30 Jun 2022

Large-scale spirulina production helping improve returns on marginal land

10:57 am on 30 June 2022

A project looking into the viability of large-scale spirulina production in New Zealand is going well, with plans to move the production base to Palmerston North.

spirulina in hands

Photo: Public domain

In November 2020, the government and NZ Algae Innovations announced a $250,000 project to see if the algae could be grown in New Zealand on a commercial scale.

Spirulina, which has high levels of protein and iron is used as a health supplement and is often sold as a green powder.

NZ Algae Innovations had already set up the country's first spirulina farm on the outskirts of Himitangi in Manawatū-Whanganui in 2019, but wanted to increase its scale.

The farm had a 400sqm area dedicated to growing spirulina in purpose-built shallow ponds, where the algae would be cultivated, harvested and then dried.

Company spokesperson and Massey University professor Benoit Guieysse said the research project was going well, but Whanganui actually proved too sunny for the algae.

"We were quite surprised, we thought that the sunny location was going to be the best for growing spirulina," he said.

"But now we're not quite sure, because it grows so fast in summer, you have to constantly harvest the biomass and things can go wrong quite easily.

"So, we actually think in the new location, that is slightly more cloudy, will be better.

"We thought we're gonna get really big productivity in summer, and we did, but it was quite challenging."

Guieysse said because of this, the spirulina research would now be moved to Massey University's Palmerston North Campus, where the conditions were better-suited.

But he said keen spirulina growers should not fret, as greenhouses can be purpose-built to provide the best growing conditions for the algae.

He said the Covid-19 pandemic had delayed the scaling project and it would likely take another two years.

The project aims to establish a new business model, so modular production units can be replicated in potential growing regions across New Zealand, and build on the existing base of knowledge about spirulina production to grow a more nutritional product.

It will explore ways of maintaining more nutrient content in spirulina by developing different harvesting and processing methods using techniques from other industries.

Spirulina can be grown using most land types, providing the opportunity to improve returns on marginal land.

There is also potential for a spirulina sector in New Zealand to utilise waste streams from other primary industries as a source of nutrients for spirulina growth.