In 2021 a dangerous plant called Sea Spurge was found at Waikawa Beach in the dunes north of the river. It has established in an area 10 metres by 10 metres.
Do not touch this plant as it is toxic.
The plants have not been removed, or marked off, as authorities want to study them and do not want to attract attention to them. They are inspecting the area regularly and monitoring closely.
Horizons Regional Council says:
Sea spurge is a pest plant we have recently found in the dunes at Waikawa Beach. We know it is in four other locations along the Horizons region coastline. We need your help to track down any other sites across our region. Sea spurge can quickly out-compete other plants that protect our sand dunes.
⚠️ What’s more, its sap is harmful to both people and animals – causing skin irritation and even temporary blindness.
📞 If you think you’ve found sea spurge, do not try to remove it. Instead, call Biosecurity New Zealand on 0800 80 99 66 to report it. For more information head to www.biosecurity.govt.nz/seaspurge
Sea spurge (Euphorbia paralias) is a potentially serious coastal environmental weed. It is native to western and southern Europe and is now well established along the Australian coastline. Seeds can survive up to six years in sea water and up to about 15 years in ideal conditions on land.
The pest plant poses a serious threat to the ecological and physical structure of sand dunes. If it establishes here, sea spurge could overrun many native dune species including spinifex, pingao and a number of sea grasses. It could also threaten the habitats of native birds such as dotterel and terns.
Members of the public are encouraged to report any suspected sightings as soon as possible because early detection offers the greatest chance of getting rid of this weed.
If you think you’ve found sea spurge, please contact Biosecurity New Zealand’s pest and disease hotline 0800 80 99 66. They will tell you what to do.
Please do not disturb the plants as moving them could spread seeds, and breaking stems releases the milky sap which is toxic and can cause skin and eye irritations.
Also, sea spurge looks very similar to the threatened native species Euphorbia glauca and the New Zealand linen flax, Linum monogynum, and we don’t want these accidentally removed. Ideally, take a photo and note the location as accurately as possible – GPS coordinates are ideal.
What it looks like
Sea spurge plants can grow in dense clusters or as individual plants up to one metre tall. Plants have multiple stems that are often reddish in colour at the base. The blue/green leaves are spiky, tightly packed and about 4-20mm long and 1-16mm wide. Green flowers bloom at the stem tips, mostly during the warmer months, and the flower stems die off each year after flowering.