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Aussie Rivers Under Threat From Nz 'rock Snot'


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Aussie rivers under threat from NZ 'rock snot'

AUSTRALIA'S alpine waterways will be choked with "rock snot" if its lackadaisical biosecurity approach to the highly invasive alga is not drastically improved, a fishing group says.

The alga didymo, commonly known as "rock snot", can form massive smothering blooms on the bottom of streams, rivers and lakes, as it has in New Zealand since 2004.

People in New Zealand are legally obliged to prevent its spread by drying and cleaning gear when moving from one waterway to another.

Didymo expert Cathy Kilroy today warned Australian authorities at a Hobart conference there is a "real risk" it will be introduced inadvertently by fishermen, bushwalkers or kayakers returning from New Zealand.

"Any equipment that has been used in freshwater has the potential to carry the alga, particularly larger recreational equipment such as kayaks, rafts and paddles."

Dr Kilroy said "rock snot" can be spread by a single drop of water.

Anglers Alliance Tasmania executive officer Richard Dax today said the 30,000 anglers his group represented were "absolutely concerned" about the threat.

Mr Dax said the Australian Quarantine Inspection Service (AQIS) approach to rock snot was lackadaisical.

"Much more drastically needs to be done at airports and ports. It's not coordinated and it's not seen as being serious enough," Mr Dax told AAP.

"The bottom line is that once it gets in here there's no way to control it.

"It will run rampant, particularly in Tasmania, because it loves cold water that runs fast."

Mr Dax said AQIS did not scrutinise bushwalkers and kayakers as much as it should, concentrating instead on fishermen.

Anglers also criticise the ad-hoc, spasmodic Australian decontamination process. In Australia it can take days for gear to be returned when all gear in New Zealand is decontaminated in about 10 minutes, Mr Dax said.

"Australian biosecurity officers are not doing nearly enough at points of entry," he said.

The conference was told today didymo also poses a devastating threat to hydro-electric and agricultural industries.

The head of biosecurity in Tasmania's Department of Primary Industry and Water, Alex Schaap, downplayed the fishermen's criticisms.

"Anglers are a high-risk pathway but bushwalkers boots are of interest to quarantine officers for various reasons, so I don't think it's fair to say they are not getting reasonable attention," he told AAP.

"And my understanding is that the import requirements for didymo are being reviewed and that includes looking at different treatment options.

"But it's fair to say that whatever we do there will be an inconvenience to anglers, bushwalkers and others returning from New Zealand."

Comment was being sought from AQIS.


News Release from the Tasmanian Department of Primary Industries and Water

Tasmania Leading The Way On Rock Snot

A leading New Zealand expert on the freshwater pest alga, didymo (Didymosphenia geminata), commonly known as Rock Snot, today commended the pro-active approach taken by the State to prevent the introduction of this invasive quarantine pest to Tasmania.

Dr Cathy Kilroy, from New Zealand’s National Institute for Water and Atmospheric Research, who was the guest speaker at a Didymo Prevention Forum held in Hobart today, praised the initiative shown by the various authorities, but warned that Tasmania was susceptible to a didymo invasion.

Rock snot, which is native to the Northern Hemisphere, was discovered in New Zealand in 2004, and has spread extensively on the South Island, causing significant problems for New Zealand fisheries and biosecurity with the risk of it spreading to the North Island.

Dr Kilroy identified Tasmania, like New Zealand’s South Island, as being particularly susceptible to a didymo invasion due to the State’s popularity as an international trout fishing destination coupled with a suitable habitat for the alga.

“There is a real risk of didymo being introduced inadvertently by travelling anglers in used fishing gear, which is the most likely way it was introduced in New Zealand,” said Dr Kilroy.

“However, any equipment that has been used in freshwater has the potential to carry the algae, particularly larger recreational equipment such as kayaks, rafts and paddles.

“It takes just one didymo cell to start a population and cells can survive for long periods in a moist environment or just a single drop of water.

“Under the right conditions, didymo cells can multiply rapidly, forming blooms that smother the stream or lake-bed.

“These blooms may adversely affect water quality, ecology and fish stocks, and become a hazard for hydro-electric generation, irrigation and recreational pursuits,” Dr Kilroy said.

The head of Biosecurity in Tasmania’s Department of Primary Industry and Water, Alex Schaap, echoed Dr Kilroy’s concern for the potential risk of a didymo invasion and explained the action taken by the Federal Government to increase the quarantine restrictions on the importation of used fishing and other freshwater recreational equipment.

“All used freshwater sports equipment must be declared upon arrival in the country,” said Mr Schaap.

“Any potentially contaminated gear will be confiscated by quarantine staff and treated at the traveller's expense.

“This is vital as Australia’s first-line defence in preventing the introduction of pests such as didymo.

“The Tasmanian government has been actively encouraging this defence at a national level, along with implementing its own didymo awareness campaign, and is now preparing further defence strategies.

“This action is timely given that Tasmania is set to host the 2009 Whitewater World Cup Kayaking Championships, which will see about 250 kayakers from all around the world arriving with kayaking equipment.

“Today’s Didymo Prevention Forum, which brings together key organizations responsible for natural resource management in Tasmania, will assist the development of strategies to prevent the spread of didymo.

“Dr Kilroy has been invited from New Zealand to provide expert advice on didymo and share the lessons learnt for management,” Mr Schaap said.

Dr Kilroy will lead a practical workshop to demonstrate sampling procedures, micro and macro-scopic identification and discuss monitoring and surveillance strategies, which will assist in the development of a Surveillance and Response Plan.

Mr John Diggle, Director of Inland Fisheries, said that anglers had been extremely supportive of the campaign against didymo and were keen to see actions that would protect Tasmania’s trout fishery, which is considered world class.

“Advertising in fishing magazines, display posters at entry points to the State and at fishing events, as well as an information brochure, have been successful in raising awareness amongst anglers,” Mr Diggle said.

“It’s critical that anglers and other recreational freshwater users are responsible with their gear to help reduce the risk of didymo.

“Apart from the quarantine requirements, the campaign encourages anglers to Check, Clean, Dry their gear as a matter of habit before travelling between waterways.

“The New Zealand experience shows only too clearly that prevention is better than cure.

“The cooperative approach shown today will strengthen our efforts to keep Tasmanian waterways free of didymo,” Mr Diggle said.

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