R. Wager and P. Jackson
Environment Australia, June 1993
ISBN 0 6421 6818 0
Species recovery outline: Clarence Galaxias
Scientific name: Galaxias johnstoni
English names: Clarence Galaxias
Species taxonomic status: Formally described by Scott, 1936.
Species survival status: Distribution severely reduced through interaction with introduced brown trout (Salmo trutta).
- Action plan status: Endangered.
- Australian Society for Fish Biology status: Endangered.
- Proposed new IUCN criteria status: Critical (interaction with introduced species).
Former distribution: The Clarence Galaxias occurred in the Derwent River Drainage (south east Tasmania) possibly throughout the Clarence River and nearby tributaries. Recently known only from the Clarence Lagoon and its tributaries.
Current distribution: The following populations are currently known:
- The headwaters of the Clarence River including an unnamed lagoon, Clarence Lagoon, tributaries of Clarence Lagoon and the Upper Clarence River immediately below Clarence Lagoon.
- The headwaters of Dyes Rivulet and Dyes Marsh.
- An unnamed lagoon in the Wentworth Hills.
Habitat: Inhabits the rocky margins of streams and lagoons. It only occurs in streams in remote locations which don't contain brown trout. It does co-exist with brook trout in Clarence Lagoon.
Reasons for decline: Interaction with introduced brown trout.
Conservation reserves on which species occurs: Wentworth Hills has been nominated as a Forestry Commission Wildlife Priority Area. Clarence Lagoon and its catchment are included in the Tasmanian Wilderness World Heritage Area. Clarence Lagoon also has interim listing on the register of the National Estate as part of the Clarence Lagoon-Wild Dog extension area.
Other public lands on which species occurs: Dyes Rivulet and Dyes Marsh (State Forest).
Other land on which species occurs: Dyes Rivulet (private grazing land).
Is knowledge about species adequate for objectives and actions to be defined accurately? (If not provide list of additional studies required): Yes.
- To maintain or increase current range and size of existing populations.
- Identify other populations.
- Translocation of populations or restocking within the known range.
- Monitor known populations for changes in numbers or presence of brown trout.
Management actions already initiated:
- Conservation reserves proposed for Clarence Lagoon area and Wentworth Hills. See above.
- Surveys of the Clarence River drainage identified additional populations at:
- An unnamed lagoon upstream of Clarence Lagoon;
- Dyes Marsh and the headwaters of Dyes Rivulet;
- An unnamed lagoon in the Wentworth Hills.
- A small stream that flows into the Nive River, south east of Wentworth Hills, was identified as suitable for stocking with Clarence Galaxias. This stream is permanent, free of brown trout and accessible for monitoring.
Management actions required:
- Declaration of additional conservation reserves:
- Ensure that proposed conservation reserves proceed.
- Additional reserves may be required to protect re-established or translocated populations.
- Habitat management:
- Continue stocking of brook trout (Salmo salar) in preference to brown trout in Clarence Lagoon.
- Maintain the trout free status of Wentworth Lagoon. If brown trout are illegally stocked then they should be removed.
- Monitor the Dyes Rivulet population. If environmental conditions change and lead to increased water in the drainage consider developing a brook trout fishery and excluding brown trout.
- Feral animal control: See habitat management.
- Continue the stocking of brook trout in preference to brown trout in the Clarence Lagoon area.
- Translocation or re-establishment of populations: A population should be established in a tributary of the Nive River to the south east of Wentworth Hills. This stream, although outside the Clarence River drainage, is permanent, free of trout, and able to be monitored.
- Captive breeding: Not currently required.
- Other: Yes.
- Development of road access to the Wentworth Hills area should be discouraged. Limiting access will decrease the likelihood of an illegal introduction of brown trout.
- Due to the seasonal cessation of flow and the proximity of brown trout populations, management options for the Dyes Rivulet population are limited. It is recommended that the population not be subject to any special management at this stage. If any development in the area results in increased flow volumes then a brook trout fishery should be established and brown trout excluded.
Organisations responsible for conservation of species:
- Inland Fisheries Commission.
Other organisations or individuals involved:
- Forestry Commission.
- Department of Environment and Land Management.
Can recovery plan be carried out with existing resources?: No.
- Cost of annual monitoring of this species would be included in an annual program to monitor Swan Galaxias, Clarence Galaxias, swamp galaxias, Saddled Galaxias and Dwarf Galaxias (see Swan Galaxias for details). Annual funding required for monitoring of this species would be $2 440.
Annual monitoring $2 440