Sea spurge – what is it, and why is it bad?

Sea spurge – what is it, and why is it bad?

You may have seen in the news that there has recently been a significant sea spurge infestation found in Northland – Battle begins to eradicate toxic species that can temporarily blind after largest infestation to date – NZ Herald.

Sea spurge is an invasive weed that can quickly take over our dunes, push out our native plants and destroy shorebird habitat. It is also toxic – the sap can burn skin and even cause temporary blindness. The seeds travel from from Australia on ocean currents and could wash up anywhere in New Zealand, particularly on the west coast.

Many beaches in Australia have now been completely taken over by sea spurge (see Turning the Tides on Sea Spurge – Wildcare) and we can only stop that from happening here by constantly being vigilant.

What can I do?

Please keep an eye out for sea spurge while you’re out on the beach – locals are our first line of defence in the fight against this menace. Sea spurge is usually found on dunes or among washed-up debris on beaches. We have a lot of isolated beaches in the Waikato region, so there is a chance that at least one beach in the Waikato has a population establishing already. The more people keeping an eye out for it on beaches this summer, the better.

What does sea spurge look like?

• Sea spurge looks like a small shrub, usually up to half a metre tall.
• It has multiple stems, often reddish at the base.
• It has distinctive, spiky, tightly packed blue-green leaves that are 4-20mm long and 1-16mm wide.
• It has greenish flowers on the end of the stems.

Are there any similar-looking native species?

Yes, there are two rare native coastal plants that can look similar to sea spurge, but they have other features that are different.

• Euphorbia glauca/ Waiu-atua looks similar, however its leaves are much longer – 30-80mm.
• Linum monogynum/ Rauhuia looks similar, however it has white flowers.

What should I do if I find sea spurge?

• Do not handle the plant, as this can spread the seeds. The toxic sap can cause injury if the stems are broken or cut.
• Take clear photos of the site and the plant, with closeups of the leaves and flowers.
• Record your location accurately (use Google maps or GPS if possible).
• Report any sightings to MPI on 0800 80 99 66 or online at https://report.mpi.govt.nz/pest/