of occupancy where feasible.

Genetic consideration: Known isolated populations may be genetically distinct, so translocation or captive breeding decisions should be guided by approved genetic information.

  • Confirm that restored pools, marshes, stream margins and cover remain wet and stable through the relevant low-flow period.
  • Confirm that barriers remain effective and that no brown trout or rainbow trout are detected upstream.
  • Measure riparian recovery, bank stability, turbidity, flow condition, habitat cover and aquatic weed control.
  • Use approved electrofishing or netting surveys to assess Clarence galaxias presence, adult size structure, larvae or juveniles and recruitment.
  • Continue monitoring until the responsible authority accepts that habitat condition, fish security and population performance meet the approved success criteria.
  • Submit final rehabilitation, monitoring and database records to the relevant Tasmanian authority and Commonwealth regulator where required.

Sources