MEDIA RELEASE

6 December 2007

Didymo found in Rangitata Diversion Race

Salmon and trout anglers have been asked to be extra vigilant after the invasive algae didymo was yesterday confirmed in the Rangitata Diversion Race. Fish & Game New Zealand announced today.

The Rangitata Diversion Race discharges water into the Ashburton, Hinds and Rakaia Rivers. “These rivers were previously considered free of didymo” said Fish & Game Environment Officer Jason Holland, “but as a result of RDR discharges, it is virtually assured that didymo will now infect these rivers too.”

Fish & Game also expressed disappointment at MAF’s ongoing willingness to grant permits to irrigation companies to transport didymo. “Currently, large irrigation schemes discharge water directly to other rivers. Additionally, some district council stock water schemes transfer water between waterways. MAF could require irrigation companies to investigate and implement better alternatives. For instance, Fish & Game have suggested that for smaller discharges, discharging to ground via soakpits would be an effective barrier to didymo spread. For larger discharges, we have suggested the irrigation company should commission scientific studies to determine what alternatives may be available. To date none of our suggestions have been adopted by MAF.”

Notwithstanding this concern, Mr Holland considers that the increased likelihood of didymo infecting rivers such as the Rakaia is even more reason for anglers to check, clean and dry their gear. “The Rangitata Diversion Race discharges into the Rakaia River via the Highbank Power Station, which is in the middle reaches of the river. Our main priority now is stop didymo moving upriver into the critically important headwater salmon spawning streams. If didymo infects those streams, the sustainability of our sportsfisheries may be gravely endangered.”

Fishing for trout or salmon has already been banned in many Rakaia and Rangitata spawning streams to minimise the risk of didymo spread. Waters that have been closed to fishing are signposted and are also listed in regulation booklets issued when purchasing sportsfishing licences. For the Rakaia these include Double Hill Stream, Glenariffe Stream, Hydra Waters, Manuka Point Stream and Winding Creek and Deep Stream and Deep Creek in the Rangitata. Fishing in the Highbank tailrace itself is also closed to sportsfishing.

“We ask all anglers to be extremely vigilant about checking, cleaning and drying their gear when fishing the Rakaia, Ashburton or Hinds Rivers. This includes following the same procedure if _moving[g1] [g2] considerable distances up the same river during a fishing expedition.”

ENDS

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