Redfin perch survey in Plenty River
The Salmon Ponds has been run as a hatchery and fish rearing facility for 150 years. Whilst visitation is now the primary role of the historic site, the facility does continue to hatch and rear trout on a small scale for stocking of waters around the state.
In the late 1980’s a Derwent pump and pipeline was installed to enhance water flow and improve water quality to ensure fish welfare at the Salmon Ponds. This has increased the risk of contamination of redfin perch entering the Salmon Ponds grounds and contaminating the Plenty River, compromising the operations and biosecurity of the hatchery and holding facility.
Although no redfin perch were discovered within the display ponds this year whilst conducting routine cleaning and maintenance, previously, individual redfin perch have been sighted so IFS undertook a bio-security assessment this past summer.
Rigid sampling was undertaken to track any possible redfin perch translocation. Using backpack electrofishing and capitalising on the skills and experience of the IFS Carp Management Team a three hour electrofishing survey was taken over 1.8 km reach.
Two backpack electro fishers and three staff, Chris Bowen, Brock Cuthbertson and Brett Mawbey, systematically worked the stream targeting all habitat types in search of redfin perch. They started at the bottom weir (historic fish ladder site) adjacent to Redlands homestead and finished at the top weir above the Salmon Ponds.
The great outcome was that no redfin perch were observed or captured.
Moving forward to ensure this remains the case we will
• Isolate tanks holding fish that will be transferred from the Salmon Ponds
• Screen outlets during the annual ponds cleaning and maintenance
• Remain visually vigilant.
• Sample the Plenty River next Summer following the same protocol