A joint Biosecurity New Zealand and Waikato Regional Council work programme is underway following the discovery of a small cluster of pest water hyacinth in the Waikato River near Huntly.
The agencies are working together with local iwi to ensure any water hyacinth present is located and safely removed. The team will then coordinate ongoing checks to make sure it hasn’t come back.
Biosecurity NZ manager of pest management, John Sanson, says water hyacinth is a rapidly growing water weed that if left, can form dense mats that reduce water quality, crowd out native water plants and animals, block irrigation systems and alter ecosystems.
“In this instance, we’ve found just two individual plants in the slow waters at the edges of the river and one plant in a cluster of willows further out into the stream.
“The plants have clearly come from a container of water hyacinth being kept at a private property in Huntly backing onto the river. This container was close to a drain next to the river bank and we believe that’s how the plants entered the waterway.”
John says all known plants have been removed, inspections have found no further weed, and a boat survey was undertaken. Now the area will be regularly surveyed for 20 years to ensure the plant doesn’t come back.
John says it is illegal to sell, propagate or distribute this plant. “If people believe they’ve seen it, please contact our pests and diseases hotline 0800 80 99 66.”