New Zealand aquaculture businesses are being encouraged to grow a seaweed that can be marketed as a methane-busting livestock.
An aquaculture start-up says it is accelerating plans to commercially cultivate Asparagopsis armata and is offering its expertise to anyone wanting to farm it.
Asparagopsis armata - the methane-busting seaweed Photo: supplied
CH4 Global was founded by a group of local tech and bioscience entrepreneurs developing the feed product made from the native red seaweed, which grows in New Zealand and South Australian waters.
Trials have shown the seaweed feed can reduce methane produced by cows by up to 90 percent.
CH4 Global president and chief executive Dr Steve Meller says the company has recently successfully cultivated all the life cycle stages the seaweed and it will move to speed up commercial expansion of operations in New Zealand and Australia.
He tells Kathryn Ryan existing fish farms would benefit from growing and cultivating the seaweed in multiple ways, because the plant feeds on nitrogen produced by fish, meaning they could potential increase their stock limit.
The company recently raised $4.5 million in seed funding. The product is being led scientifically by the South Australia Research and Development Institute and Dr Chris Hepburn, of the University of Otago.
Dr Meller says the company has advanced since getting government funding to establish a processing plant in Southland last year, with advances in understanding the end-to-end cycle of the producing the material.
“We have much more control now over where to grow it and how to grow it and in which ways to grow it.
“More importantly we’ve also been spending a large amount of resources, time and money on understanding the processing of it and it’s really very important, because of the plant itself contains a volatile material called bromoform and it’s bromoform that actually imparts that methane-reduction on ruminant animals.
“So, it’s really, really important that when you harvest it from the water, whether it’s growing in tanks or whether it’s in the sea, through to when it’s going to be given to a cow or sheep, that you maintain the level of bromoform inside the plant. So, the conditions in which you process it are critically important.”
The company plans to build the first commercial scale asparagopsis aquaculture and processing facility, which will be located in south Australia. Other sites have been identified, including the one in Southland.
Each facility will supply between 10,000 and 20,000 cows.
The process is specialised and has been formulated from extensive scientific research and expertise.
Young plants will be grown on land, put on substrates and those substrates will go out on a long line into the ocean. Between 45 and 65 days, these are harvested similar to the way mussels are. It is frozen and mulched, before being freeze-dried, shredded into a finer material. It is then packaged, stored and dried.
The seaweed can be sprinkled into feed or packaged as a full snack for cattle.
The technical details for growing and processing the product is being open sourced. The commercial benefits to New Zealand fish farming is apparent, he says.
“What we want to do in New Zealand, particularly, is actually encourage everyone who is interested, who already does aquaculture, to actually grow it and if you are an existing fin-fish fisherman down in Southland, you are restricted to stocking capacity of whatever fish you are growing.
“Salmon is an example and you are restricted on the basis of the nitrogen output of those fish. If seaweed, asparagopsis in this case, is planted downstream, one of the foods it likes to eat is nitrogen.
“And so all of the fish affluent would be taken up by the seaweed and actually the calculations we’ve done with the South Australian regulators, is to be able to significant increase stocking capacity.
“So, it is entirely feasible that a fisherman today in Southland could increase stocking capacity, decrease costs not having to move those pens around and have a third revenue stream of asparagopsis that we would teach them how to farm, that we would buy back from them at cost, plus a margin of profit.”
Dr Meller says there are no environmental impacts from farming the native seaweed, and growing it helps in a small way to address ocean acidification.
