Northland seaweed operation aims to cut down greenhouse gases

Whangārei MP Emily Henderson, Minister for Climate Change James Shaw, CH4 technician Hollie Keropa, CH4 Aotearoa's Nigel Little and CH4 Global's Tim Williams were among those who attended Tuesday's event. Photo / Jaime Lyth

Tank-grown seaweed in Northland is being heralded as the solution to reducing the dairy industry's harmful emissions and saving the planet.

The CH4 Aotearoa opening of its "world-leading" Asparagopsis facility attracted a diverse crowd of listeners at Niwa's Northern Aquaculture Centre at Ruakākā on Tuesday.

CH4 Aotearoa has been developing seaweed farming systems focusing on the production of the Asparagopsis species.

The Asparagopsis seaweed produces a bioactive compound called bromoform which prevents the formation of methane in the gut during the digestion in animals such as cattle.

Almost half of New Zealand's total greenhouse gas emissions come from agriculture, mainly methane, which is produced by livestock such as sheep and cattle - primarily through burping.

According to some trials, mixing a small amount of the dried specialised seaweed is mixed into the feed of cattle can reduce its methane production by more than 90 per cent, despite equivocating to only 0.5 per cent of the animal's diet.

Some of CH4 Aotearoa's Asparagopsis seaweed up close at Niwa's Northern Aquaculture Centre in Ruakākā. Photo / Jaime Lyth

The Ruakākā facility is already producing tank-based seaweed material at a pilot scale, as well as a promising hatchery and nursery technology to develop larger farming operations.

It wasn't until April this year that the team divided to pivot from marine-based to land-based growing of the seaweed, which reduces the environmental impacts on the ocean.

Speakers at the event included Helen Neil from Niwa, CH4 Global chief operating officer Tim Williams, Climate Change Minister James Shaw and CH4 Aotearoa chief science adviser Dr Michael Lakeman.

"Seaweed is an underutilised marine resource," said Williams.

He said it's important to consider how we can use underwater plants commercially like we use land-based materials such as bamboo.

The potency of the seaweed and the small amount of space needed to grow the product leads Williams to believe the programme could one day supply the whole New Zealand dairy market.

The impacts of climate change have been hitting regional New Zealand hard this year, Green party leader Shaw pointed out.

"We have people in this country in this last 12 months who have sandbagged their house for the fourth time, whose roads have been washed out three to six months apart from each other and (Northland) is no stranger to that phenomenon."

Shaw said it was important to address the climate crisis on a global scale and it was great to see New Zealand initiatives involved in that.

He added the scheme was not only exciting for the impacts it will have on climate change but also for creating new jobs for people in the regions.

"It's fantastic that somebody can go and get their science degree and actually come back home and earn a good salary doing meaningful work using the specialisation that they trained for," Shaw said.

There has been a number of challenges along the way, but so far nothing the team hasn't been able to overcome said CH4 aquaculture systems technician Hollie Kereopa.

"It makes all the difference that I can come to work and know I'm making difference."

CH4 aquaculture systems technician Hollie Kereopa is one of the many young workers at the Ruakākā site working to find solutions to climate change. Photo / Jaime Lyth

Kereopa has been working at what she describes as a "dream" job for two years now, she grew up in Waipu and studied in Wellington before returning home to Northland.

"I'm really excited, we started with 30-50 grams of seaweed and everything on site has grown from that."

A 2-litre tank and 30 grams of seaweed have now expanded to 30,000 litres and 300kg of seaweed under the hard work and supervision of Kereopa and her team.

Current challenges include lighting and incubating the seaweed on large scales, but things are looking positive as the commercial harvest of the seaweed began in July this year.

"It's a natural way to stop climate change. I have full confidence in it," Kereopa said.