"Council officers inspected the site, and Biosecurity New Zealand is planning an extensive survey of the coast 15km north and south from where the original plant was spotted. While no further plants have yet been found, we know this weed spreads quickly and could cause significant damage if it became established.
"So, we're asking beach users in Ōakura and along the coast to keep an eye out and report any possible sightings."
Sea spurge (Euphorbia paralias) looks like a small shrub and can grow up to about half a metre in height. It has multiple stems that are often reddish at the base with slender, tightly packed bluey-green leaves and greenish flowers on the end of the stems.
Sea spurge sap can cause skin and eye irritation, and there is a native plant species that looks very similar, so people should not try and remove it.
Instead, they should take a photo of the location and a close-up of the plant, note its exact location, and then call Biosecurity New Zealand's pest and disease hotline on 0800 80 99 66.
Biosecurity New Zealand and the council will monitor the site over the coming months and years to ensure any further spread is detected and controlled.
For more information see www.trc.govt.nz/shore-spurge-and-sea-spurge/#sea.