Two Biosecurity Threats Discovered in Auckland Area

Wednesday 23 March 2005

Biosecurity New Zealand has destroyed a number of freshwater marron crayfish and gudgeon fish, following their discovery at a disused service station in West Auckland and at a pond at South Head Kaipara, Biosecurity New Zealand Post-Clearance Animal team manager Ron Thornton said today.

Both the marron (Cherax tenuimanus) and the gudgeon (Gobio gobio) fish are considered to pose a significant threat to native freshwater species and are classified as unwanted organisms under the Biosecurity Act 1993. The Act states that no person shall knowingly communicate, cause to be communicated, release, or cause to be released, or otherwise spread any pest or unwanted organism. Any offence attracts a penalty of up to five years in jail and/or a fine of up to $100,000 for an individual.

"A member of the public came across a lone marron on the footpath outside the West Auckland service station. A property inspection revealed more marron and also gudgeon," Ron Thornton said.

Subsequent investigations revealed a pond at South Head Kaipara containing more specimens of both species.

"Biosecurity New Zealand, in conjunction with the Department of Conservation (DoC), Auckland Regional Council (ARC), and the Ministry of Fisheries, has since eradicated the two species from the pond. The ponds were drained and the gudgeon and marron were destroyed.

"The investigating team is conducting a delimiting survey of ponds in the South Head Kaipara area to establish if there are any further populations.

"Biosecurity New Zealand, in collaboration with the DoC and the ARC, is working to establish if the two pests are widespread and to eradicate them if possible.

"There is a high risk both species could get into our waterways. Gudgeon is particularly likely to have a seriously impact on small native fish.

"The marron may have originated from a marron farm at Warkworth which was closed down in 1993 after DoC expressed concerns about the impact these crayfish could have on native fauna, including the native koura.

All marron on the fish farm at that time were destroyed, but some may have been removed prior to the then Ministry of Agriculture and Fisheries taking over management of the farm.

"The gudgeon are thought to have been smuggled into New Zealand to provide bait for coarse fishing enthusiasts.

"We urge members of the public to notify us on 0800 80 99 66 if they discover any unusual fish or crayfish in ponds in the South Head or Warkworth areas or elsewhere.

"People should contact their local DoC conservancy office for general pest fish issues," Mr Thornton said.

For further information contact Tina Nixon, Communications Adviser on 0-4-498 9948 or 0-27-223 2789

Additional information:

Marron is a freshwater crayfish native to Australia. They are considered to be a delicacy.

Gudgeon are a small "baitfish" popular with coarse fishermen in Great Britain. It is a voracious carnivore.

Coarse fishing is the name given to fishing in still or slow waters for inferior eating fish. The sport is popular with the young and very old as coarse fish are easy to catch with bait such as worms and bread. Many species of coarse fish such as tench, carp and catfish have been in New Zealand for decades but they are all considered to have a negative impact on our natural environment. They must not be removed alive from the pond or waterway where they were caught. DoC has a programme aimed at eradicating coarse fish wherever feasible.



Last Updated: 24 September 2010

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