Red Seaweed Research

A native red seaweed used in stockfeeds has the potential to reduce methane emissions from ruminants.  The Cawthron Institute has received funding to investigate the best ways of producing it in huge quantities. 

Asparagopsis armata is a red seaweed that is endemic in waters around New Zealand. Early studies suggest that as little as 2% added to stockfeeds could reduce methane eructation by up to 80%. Australian research suggests that if 10% of global ruminant producers used this product in livestock feeds it would be the equivalent of removed 50 million cars from the world’s roads! Even allowing for political hyperbole the potential for this seaweed is significant if only it can be grown on a scale large enough to feed all New Zealand’s dairy herds. 

Asparagopsis is a relatively small seaweed and not a lot is known about its culture and growth habits. Scientists need to determine how it reproduces and what conditions are best for growth. Will it thrive only in warmer waters or can it be grown anywhere? Should plants be attached to something or floating?  Are there ‘fertilisers’ that will make it grow more rapidly? Are there some strains that have higher content of active ingredients than others? Which part of its life cycle is most suited to different production systems (e.g. land-based, nearshore etc.) and which is best to produce the active ingredient? 

These are questions that scientists at the Cawthron Institute in Nelson are considering. Science Leader Algal Research Dr Johan Svenson says that they are now at the stage of studying in detail the life cycle of the seaweed to be able a grow and generate it on demand. “Even though it is a seaweed its reproduction is quite complex so we are trying to understand how to get it to reproduce in a controlled fashion on a small scale, so we can optimise the growing conditions on a larger scale,” he says. “We are at the stage of growing small quantities to examine in detail.” 

At present the group is studying what they call the “pom-pom” stage of the life cycle – the seaweed forms pom-poms that float or sink – and they have collected many samples from different locations around New Zealand so that they can examine genetic variation.  The pom-poms are tetrasporophytes, adult tissues that are present in summer and can be grown continuously under the right conditions. They preceed the gametophyte stage, which is a bigger plant that can be found attached on marine structures. 

“We want to understand what triggers the pom-poms to proceed to the next part of the life cycle. Asparagopsis is often attached to rocks and other seaweeds and is also found floating. We are also looking into preferred materials where we grow them, do we want them floating or settled, that is also quite decisive for how the future farms will look,” says Johan. Once the team determines suitable conditions to do this, they should be able to take the brood stock out of fridge storage and start to produce adults as required. At that stage they will be able to start pilot scale studies using facilities at the Institute’s Aquaculture Park. 

Nobody in the world yet is growing Asparagopsis on a large scale. Some countries, notably in Asia, are growing large kelp species in bulk but Asparagopsis is much smaller and requires different conditions. “There are challenges in growing it on land and the sea, but it doesn’t make sense to use arable land for aquaculture, and with the fourth largest economic zone in the seascape around us there is plenty of ocean for us to use,” Johan says.

The Cawthron Institute is receiving $100,000 from the Government’s Sustainable Food & Fibre Futures fund through the Ministry for Primary Industries (MPI) for the Asparagopsis research over the year-long project. Cawthron itself is contributing $150,000. 

Last year the Institute was also granted $6 million from the Government’s Provincial Growth Fund to build a national algae research centre, which is currently under construction. CEO Prof. Charlie Eason says the new facility will help expand, develop and support New Zealand’s fledgling algae sector. 

“Algae have uses across a broad spectrum including improved feeds for shellfish, feed additives for cattle, cosmetics, nutraceuticals and pharmaceuticals. Aquaculture in general is the fastest growing primary sector globally, and the micro-algae and seaweed industries are at the early stage of development,” he says. 

“Clearly we have made considerable progress in shellfish aquaculture and in hatcheries for Pacific oysters and for green-shell mussels, so the impact of the research process is proven in determining how to breed and grow material whether it's shellfish or algae.”

“We don’t want to go out and just harvest wild species until there is none left, which is what has happened in the past.  Instead we need to work out the breeding systems for high-value seaweeds and figure out how best to produce them. Then we’ll be in keeping with the New Zealand philosophy of producing high-quality primary sector products, rather than just bulk.” 

The new algae research facility is at the design and planning phase, and Prof. Eason hopes it will be completed early next year. Cawthron currently houses the national micro-algae culture collection containing 300 strains of micro-algae and cyanobacteria. “These are very important for our understanding of algae. As well as creating opportunities, algae can be harmful if found in our shellfish, so we have in place a really good monitoring system that Cawthron leads alongside MPI,” Charlie says. 

“There are many more opportunities for algae, and the Asparagopsis project is a good example of that. There is also potential for algae to produce drugs because large proportion of drugs are inspired by natural products, so we are involved in producing extracts that go into trials.” 

“Some of these are of ultrahigh value because the drugs that we are producing require minuscule doses and sell for around $1 million for the equivalent of one aspirin tablet, so there is potential to increase that kind of return as well as high value from seaweed and other algae. That's what we want to help New Zealand industry to move towards.”

Showdown Productions Ltd – Rural Delivery Series 15 2020