Efforts to eradicate the aquatic weed pest lagarosiphon from Lake Wakatipu have been successful, but authorities will remain vigilant about a return of the weed.
Monitoring inspections completed earlier this year also showed the continuing effectiveness of control work done in Lake Wanaka, with fewer infested sites being found outside `known infestation' areas, a report to the Otago Regional Council's compliance committee said.
Environmental Services manager Martin King said in his report, the expertise, knowledge and regular monitoring of council and Niwa had enabled the early detection, identification and eradication of the weed from Lake Wakatipu.
However, the risk of the weed being carried back into the lake was high, given the many boat users using the lagarosiphon-infested Lake Dunstan, he said.
