Emerald Cling Goby (Stiphodon surrufus)

Conservation status

Queensland, Nature Conservation Act 1992: Endangered.

Identification

The emerald cling goby is a tiny, elongate cling goby found on rock and pebble substrates in flowing rainforest streams. It is difficult to identify reliably without close observation because it is small, shy and often partly transparent.

Adults grow to around 25 mm total length, with some field material reporting a maximum of about 2.3 cm. The body is elongate and cylindrical towards the head, becoming more compressed towards the rear.

The pelvic fins are fused into a disc-like suction structure. This allows the fish to hold onto rocks and boulders in fast-flowing streams, although Wet Tropics cling gobies are often observed on benthic surfaces in no-flow or low-flow areas.

Adult size: Around 2 to 2.5 cm total length

Weight: A few grams

Key feature: Fused pelvic fins forming a disc-like sucker

Identification: Colour and sex

Australian males are brightly coloured, described as orange-red or ruby-red with a blue-green to metallic blue head. Females are smaller, almost transparent and have dull dusky markings.

Colour is most useful when the fish is viewed in clear, shallow water and should be recorded with the habitat and substrate because similar cling gobies occur in the same region.

Male: Bright orange-red to ruby-red body, with a blue-green or metallic blue head

Female: Smaller, almost transparent, with dull dusky markings

Identification: Similar species and field signs

The Wet Tropics contains four Stiphodon cling gobies: emerald, black, orange and opal cling gobies. The emerald cling goby is the smallest described in the supplied material, reaches intermediate elevations and is associated mainly with pebble or rock substrates, but these features should not be used alone for a definitive identification.

No tracks, scats, calls, nests, sloughs or eyeshine are produced. The most useful field sign is a tiny fish clinging to or making short movements across sunlit rock, pebble or cobble surfaces in shallow stream habitat.

• Record photographs of the whole fish, head colour, body colour, fins and substrate where practicable.
• Do not identify a very small cling goby from colour alone when several Stiphodon species occur in the same catchment.
• Treat a suspected emerald cling goby as a potential listed species until identification is confirmed.

Distribution: National range

In Australia, the emerald cling goby is restricted to Queensland’s Wet Tropics. Its Australian range is south of Cairns and is associated with short, steep coastal streams.

The species is recorded in Queensland and has not been reported from another Australian state in the supplied material. The relevant Australian bioregional setting is the Wet Tropics, particularly short coastal catchments south of Cairns.

Outside Australia, it has been reported from Papua New Guinea, West Papua in Indonesia and the Solomon Islands. The broader source material also lists records from other western and central Pacific locations, but the Australian project range is Queensland’s Wet Tropics.

Australian state: Queensland only

Australian bioregion: Wet Tropics

Australian range: South of Cairns

Distribution: Known strongholds and subpopulations

Surveys between 2010 and 2015 found emerald cling gobies in about eight Wet Tropics streams. The four Wet Tropics Stiphodon species were most abundant in the Cape Tribulation subregion, between Ashwell and Noah Creeks, and in the Malbon-Thompson subregion, including Pauls Pocket and Russell Heads Creeks.

Emerald cling gobies were recorded in higher parts of streams than the other Wet Tropics Stiphodon species in the cited survey material. Between 26 and 50 individuals were recorded in Ashwell Creek during the surveys.

Streams recorded in survey material: About 8 streams

Reported local count: 26 to 50 individuals in Ashwell Creek

Population trend: Not established in the supplied material

Total population: Not established in the supplied material

Distribution: Connectivity

The species has a marine larval stage. Adults breed in freshwater, newly hatched larvae are carried downstream and out to sea, and juveniles return to freshwater before moving upstream.

This life cycle means that a local stream population can depend on both the condition of its freshwater reach and access to the estuary, river mouth and nearshore marine environment.

Habitat: Stream habitat

The emerald cling goby occupies clear, flowing freshwater streams in the Wet Tropics, with adults mainly in short, steep coastal catchments. It is associated with rocky streambeds, riparian rainforest conditions and continuous flow.

Preferred habitat consists of freshwater creeks and streams with fast-moving water over rocky bottoms. The species uses bedrock, boulders, cobbles, pebbles and other hard surfaces for attachment and grazing.

In the Wet Tropics, emerald cling gobies were mostly found at intermediate elevation and above at least the first major instream barrier. The supplied material gives a general habitat elevation of 40 to 200 m for the short, steep coastal creeks used by the species.

Stream type: Short, steep coastal rainforest creeks and streams

Substrate: Pebble, rock, cobble, boulder and bedrock surfaces

General elevation: 40 to 200 m

Longitudinal position: Mostly intermediate elevation and above the first major instream barrier

Habitat: Habitat structure and condition

The streambed should retain exposed hard surfaces with shallow riffle and run habitat, stable banks and continuous or near-continuous flow. Riparian vegetation helps maintain stream shading, bank stability and water quality.

For project assessment, inspect both the proposed disturbance area and upstream and downstream reaches. A short work area can affect this species through sediment movement, bank disturbance, altered runoff or loss of passage to the sea.

• Retain riparian vegetation and stable stream banks where practicable.
• Prevent fine sediment, concrete washout, hydrocarbons and other contaminants from entering the channel.
• Maintain natural low-flow and high-flow connections between occupied reaches, estuaries and the sea.
• Check for instream barriers that could restrict upstream juvenile movement.

Foraging habitat: Diet

The emerald cling goby is a benthic grazer that feeds from hard stream surfaces. Its small size and suction disc allow it to remain close to rocks while scraping food from the substrate.

The main diet consists of algae, diatoms and biofilm scraped from bedrock, boulders, cobbles and pebbles. Larvae and juveniles feed on benthic microalgae and zoobenthos, and recruitment success is influenced by the availability of suitable prey.

The supplied material reports occasional benthic invertebrate consumption for some Stiphodon species, but does not confirm the extent of this behaviour specifically for the emerald cling goby.

Adult food: Algae, diatoms and biofilm on hard stream surfaces

Larval and juvenile food: Benthic microalgae and zoobenthos

Foraging method: Scraping food from rock, pebble, cobble and bedrock surfaces

Foraging habitat: Foraging areas

Adults forage on submerged hard surfaces in shallow stream habitat, including areas with low or no surface flow and, at times, shallow areas close to stronger flow. They face into the current when grazing on biofilm.

There is no species-specific home range or foraging distance in the supplied material. For clearing and construction assessments, map the full connected reach containing suitable rocky surfaces rather than treating individual rocks as isolated habitat.

• Inspect shallow riffles, runs, rock margins and low-flow surfaces for grazing fish.
• Record the substrate type, flow condition, water clarity and attached algae or biofilm.
• Avoid disturbing or covering exposed rock and pebble surfaces with sediment or spoil.

Breeding habitat: Breeding biology

Breeding occurs in freshwater, but successful recruitment depends on downstream larval transport to the sea and later upstream return of juveniles. Species-specific reproductive observations are limited, so some details below are based on the expected biology of Stiphodon cling gobies.

Breeding is reported during the wet season. Males clean or defend a suitable stone, court females and guard egg clutches attached to the underside of stones or other hard surfaces. The male remains with the eggs and fans them until hatching.

After hatching, larvae are carried downstream by stream flows and out to sea. They remain in the plankton for several months before returning as juveniles and migrating upstream.

Breeding season: Wet season; exact months are not specified in the supplied material

Clutch size: Not reported for Stiphodon surrufus in the supplied material

Egg placement: On the underside of stones or other hard surfaces, based on Stiphodon observations

Incubation: Eggs are guarded and fanned by the male until hatching; duration is not reported

Pelagic larval duration: Several months; species-specific duration is not reported

Age at maturity: Not reported

Wild lifespan: About 1 to 2 years

Breeding habitat: Breeding habitat and recruitment

Breeding habitat requires clean freshwater, hard stones or other stable surfaces for egg attachment, suitable flow and access to downstream marine waters. The return journey also requires an unobstructed connection from the estuary into upstream habitat.

Flow alteration, sediment deposition, barriers, pollution and works that isolate the stream from the sea can affect eggs, larvae, returning juveniles or the availability of suitable breeding surfaces.

• Inspect the undersides and sheltered faces of stable stones in shallow freshwater habitat during the wet-season breeding period.
• Keep downstream passage open during works and avoid creating temporary or permanent barriers.
• Control sediment and turbid runoff before it enters occupied or potentially occupied stream reaches.

Sheltering habitat: Aquatic refuges

The emerald cling goby does not use terrestrial dens, hollows, burrows or roosts. Its refuge is the submerged streambed, where its flattened pelvic disc allows it to hold position on hard surfaces.

Likely refuge surfaces include the lee side, underside or rough face of pebbles, cobbles, rocks and boulders in shallow streams. The supplied material does not give a species-specific refuge size or a measured shelter distance.

Low-flow benthic areas are important because Wet Tropics Stiphodon gobies were mostly observed in areas with no surface flow or low flow, while the suction disc also allows them to withstand faster water when required.

Terrestrial shelter: None reported; this is a fully aquatic species

Known refuge substrate: Pebbles, rocks, cobbles, boulders and bedrock

Refuge size: Not reported

• Retain natural rock, pebble and cobble cover in the channel.
• Do not place machinery, spoil, temporary crossings or cofferdams over occupied rocky habitat without an approved species management response.
• Inspect shaded and sunlit rocks, substrate edges and low-flow margins because the fish can be cryptic and almost transparent, especially females.

Threats: Hydrology and connectivity

The main project risks are loss of continuous streamflow, sediment and water-quality degradation, riparian disturbance, instream barriers and interruption of the freshwater to marine life cycle. The Queensland risk assessment identifies several threats as high or very high for upland cling goby species, including the emerald cling goby.

Changes in rainfall, runoff and flow regimes were assessed as a very high risk for upland cling goby species. Water extraction, damming, altered hydrology and impoundment can reduce the continuous flow and rocky habitat needed by cling gobies.

Instream barriers restrict the longitudinal distribution of the species and can prevent returning juveniles from reaching suitable upstream habitat. Because larvae move to the sea, barriers and works near the lower stream also need to be assessed for effects on downstream and upstream passage.

• Maintain natural flow paths and avoid dewatering occupied reaches.
• Provide fish passage around temporary and permanent instream structures.
• Assess culverts, crossings, weirs and erosion-control structures for passage of very small upstream-migrating juveniles.
• Protect the connection between occupied freshwater habitat, the estuary and the sea.

Threats: Clearing, sediment and water quality

Riparian vegetation clearing or degradation, aquatic habitat degradation and water-quality degradation can remove stable rocky habitat, increase sediment loads, reduce bank stability and alter stream shading and flow conditions.

Fine sediment can cover the rock and pebble surfaces used for feeding, sheltering and egg attachment. Toxicants, suspended sediments and nutrients were identified as relevant threats to cling gobies.

• Use sediment and erosion controls suited to steep, high-rainfall catchments.
• Keep cleared soil, spoil, concrete washout, fuels and chemicals out of the drainage line.
• Retain riparian vegetation and avoid unnecessary bank and bed disturbance.
• Inspect downstream areas after rainfall and construction events for deposited sediment and altered channel form.

Threats: Climate, extreme events and invasive species

Rising temperatures were assessed as a high risk for upland cling goby species. Heatwaves, extreme rainfall, cyclones and floods, landslides, drought and changing flow regimes can damage or remove stream habitat.

Invasive terrestrial animals and livestock were assessed as a very high risk, while invasive fish and translocated native fish were assessed as moderate risks. Predatory or competing fish can alter the small native fish assemblage in occupied streams.

• Keep livestock and other large terrestrial animals out of occupied stream reaches where practicable.
• Do not move fish, water, sediment or aquatic equipment between catchments without appropriate hygiene controls.
• Inspect for landslide debris, channel scour, blocked passages and loss of rocky substrate after extreme rainfall.
• Include climate-related low-flow, heat and flood effects in the project risk assessment.

Threats: Collection and human disturbance

The species is listed as no take under the Queensland Fisheries Act as a cling goby. Illegal collection for aquariums may occur, and visitor use and modification of riparian and instream areas were assessed as a moderate risk for upland cling gobies.

Direct handling can damage very small fish and disturb eggs or biofilm-covered substrates. Fish surveys should use the least damaging method that can meet the project objective and should be carried out by appropriately authorised personnel.

• Prevent unauthorised collection or aquarium removal from project waterways.
• Limit trampling, rock turning and repeated access through shallow riffles.
• Keep survey and construction personnel, pets and vehicles out of occupied streambeds unless access is approved and controlled.

Survey methodology: 1. Map and inspect stream habitat

Survey the Emerald Cling Goby in shallow, clear freshwater streams and creeks, with attention to fast-flowing rocky reaches and upstream connectivity. The species is very small and can be overlooked, so use careful in-water observation and record habitat conditions as well as detections.

Before fieldwork, map short, steep coastal streams, riffles, rocky reaches, stream crossings, barriers and the full area that could be affected by the project.

Give particular attention to reaches at about 40 to 200 m elevation and to habitat above the first major instream barrier, where Emerald Cling Gobies are commonly found in the Wet Tropics.

Inspect shallow water to about 3 m depth where safe, including pebble, cobble, rock and bedrock surfaces with algae or biofilm.

Typical Australian habitat: Short, steep coastal streams and creeks in the Wet Tropics south of Cairns

Elevation reported for Australian habitat: About 40 to 200 m

Reported depth range: 0 to 3 m

Australian stream records in survey data: About 8 streams

• Walk the stream margins and accessible channel before disturbing the bed, banks, riparian vegetation or flow.
• Record stream name, catchment, coordinates, elevation, reach length inspected, water depth, flow, substrate, water clarity, barriers, shade, sediment and visible aquatic weeds.
• Treat connected downstream habitat and the route to the estuary or ocean as part of the survey area because the species has an amphidromous life cycle.

Survey methodology: 2. Careful visual and snorkel searches

Use careful creek walking, shallow-water observation and snorkelling where conditions are safe and the method is authorised for the site.

Move slowly and inspect sunlit stones, pebbles, rocks and bedrock for a small fish clinging to the surface with its fused pelvic suction disc.

Search low-flow and no-surface-flow areas as well as shallow riffles, because Wet Tropics Stiphodon species are benthic and may not be visible in the strongest current.

Look for males with bright orange-red or ruby-red bodies and blue-green heads, and females that are very small, pale or almost transparent.

Adult size: Around 2 to 2.5 cm total length

Key identification feature: Fused pelvic fins forming a disc used to cling to rocks

Male colour: Bright orange-red or ruby-red body with a blue-green head

Female appearance: Much smaller and almost transparent

• Use an experienced aquatic surveyor who can distinguish Emerald Cling Gobies from other Stiphodon species and small stream fishes.
• Avoid turning or removing rocks unless this is necessary, authorised and covered by the project fauna management plan.
• Record each observation with a photograph where possible, but do not delay release or expose fish to air unnecessarily.
• Record non-detections with the search conditions and effort because the species can be rare and inconspicuous.

Survey methodology: 3. Survey timing and conditions

Prioritise surveys when the stream is flowing and water clarity allows the bed and rock surfaces to be inspected safely.

Include wet-season conditions in the survey plan because breeding occurs in the wet season and newly hatched larvae are carried downstream by strong flows.

Avoid relying on a single survey immediately after extreme rainfall, flooding or sediment disturbance, when visibility and fish distribution may be atypical.

Where works may affect flow, barriers or the stream bed, inspect both upstream and downstream reaches and assess the route used by returning juveniles.

Breeding period reported: Wet season

Larval period: Larvae hatch in freshwater, drift to sea and return as juveniles

Pelagic larval duration: Comparable Stiphodon species have reported averages of about 66 to 73 days; a species-specific value for Emerald Cling Goby was not provided

• Repeat the inspection if the first visit is during high turbidity, unsafe flow, a dry reach or another condition that prevents reliable observation.
• Record rainfall, recent flood conditions, flow, turbidity, water temperature if measured, and the time and date of each search.
• Plan additional assessment where a project could affect downstream larval transport or upstream juvenile migration.

Survey methodology: Minimum effort and reporting

No species-specific survey effort, such as a required number of nights, trap nights, hours or transect length, is provided in the supplied documents.

Set effort in the project fauna management plan to cover every potentially affected stream reach and repeat searches when conditions prevent reliable detection.

• Use only methods approved for the relevant state, catchment and project approval, and obtain any required aquatic fauna or fisheries permissions before sampling.
• Submit verified records to the relevant state wildlife database and Queensland biodiversity or fisheries recording system where applicable.
• Report coordinates, date, observers, method, search area or reach length, conditions, photographs, identification confidence, abundance estimate and any handling or relocation.
• Record threatened status separately from the survey result: the species is listed as Endangered under Queensland legislation and is not listed under the EPBC Act in the supplied information.

Before habitat disturbance: Avoid and minimise habitat loss

Avoid direct disturbance to the small, connected stream habitats used by the Emerald Cling Goby. The main planning focus is to retain continuous flow, rocky bed habitat, riparian cover and access between the sea and upstream reaches.

Avoid works in short, steep coastal streams and in rocky reaches supporting algae or biofilm.

Retain continuous streamflow, natural bed and bank form, riparian vegetation, shade and pebble, cobble, rock and bedrock surfaces.

Avoid creating or retaining instream barriers that could restrict upstream movement of returning juveniles.

Keep works outside the channel wherever practicable and use existing crossings or previously disturbed areas.

• Do not set a generic buffer distance for this species unless it is specified by the approval or project aquatic ecology assessment, because the supplied documents do not provide a species-specific distance.
• Include upstream and downstream effects, not only the footprint, when assessing flow alteration, sediment movement, barriers, water quality and access to the estuary or ocean.
• Design drainage and erosion controls so that sediment, nutrients, toxicants and turbid water do not enter occupied or connected habitat.

Before habitat disturbance: Check approvals and plan the works

Check the current Queensland threatened species and fisheries requirements before works begin because the Emerald Cling Goby is Queensland Endangered and is a no-take species under the Queensland Fisheries Act.

The supplied information states that the species is not listed under the EPBC Act, but assess the project for other protected matters and refer it if another EPBC trigger applies.

Prepare a fauna management plan covering aquatic surveys, fish handling, water quality, flow protection, sediment control, incident response, records and stop-work authority.

• Confirm whether permits are required for capture, handling, release, relocation, electrofishing, construction in water or disturbance of a no-take species.
• Schedule in-channel works to avoid the wet-season breeding period where practicable, and seek advice if timing cannot avoid it.
• Stage works so that flowing habitat and a safe fish passage route remain available at every stage.
• Have an aquatic ecologist or other appropriately authorised person approve any proposed fish rescue or relocation method.

Before habitat disturbance: Prepare the site

Complete the pre-clearance aquatic survey before removing riparian vegetation, altering banks, entering the channel, diverting water or placing material in the stream.

Mark retained stream reaches, rocky bed habitat, riparian exclusion areas, access routes, no-go areas and approved machinery crossing points.

Install exclusion fencing, sediment controls and clean water diversions where these measures can be used without blocking fish passage or causing bank damage.

• Brief all workers and operators on the species, its small size, its suction-disc behaviour, the no-take requirement and the project stop-work procedure.
• Inspect machinery, pumps, hoses and footwear before entering the catchment to reduce transfer of sediment, weeds, fish and pathogens.
• Provide a clean, shaded and secure location for any authorised temporary holding equipment before aquatic works commence.

During habitat disturbance: Daily controls and machinery coordination

Treat any in-channel work as a live aquatic fauna risk. The fauna spotter catcher must have clear authority to stop machinery, control the work area and arrange authorised aquatic fauna management.

Complete a daily inspection before machinery enters or approaches the channel, including a check for fish, flow, turbidity, sediment controls, barriers and changed water levels.

Maintain a clear exclusion zone around the active channel and retained rocky habitat, with the distance set by the approved method and site conditions.

Use a spotter who remains in direct communication with the operator and can stop the activity immediately if an animal, unsafe flow or control failure is detected.

• Move machinery slowly near water and do not drive through occupied habitat unless the approved method specifically permits it.
• Keep fuels, concrete, spoil, wash water, litter and other contaminants away from the channel.
• Stop work if sediment controls fail, a discharge occurs, fish passage is blocked, flow is substantially reduced, or water becomes too turbid for the approved fauna method.
• Do not pump, divert or dewater a reach until an authorised aquatic fauna search and rescue procedure has been completed.

During habitat disturbance: Handling and response to a find

If an Emerald Cling Goby is found, stop the activity that could affect it and keep machinery, people and materials out of the immediate waterway area.

Do not collect, retain, transport or relocate the fish unless the person and method are authorised under the approval and relevant Queensland requirements.

If relocation is approved, release the fish into nearby retained, flowing and suitable habitat selected by the aquatic ecologist, while maintaining the connection needed for the species' life cycle.

Send injured fish to an appropriately qualified aquatic veterinarian, wildlife carer or other authorised facility, following the project fauna management plan.

• Use clean, suitable equipment and minimise handling, air exposure, crowding, temperature change and time out of water.
• Do not rely on a general terrestrial fauna spotter catcher licence for aquatic fish handling; confirm the person's aquatic authorisation before work starts.
• Record the location, time, condition, identification, number of fish, method, handler, destination and outcome for every detection or handling event.
• Notify the project environmental officer and regulator when a threatened fish is injured, killed, unlawfully collected or found outside the approved impact area.

During habitat disturbance: Protect the stream bed and flow

Retain rocks, pebbles, cobbles and bedrock that provide attachment surfaces and grazing areas for the goby.

Prevent sediment smothering, toxicant entry, nutrient pollution, dewatering and uncontrolled changes to flow.

Keep temporary crossings, cofferdams, pipes and diversions from preventing upstream or downstream movement.

Inspect downstream reaches after rainfall or construction incidents for sediment, stranded fish, changed flow and new barriers.

• Treat a new barrier, stranded fish, unexpected aggregation, major sediment release, fish kill or loss of flow as a stop-work trigger.
• Do not remove rocks or simplify the channel unless the action is specifically approved and aquatic fauna controls are in place.
• Maintain a downstream release flow during staged works where required by the approval and aquatic assessment.

After habitat disturbance: Post-clearance checks

Leave the stream connected, flowing and suitable for grazing and attachment after each work stage. Verify that controls worked before demobilising and continue checks for delayed sediment, flow and fish passage impacts.

Complete an aquatic fauna inspection after channel works, dewatering, bank works, crossing removal or reinstatement.

Check retained and downstream habitat for live fish, stranded animals, injured animals, sediment deposition, changed bed structure, altered flow and blocked passage.

Remove temporary barriers, pumps, hoses, spoil and waste as soon as they are no longer needed, without disturbing fish or the bed.

• Repeat the inspection after the first substantial rainfall or flow event following works.
• Repair failed erosion, sediment and exclusion controls promptly.
• Record whether rocks, bed materials, riparian shade, flow and access between upstream habitat and the estuary remain available.

After habitat disturbance: Monitoring and reporting

Monitor the affected reach and connected habitat at the frequency required by the approval, fauna management plan or aquatic ecology assessment.

Use the same reach boundaries, observation method and habitat measurements at each visit so that changes in detection and habitat condition can be compared.

Report all Emerald Cling Goby records, mortalities, rescues, relocations, incidents, control failures and corrective actions to the project environmental officer and relevant regulator.

• Submit verified species records to the relevant state wildlife database and Queensland biodiversity or fisheries database where applicable.
• Keep photographs, field sheets, coordinates, water conditions, search effort, authorisations and chain-of-custody information with the project environmental records.
• Escalate repeated non-detection after habitat damage, reduced flow, new barriers or poor water quality for ecological review rather than treating it as evidence that the species is absent.

After habitat disturbance: Maintain controls and offsets

Maintain riparian protection, sediment controls, fish passage and flow requirements until the site is stable and the approval allows their removal.

Apply any required offset, rehabilitation or compensatory action in accordance with the approval and Queensland threatened species requirements.

Review the design if monitoring shows that the project has reduced stream connectivity, rocky substrate, water quality or recruitment access.

• Do not use an offset as a substitute for avoiding direct damage to occupied stream habitat.
• Document the final area of habitat retained, disturbed, restored or protected and the condition of each reach.
• Continue management for invasive fish, invasive animals, weeds, livestock access and unauthorised collection where these risks are identified.

Rehabilitation actions: Reinstate stream habitat

Rehabilitation should recreate a cool, connected, flowing stream with stable rocky surfaces and intact riparian cover. The aim is to restore the physical and biological conditions used for attachment, grazing, breeding and movement.

Reinstate natural channel shape, bed levels, riffle and pool sequences, stable banks and continuous flow rather than leaving a simplified or impounded channel.

Replace suitable native rock, pebble and cobble substrate where it was removed, using a design approved by the aquatic ecologist and regulator.

Re-establish shaded riparian vegetation that stabilises banks, limits heating and supplies organic matter without obstructing fish passage.

• Do not place loose material where it can move downstream and create a barrier or smother occupied habitat.
• Design crossings, culverts and temporary structures to retain upstream and downstream passage for returning juveniles and access to the sea.
• Use local native plant species and site-appropriate riparian communities specified by the rehabilitation ecologist or approval.

Rehabilitation actions: Manage threats during recovery

Control sediment, weeds, livestock access, invasive terrestrial animals, invasive fish and translocated native fish where they threaten the rehabilitated reach.

Maintain erosion and sediment controls until banks and ground cover are stable through the relevant flow conditions.

Prevent unauthorised collection because Emerald Cling Gobies are a Queensland no-take species and illegal aquarium collection is a documented risk for cling gobies.

• Inspect after storms, extreme rainfall and floods for landslides, bed scour, new barriers, blocked passage and loss of flow.
• Do not introduce fish, move native fish between catchments or stock the rehabilitated stream.
• Use fire and vegetation management practices that protect riparian shade, bank stability and perennial streamflow.

Rehabilitation actions: Measure success

Set success measures around stable flowing habitat, retained or restored rocky substrate, effective fish passage, acceptable water quality and recovery of riparian cover.

Repeat standardised visual or snorkel searches in the rehabilitated reach and connected upstream and downstream reaches under suitable flowing and clear conditions.

Compare detections, habitat condition, turbidity, substrate, flow and barriers with the pre-works baseline.

Relevant biological process: Adults breed in freshwater, larvae drift to sea, and juveniles return upstream

Habitat feature to monitor: Pebble, rock and bedrock surfaces with algae or biofilm

Key restoration outcome: Connected, flowing, rocky stream habitat without new barriers

• Treat failure to restore flow, passage, rocky attachment surfaces or water quality as a requirement for corrective action.
• Continue monitoring through wet-season flow events because breeding and downstream larval transport are linked to seasonal flows.
• Report monitoring results and any Emerald Cling Goby records to the project environmental officer, approval authority and relevant state database.

Sources

• Emerald Cling Goby - Stiphodon surrufus, marinewise.com.au: https://marinewise.com.au/fish-species/emerald-cling-goby/
• [PDF] Threats, risk assessment and recovery action planning for rare and ..., Queensland Government: https://era.dpi.qld.gov.au/id/eprint/15230/1/Wet-Tropics-fish-risks-and-recovery-actions_QG_2025.pdf