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Fish fact finding mission!

The latest developments in the science and management relevant to the recovery of native fish were presented in Sydney recently as part of the 2015 Murray–Darling Basin Native Fish Forum.

Central Tablelands Local Land Services (LLS) staff were accompanied by nominated representatives from local fishing clubs and councils, including the Wyangala Danglers Fishing Club, Grabine Classic Fishing Competition, Central Acclimatisation Society,  Advisory Council on Recreational Fishing, Carcoar Urban Landcare, Blayney and Upper Lachlan Shire Councils.

"These representatives were selected from an EOI processed based on their involvement in community groups restocking, carp control and riparian restoration projects that support native fish species," said Casey Proctor Central Tablelands LLS.

"The Native Fish Forum was targeting involvement by recreational fishing organisations to share new information and potential ideas for innovative future projects with their community and organisations," said Mr Proctor.

Keynote speaker Martin Mallen-Cooper's presentation on "Does the natural flow paradigm need a rethink?" was well received by both the scientific community and recreational fishers in attendance.

Martin Mallen-Cooper has done work on monitoring both carp and native fish populations in diverse flow conditions, and challenges all water managers and uses to think differently about water delivery in the Murray–Darling Basin. His findings were that fish respond to hydrodynamics – variation in water velocity, depth and turbulence at small (local) and river scales (regional) as well as connectivity and water quality. Suggesting the traditional focus on restoring volumes, discharge and timing is not enough. Thus, the future challenge is to manage for vegetation, floodplain inundation and maintaining hydrodynamic complexity for native fish.

Other presentations promoted new screen technology to avoid harming native fish when operating irrigation pumps, putting a dollar value on maintaining good riparian vegetation cover and condition to minimise erosion damage during high flow events, and the potential release of the Koi Herpes virus for carp control.

"The excitement could be felt by all in the room when NSW DPI Fisheries presented on the recent developments of the Koi Herpes virus for the biological control of carp," commented Mr Proctor. 

Extensive testing of the virus that was first detected in Israel in 1990 has proven that the virus would only effect carp species, with no evidence of replication or to cross contamination.

Much of the work has been done on the virus in other countries that have been trying to eliminate the virus and protect the relevant carp industries!

Case studies show the virus is 70-90% effective based on water conditions, no evidence of effecting human health with examples of people who were working in infected water over 20 years ago not showing any health implications, but a vaccine has been developed as a security measure.

The project is currently obtaining the relative legislative approvals to release the virus, NSW Fisheries are consulting the public, Local Government  and the scientific community to identify and map the associated risks.

The major risks currently identified revolve around carp being 80% of the inland water ways aquatic biomass. The potential cleanup is a real opportunity for community involvement.

"The Cyprinid herpesvirus 3 (CyHV-3) if it's approved, it'll make a massive difference," said Dr Dean Gilligan, a senior research scientist at the NSW DPI Fisheries.

"It's entirely species-specific, it doesn't affect any other animal and it's a really promising candidate for bio-control," he said.

CSIRO scientists in Victoria have been testing the virus for several years, in an exhaustive program to ensure its safety.

Dr Gilligan says the testing is 'time consuming and convoluted - as it should be'.

Assuming approval is granted, scientists say knowing where to release it will be critical for maximum impact as will tracking its progress.

Media contact: Kylie Krause on 0439 608 370