This another article has been taken with permission from the February 2017 Corangamite Lakes Landcare Area Newsletter.
The Yarra Pygmy Perch (YPP) Nannoperca obscura is a small bodied native fish species of south-eastern Australia, typically occurring in slow-flowing water with an abundance of aquatic vegetation. Their diet consists primarily of insects, insect larvae, and crustaceans.
The YPP’s distribution is patchy and highly fragmented. It inhabits southern flowing waterways from Lake Alexandrina in South Australia across to West Gippsland, and has only been identified at 42 locations. Locally, it was most recently found in Gnarkeet Chain of Ponds in 2014 and Woady Yaloak Creek in 2008.
YPP are classified as threatened under Victorian Flora and Fauna Guarantee Act 1998. Nationally, it is listed as vulnerable under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999.
The YPP is under threat and its’ population is highly fragmented across much of its’ historical range due to habitat loss, the impacts of invasive aquatic species, reduced streamflows, and water regulation. The fragmented distribution of its’ remaining habitats and the variability of these habitats between seasons and years, makes the species extremely vulnerable to local extinctions. Reduced flooding and loss of habitat linkages also greatly reduce the ability the YPP to recolonise habitats.
YPP are identified as a key environmental value in the Corangamite Lakes Landcare Area. The Corangamite Catchment Management Authority (CCMA) intends to undertake surveys of local waterways, and in particular the Gnarkeet Chain of Ponds and Woady Yaloak Creek, for the YPP during early 2017 as only minimal surveys have been undertaken in the region in recent years.
While the survey is targeted on the YPP, the survey will also investigate the current status of River Blackfish (Gadospsis marmoratus) in these same catchments. The survey will be undertaken by using electrofishing to temporarily stun the fish, and gathering them with nets. Deeper holes, with more permanent water which provide refuges in dry periods, will be the main locations checked in the survey.
Up-to-date information on the distribution of these species will enable further development and implementation of the CCMA Drought Refuge Management Plan (2010) for native fish species. It will also identify key refuge sites to target riparian and habitat restoration works as part of the CCMA’s ongoing Waterways Frontage Protection and Protecting the Western District Lakes programs.
The survey will be carried out during late February. If you are in the relevant landcare area and interested in the Pygmy Perch and seeing how the survey is done please contact Rod at LLPG on 0458 390 146 for further information, as dates and specific locations are yet to be finalised.