Tests show Fiordland rivers have escaped didymo spread

00:09, May 16 2012

Anglers, trampers, hunters and other recreational users of Fiordland National Park are doing their bit to control the spread of didymo.

Twenty-two rivers were tested by Fish & Game and the Department of Conservation during summer and they showed no signs of the invasive freshwater pest.

DOC freshwater ranger Lyndsay Murray said this was the third year in a row with no new records of didymo.

"It's a fantastic result and shows that people's willingness to follow the `Clean, Check and Dry' campaign," she said.

"By cleaning, checking and drying their gear, park users continue to help prevent didymo spreading further into the pristine waters of Fiordland."

There was no known way to reverse the spread of didymo once it had established itself in a waterway so preventing it spreading was critical, Ms Murray said.


Most of the rivers selected for monitoring were either popular with anglers or associated with tramping tracks, such as the Clinton and Arthur Rivers along the Milford Track.

Fiordland National Park rivers are threatened by didymo, with many rivers and waterways in the Southland Plains and along the eastern boundary of the park home to the pest.

Te Anau Fish & Game field officer Bill Jarvey said it was vital to continue to prevent the spread and introduction of didymo into Fiordland.

"The bulk of the Southland catchment areas have recordings of didymo including Lake Te Anau and Lake Manapouri which border the park," he said.

"Didymo seems to thrive in lake fed rivers so it's essential users of boats on the lakes don't take the lake up the river."

The Southland Times