Skip to main content
Published: 2009-08-05 00:00:00

Environment Waikato has made a submission to MAF Biosecurity New Zealand signaling its support for the commercial harvesting of the invasive seaweed Undaria pinnatifida – but only in areas where it is already established.

The council is opposed to the farming of undaria.

Undaria is an Asian seaweed species that was accidentally released into New Zealand and has become relatively widespread.  Some types of undaria are edible and there may be a commercial market for it in Japan, but the market opportunities are not well established.

Environment Waikato’s submission says the commercial harvesting of undaria should be limited because it of its potential to invade and irreversibly modify a wide range of marine communities.

“However, the council also recognises that there are instances in which it may be possible to make a commercial profit from existing undaria infestations without increasing the ecological risk to the coastal environment,” the submission says.

The council has made it clear in its submission that it does not support farming of undaria, and strongly believes the weed should remain an unwanted organism under the Biosecurity Act.

“Retaining this status will ensure national management of a pest that the council believes is a national responsibility.  In contrast, removing ‘unwanted’ status would represent a move away from the Crown taking primary responsibility for marine pests,” the submission says.

The council’s submission is in response to a review of MAF Biosecurity New Zealand’s Undaria Commercial Harvest Policy. 

MAF has asked for feedback on whether to allow more commercial harvesting of undaria, and whether the species should remain classified as an unwanted organism under the Biosecurity Act.

Earlier this month, Environment Waikato’s regional pest management committee had signalled Environment Waikato should make a submission supporting harvesting of undaria, but only where it was already occurring naturally, and only when harvesting was part of a control programme.

However, after extensive discussion at its recent meeting in Hamilton, the full council opted for a more flexible stance.

At the meeting, Coromandel councillor Simon Friar said he would support the farming of undaria in heavily infested areas.

“Seaweed’s moving anyway and would be naturally dispersing its seed.  Harvesting and farming in infested areas will not aggravate the situation.  There is potential for providing wealth and jobs to the country.”

But Taupo councillor Laurie Burdett disagreed, saying farming the species would accelerate its spread around New Zealand and might encourage people to import genetic material from overseas.

South Waikato-Rotorua councillor Norm Barker said he did not support farming of the weed, but would be comfortable with the harvesting of undaria in areas where it was already occurring naturally.

“There is potential for a commercial crop, so it’s logical to take the opportunity to derive economic benefits from it,” he said.

Hamilton councillor Paula Southgate said Environment Waikato’s primary focus should be on preventing and controlling biosecurity risks.

“We need to be careful about setting a precedent where we back off controlling something that is an invasive pest just because it may also have commercial potential.”

Waipa-King Country councillor Andra Neeley said if the unwanted organism status of undaria was changed, Environment Waikato would be responsible for managing the species under its Regional Pest Management Plan, creating potential headaches and costs for the council.

Councillors eventually agreed unanimously to make a submission supporting commercial harvesting of undaria anywhere it was already growing naturally, as long as it did not increase the ecological risk to the coastal envrionment.  The council did not support farming of the species and wanted it to remain an unwanted organism.