The Action Plan for Australian freshwater fishes
Species recovery outline: Ewen's Pygmy Perch
Scientific name: Nannoperca variegata
English names: Ewen's Pygmy Perch, Variegated Pygmy Perch
Species taxonomic status: Formally described by Kuiter and Allen, 1986.
Species survival status:
- Action plan status: Vulnerable.
- Australian Society for Fish Biology status: Vulnerable.
- Proposed new IUCN criteria status: Vulnerable (altered habitat, interaction with introduced species).
Former distribution: Unknown. Species only described in 1986.
Current distribution: Only known from Ewen's Ponds near Mount Gambier, South Australia and from the Glenelg River drainage near Winnap, western Victoria.
Habitat: Prefers clear, flowing streams or ponds with abundant aquatic vegetation.
Reasons for decline: Populations in South Australia are not considered to have declined in abundance or range over last decade. Factors responsible for a decline of Victorian populations not well known.
- Most probable cause of decline likely to be generalised destruction of habitat including removal of aquatic and riparian vegetation and drainage of swamps.
- Interactions with introduced species may also be implicated in the decline:
- Aggression (fin-nipping, harassment) and predation of juveniles by gambusia (Gambusia holbrooki).
- Predation by redfin (Perca fluviatilis), brown trout (Salmo trutta) or rainbow trout (Oncorhynchus mykiss) is possible.
- Habitat destruction possibly through large populations of carp (Cyprinus carpio) destroying aquatic vegetation.
Conservation reserves on which species occurs: Ewen's Ponds Conservation Park (SA).
Other public lands on which species occurs: None.
Other land on which species occurs: Private land.
Is knowledge about species adequate for objectives and actions to be defined accurately? (If not provide list of additional studies required): No.
- Determine habitat requirements.
- Investigate potential threatening processes.
- Identify reproduction requirements.
- Protect existing populations and habitat.
- Establish new populations in suitable habitat.
Management actions already initiated:
- Listed under schedule two of the Flora and Fauna Guarantee Act.
- Preparation of a Recovery Plan outlining management proposals is being prepared with funding from the ANPWS Endangered Species Program.
Management actions required:
- Declaration of additional conservation reserves: Yes.
- Habitat management: Yes.
- Protection of Glenelg River drainage population habitats.
- Feral animal control: Yes.
- Investigation and control of introduced brown trout in Ewen's Ponds.
Investigation of introduced species including translocated golden perch populations in Glenelg River drainage.
- Translocation or re-establishment of populations: No.
- Captive breeding: Yes.
- Develop techniques for captive breeding.
- Other: No.
Organisations responsible for conservation of species:
- Department of Conservation and Natural Resources, Victoria.
- Department of Fisheries, South Australia.
- Department of Lands, South Australia.
Other organisations or individuals involved:
- Rudi Kuiter.
Can recovery plan be carried out with existing resources?: No.
- A joint Yarra and Ewen's pygmy perch study team is proposed. See Yarra pygmy perch for details.
- Australian Grayling may occur in Ewen's Ponds Conservation Reserve.