Surveillance saves lake from purple peril
Two years ago Lake Papaitonga was at serious risk from being altered beyond all recognition. The lake was saved only by the sharp eyes of DOC staff member Brad Edwards and a secure surveillance programme.
Purple loosestrife
The risk was the 'purple peril', an aquatic weed better known as purple loosestrife. Purple loosestrife (Lythrum salicaria) is a serious threat to New Zealand's unique wetland biodiversity. This invasive weed can irrevocably change the habitat of wetland and waterway sites and once established it is difficult and costly to control - so the answer? Nip it in the bud.
'Nipping them in the bud' is the best we can do for many of New Zealand's invasive weeds, and the Department of Conservation has a surveillance system that helps ensure the early detection of invasive weeds.
Surveillance is about finding new weed infestations when effective action is still possible and before the cost of control becomes too high. Surveillance offers our best hope of changing the trend of an ever-increasing number of invasive weeds and invaded habitats. Weed surveillance involves DOC staff actively hunting for weeds. But as many eyes as possible are needed for surveillance to really work, and we can all be involved.
Members of the public have been the first to spot many major pest invasions in New Zealand in recent years, so public education is crucial. In the Wellington Region alone, over 300 new weed sightings have been recorded in less than three years. These sightings have not just come from DOC weed staff. Other DOC staff, members of the public, and staff from the regional council, have all helped.
Wellington Conservancy Technical Support Officer, John Sawyer says; "Surveillance in Wellington is enormously important. If it wasn't for the constant vigilance of DOC staff, regional council staff and members of the public, Kapiti Island would be infested with Old Man's Beard, purple peril would be clogging Lake Papaitonga, and countless new weeds would be threatening the unique natural ecosystems around Wellington."
John attributes this surveillance success to a combination of training, active hunting, public awareness, good baseline information and rapid follow-up control. The rescue of Lake Papaitonga from the perils of purple loosestrife is thanks not only to the sharp eyes of DOC staff, but also due to good training in weed identification.
In another success story, a member of the public phoned in to report a weed from the Wellington Conservancy fact sheet "Have you seen these plants in Wellington Conservancy?" (PDF, 560K). Publications and public information have also been central to surveillance success stories on the Chatham Islands, and a biosecurity booklet published in 2002 has resulted in Chatham Islanders reporting invasive weeds and animal pests.
Other strings to the weed-surveillance-bow of Wellington Conservancy are the Weed Atlases (Volume One and the recently completed Volume Two). These publications contain baseline information about the distribution of weed species and empower everyone to be involved in weed surveillance. You are encouraged to record any new weed sightings on surveillance forms (PDF, 20K) and hand them in to a DOC office near you.
Weed surveillance is something everyone can get involved in. Contact DOC weeds staff for information about invasive weeds to watch for in your area - whether you're walking in a reserve, motoring on a lake, or driving through the neighbourhood, you can make a huge contribution to conservation by keeping a look out for weeds.
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