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Published: 2012-01-13 00:00:00

The highly invasive pest plant known as purple loosestrife has been discovered in Waikato for the first time at Lake Moananui, near Tokoroa.

A regional council contractor confirmed a single plant sighted was purple loosestrife after it was discovered by a local out for a walk around the lake.

Under the region’s pest management strategy purple loosestrife is classed as a potential pest and the plant was removed promptly by council staff.

Biosecurity officer Wendy Mead said it was unclear how the weed was brought into the region.

“It has possibly hitchhiked from another region as seed on a kayak.

“This highlights the importance of cleaning boats and other water equipment, such as fishing gear, when moving from one waterway to another. This helps avoid spreading serious plant and other pests, including didymo which is not present in the North Island.

“The discovery also highlights how the region is always prone to new infestations of plant pests and we ask the public to remain vigilant for anything that looks out of place.”

Purple loosestrife is a tall perennial herb, which is native to Europe and Asia. It has purple flowerhead spikes over the summer months.

Purple loosestrife rapidly invades damp ground and shallow water, forming massive, thick stands that shade out smaller plants. It destroys wetlands and water margins, causing blockages and flooding, and removes food sources for many fish and bird species.  It produces millions of long-lived, highly viable seeds from an early age which are spread by water, contaminated machinery, soil, livestock and hay. If people think they have seen this pest please phone 0800 BIOSEC (246732) to report it.