<- Back to: News

Giant kelp (Macrocystis pyrifera) is the fastest growing and most prolific of all plant species found on Earth.

That is according to prominent international biologists David Schiel and Michael Foster.

In addition to a fast growth rate, up to 50cm per day, and an adult size of up to 60 metres, giant kelp produces millions of spores that are capable of colonising rocky substrate in a range of conditions, becoming reproductive in less than a year.

It is a wonder plant, also known as bladder kelp, that was introduced to New Zealand’s Quota Management System (QMS) in 2010.

Since that time, Roger Beattie’s NZ Kelp has harvested 400 tonnes, largely in Akaroa harbour.

Only the canopy section is taken, cut to a maximum depth of 1.2 metres, with no decline in the health of the kelp forests.

Harvesting of giant kelp along the Californian coastline has been sustainable since the early 1900s. It reached a peak in World War I when 400,000 tonnes were taken to produce potash for gunpowder.

In this country it is prized by organic food producers selling dried vegetable products, as a stock feed supplement and as a crop spray that raises brix (sugar) levels and inhibits insects and disease.

Beattie believes a proposed South East Marine Protection Forum from Timaru to Waipapa Point in Southland and a smaller 20-km taiapure centred on Waikouaiti north of Dunedin that would ban kelp gathering are tantamount to theft of quota and is gearing up for legal action.

He is critical of a lack of consultation and a lack of understanding of the properties of seaweed.

Giant kelp is a giant opportunity, he says.

He has invested heavily, doubling his staff to four, buying a new cutter, importing a new dryer and buying a new vessel.

He expects to double production next year, provided he retains access, and double it again in 2021.

Most harvesting occurs in spring before the usual summer die back.

“We’re having no problem selling,” he says.

“We also sell to dog food manufacturers and that market is going flat out.

“They want the human grade product, despite it being twice as expensive as the animal grade.

“People are willing to spend a lot of money on their pets.”

The premium grade Valere product sells for between $40 and $74 a kilo.

Giant kelp has the highest iodine content of any plant, a mineral deficient in New Zealand soils.

It is also high in alginates, a group of chemical compounds used as thickeners and gels, found in toothpastes, ice cream and pharmaceuticals.

Beattie, who farms Pitt Island wild sheep on two Banks Peninsula properties, was a giant kelp pioneer, co-funding with the Foundation for Research and Technology the country’s largest kelp harvesting research project, which led to the current commercial production.

“Applying kelp to soils improves its health, increases the production per hectare and improves the resilience,” he says.

Tests with a variety of crops, including brassicas, carrots, barley, onions and beet, have shown sharp increases in yield.

“Global demand for seaweed is rising and with New Zealand’s isolated geography, relatively clean waters and world class QMS, we are in the prime position to capitalise on this opportunity,” Beattie says.

“The number of products is expanding and sales are increasing, providing sustainable eco-friendly products to a multitude of end users, whilst also providing valuable employment and income for New Zealanders.

“An unthinking banning of giant kelp harvesting will put a stop to that.”