Week in Review

How this seaweed could slash dairy emissions

Seaweed harvested or farmed off the coast of Stewart Island by a Kiwi company could prove the key to decreasing methane emissions from livestock globally, Marc Daalder reports

When Robert Kinley first saw the results from his experiment with feeding cows various strains of seaweed, he assumed his equipment had malfunctioned. After resetting the equipment, he got the same result. So he ran the entire test again.

Same result.

Only then did it begin to dawn on him that he had stumbled on something extraordinary. Asparagosis taxiformis, a species of seaweed native to south Australia, Tasmania and the South Island of New Zealand, reduced methane emissions from cattle by more than 90 percent.

Now, CH4 Global, a company founded by New Zealand entrepreneur Nick Gerritsen, has seized the opportunity - and half a million dollars in Provincial Growth Fund grants - to make New Zealand the epicentre of a new seaweed rush.

Asparagopsis a big promise

It's not much to look at, but the almost-feathery pink seaweed promises a lot. Methane reductions of up to 90 percent are nothing to sneeze at. Methane makes up 42 percent of New Zealand's total emissions and farmers opposed New Zealand's Zero Carbon Act pledge to reduce methane emissions by 47 percent by 2050.

The science is relatively new - Kinley's groundbreaking study about the potential of asparagopsis only came out in 2015 - but no one has yet refuted it. Prior to that, Kinley had been working with the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia's national science research agency, to discover what species of seaweed or other algae would have the greatest impact on methane emissions.

Asparagopsis armata off the coast of Stewart Island. Photo: Sasi Nayar

Kinley's 2015 paper makes some pretty astounding claims. The researchers had included asparagopsis at varying amounts in the diets of cattle and then monitored their methane emissions over the next 72 hours. "The inclusion of Asparagopsis had the effect of reducing [methane] production in a dose and time-dependent manner," Kinley and his co-authors write.

The study found that "the prominent effect occurred at dose levels >2% (P < 0.001) and no detectable [methane] was produced" (emphasis added). Adding asparagopsis to cattle diets "at >2% demonstrated virtual elimination" of methane.

The below chart from the paper illustrates the varying effectivenesses of an asparagopsis diet, depending on how much of the diet consists of the seaweed. At or just above two percent appears to be the optimal amount - the study found that when asparagopsis made up 10 percent of the animal's diet, the cattle had more trouble digesting.

How does it work?

Kinley's team is still working to discover exactly what it is that makes asparagopsis tick. However, the basic summary is that it functions as an enzyme inhibitor, stopping the processes that produce methane in the animal's gut.

The seaweed appears to reduce methane emissions from all domesticated ruminant animals - mammals like cows, sheep and goats that ferment plant matter in a specialised stomach in order to digest it. No animal is capable of independently digesting the sort of plant cellulose that makes grass such a tough plant, so ruminants use bacteria, protozoa, yeasts and fungi in their stomachs to break down the cellulose.

When the resultant sugars from the cellulose are further broken down by the ruminant's stomach bacteria, by-products like lactate and propionate - which help produce good milk - and methane are created.

The microorganisms which produce methane, methanogens, are the subject of a considerable amount of research. Kinley says that properties of asparagopsis inhibit these methanogens in particular, while not affecting other bacteria. In fact, he says, the lack of methanogenesis means more proprionates can be created, leading to better milk.

While scientists aren't totally certain about what aspect of asparagopsis serves as the enzyme inhibitor, they've observed a correlation between the amount of the chemical bromoform in the asparagopsis and the magnitude of methane reductions. In other words, more bromoform seems to indicate less methane.

Precedent for feeding seaweed to cows

Cows have long fed on seaweed, Kinley says. "There are tales of the Ancient Greeks letting their cattle roam free and the animals would eat seaweed on the beaches to supplement their diets," he told Newsroom.

Asparagopsis armata collected off the coast of Stewart Island. Photo: Marc Daalder

Alan Groves, a co-founder of CH4 and the company's chief operating officer, told Newsroom that he had heard similar anecdotes from farmers in New Zealand who own beachfront properties.

In fact, Kinley first stumbled onto the potential for methane reduction via seaweed consumption through a Canadian farmer who found his cattle were more productive when they ate storm-tossed seaweed in 2005. The farmer, Joe Dorgan, had left some of his livestock in a paddock by the sea and these produced more milk than their landlocked counterparts.

Dorgan rang up Kinley, who had been researching the possibility of using seaweed and other algae as nutritional supplements for livestock, and was at the time one of the few experts in feeding seaweed to cattle. Kinley ran a wide series of tests on Dorgan's landlocked and beachfront cows, primarily aimed at understanding the impact on their health and production.

However, by pure luck, Kinley also tested for methane emissions. The results of these tests showed that the seaweed-eating cattle produced about 20 percent less methane than the grassfed ones. Kinley dug deeper and by 2013 he was working at CSIRO, testing different species of seaweed. That's where he stumbled onto asparagopsis, which his first test indicated had completely eliminated methane emissions, and thought his equipment had to be faulty.

Company not alone

Gerritsen has invested in numerous technology and climate change-related projects, including a stint in the early 2000s producing biofuel to power airplanes more sustainably. CH4 Global is his latest effort and it already has a vote of confidence from the Government in the form of $500,000 from the Provincial Growth Fund.

The Cawthron Institute, known for its aquaculture park and research team, has also picked up some Government funding to investigate asparagopsis. In October, Cawthron received $100,000 from MPI and has bolstered that with $150,000 from its own coffers. Cawthron's project is linked with the University of Waikato and Australia's James Cook University, as well as some of the scientists who worked on the 2015 study with Kinley.

"If you think about aquaculture or any primary sector, you can harvest wild resources, but many years ago it was realised globally and nationally you can't keep doing that," said Charlie Eason, the institute's chief executive.

One of mussel farmer Jim Maass-Barrett's lines in Big Glory Bay. Photo: Marc Daalder

"There's a global recognition that you can harvest the wild but to meet the [millions] of tons that would be needed in a sustainable long-term way, you need to actually figure out how to grow it. At our aquaculture park, we're looking at this seaweed species, how to best breed it, how to best grow it, as you would with terrestrial plants."

"It's a race to produce quantity. Where do you produce quantity? Okay, you can get it from the wild but if you really want to have biomass for the future - and this is going to be something that's worthwhile - you need to work out the best ways to grow it."

Eason says Cawthron's focus on farming techniques and quality assurance is complementary to CH4's work on harvesting and surveying New Zealand's natural resources.

CH4 seeks to mass harvest, farm

CH4 - that's the chemical formula for methane - has been operating on the sly for a year, with partnerships with the University of Otago's Marine Science team and NIWA. The company has a permit from the Ministry for Primary Industries to harvest naturally-occurring wild asparagopsis for research and development purposes. It is currently seeking permission from the Ministry to begin farming trials.

Local shellfish farmer Jim Maass-Barrett, who lost his oyster farm to an outbreak of bonamia ostreae in 2017 and just recently restarted a mussel farm in Stewart Island's Big Glory Bay, will take the lead on any potential farming for the company.

Maass-Barrett isn't the only local working on the project - Groves whakapapas to Rakiura and CH4 has acquired the services of sixth-generation Stewart Islander Zane Smith. Smith is a boatie, businessman and Maass-Barrett's partner on the new mussel farm. He's been monitoring the wild population of asparagopsis around the island and collecting it for research purposes.

Smith has also spent some time devising a tool for harvesting the seaweed in greater quantities, using some form of vacuum. Michael Lakeman, a New Zealander who spent 10 years at Boeing heading up their efforts to create a biofuel to replace jet fuel, is also involved with CH4. His title is VP of Operations but he's embedded with the science team, putting his years of work with algae at Boeing to use for the Kiwi company.

Seaweed resources abundant

When it goes commercial, the company hopes to start with harvesting wild seaweed and then slowly phase that out as its farms grow in scale. Scientists from the University of Otago have been conducting surveys of the area's asparagopsis population in order to determine whether and how to sustainably harvest it.

Early indications are that New Zealand has a bounteous amount of asparagopsis. Scientists from Australia who recently visited Stewart Island, including Kinley, told Newsroom that a patch of asparagopsis of average density for the region would be incredibly dense by Australian standards.

Asparagopsis armata off the coast of Stewart Island. Photo: Sasi Nayar

The specific species present in New Zealand's colder waters, Asparagopsis armata, has been subject to less research than the Australian Asparagopsis taxiformis, but Kinley says its properties are nearly identical.

That lends hope to CH4 that they'll be able to harvest the seaweed sustainably while they iron out the kinks of the farming system. Seaweed farming isn't new - it's farmed in vast quantities in Japan and elsewhere as food for humans and nutritional supplements for animals - but Groves said he hadn't heard of anyone farming asparagopsis quite yet.

The algae is fragile and easily falls apart in the water, meaning that even if a rope is seeded with asparagopsis spores and they grow abundantly, it might be difficult to collect the seaweed from the rope without losing a significant amount in the process.

On the visit to Stewart Island, the Australian visitors and Maass-Barrett traded ideas for how the farming could be accomplished, including whether to use ropes, some sort of mesh, or a different tool entirely.

Dairy farmers cautious

Representatives of the dairy industry, including DairyNZ and Fonterra, have reacted cautiously to the news of asparagopsis.

"Currently, DairyNZ is involved in research into methane emission mitigation and we welcome the investment and research into new options taking place in New Zealand and overseas, to help farmers reduce their emissions," DairyNZ's strategy and investment leader Dr. Bruce Thorrold told Newsroom.

"At this point, DairyNZ isn’t planning on carrying out research with red seaweed but we are following its potential and may be involved in future research."

Fonterra was more skeptical. A spokesperson highlighted the cooperative's 2019 Sustainability Report, which raises questions about feeding cows uniform amounts of feed or feed supplements. "To maximise the effectiveness of inhibitors administered through supplementary feed, the cows would need to spend more time in sheds or on feed pads being fed the special feed," the report states.

"This not only increases the farming costs, it is at odds with the growing consumer interest in pasture-based cows. This means our focus is on inhibitors that can be fed at milking time, and then reduce emissions while the cow is back out on the pasture."

The Fonterra spokesperson also pointed Newsroom to a Stuff article from 2016, in which scientists raised concerns about the use of asparagopsis to reduce methane emissions. The scientists quoted were concerned about the possible carcinogenic effects of bromoform and its impact on the ozone layer.

Kinley has said that little research has been conducted into carcinogenic effects of bromoform, pointing to just one study where mice were dosed at 1,500 times the levels that cattle would ingest the chemical. On the ozone layer, Kinley told Stuff, "At some point we have to make judgment calls. I know it's not good to replace one problem with another but the problem of bromoforms haven't been quantified whereas the benefits of the seaweed are far reaching."

A spokesperson for Agriculture Minister Damien O'Connor told Newsroom that the Minister "views the native red seaweed Asparagopsis armata as an algae with a lot of potential. If successful, [asparagopsis] could be a game-changer for farmers here and around the world. In previous trials, asparagopsis has proven to reduce greenhouse gas emissions in livestock by up to 80 per cent. Other products typically provide reductions of between 10 and 20 per cent."

O'Connor was unable to specifically comment on CH4.

*Marc travelled to Stewart Island at Newsroom’s cost, but Nick Gerritsen put Marc up for two nights on Stewart Island. Nick is also on the advisory board of Press Patron, which collects donations for Newsroom and keeps a percentage to cover its costs.