Fears about a new marine pest in Northland have proved to be a false alarm.
A resident at Taurikura Bay, south-east of Whangarei, contacted Northland Regional Council to report a rapid spread of a grass-like marine plant in the inter-tidal area.
It's been identified as a beneficial native sea-grass, known to Maori as rimurehia.
The council says sea grass acts as a 'living filter' for sediment and nutrients running into coastal waters, as well as being a nursery for fish such as young snapper.
Estuary management advisor Jon Hampson says the spread of the species in Taurikura Bay is positive at a time when seagrasses internationally are being lost at a rate of about 2% - 5% per year.