A potential solution to methane emissions produced by Ireland’s livestock sector could be growing under our noses – and under the sea, off the Irish coast.
A species of red seaweed called Asparagopsis Armata has the potential to cut methane emissions in cattle by up to 98% – and the structure is already in place for seaweed farms to produce it relatively quickly, should research trials be successful.
Speaking to Agriland, Dr. Julie Maguire, research director of Bantry Marine Research Station, explained that this plant is at the centre of a study she is conducting, noting that the project has evolved towards finding out the life cycle of the plant, and how to farm it:
“The study is funded by Bord Iascaigh Mhara [BIM]. They funded this study about a year ago. First we screened loads of different seaweed to see if it had this active ingredient for methane reduction which is called bromoform.”
Noting that, in various studies carried out internationally to date, asparagopsis came up time and time again as having this compound in spades, Dr. Maguire added:
“It has 400 times more than the next highest species. All seaweed species have this ingredient but this [asparagopsis] was head and shoulders above the rest.”
Cork seaweed
Noting that original trials investigated an Australian breed of the asparagopsis plant called Asparagopsis Taxiformis, which grows in tropical waters, a breed growing in temperate waters called Asparagopsis Armata was found growing off the Cork coast.
“It’s native to Ireland; it’s native along the Atlantic coast of Europe and in the Mediterranean as well,” the marine biologist noted, adding that it likes warm water and is essentially a summer species.
“This year, BIM gave us another study on trying to grow it. It would be very hard to harvest it in the wild because it likes to grow in amongst other seaweeds,” she explained, adding that it is also similar to other species – and in some cases impossible to tell apart with the naked eye.
Cow’s rumen
In terms of its effectiveness, Dr. Maguire said, when fed in small quantities to cattle, the bromoform changes the microbiome in the rumen.
This stops the production of methane, instead producing water and hydrogen.
“In the studies we’ve read, it’s up to 98% reduction, some of them really high,” the research director added.
“You could add it directly, sprinkle it or throw it out in a field – you only need a tiny amount – or automatically put into your bales or into calf nuts or cows’ licks.”
Noting that the team has received a lot of interest from animal feed businesses about exploring this area, she said:
“We know what we’re good at – the marine biology side and growing the plant. We’d love for someone else to take on [the animal supplement] side of things.
“We just want to work out how it grows and then ramp up the biomass,” she explained.
Growing asparagopsis
Furthermore, if this can be established, there may already be the structure in place to speedily develop a sector to grow asparagopsis.
As things stand, there are approximately 230ha of seaweed farms licenced in Ireland, growing predominantly kelp, in what is a growing sector.
Dr. Maguire noted that, at Bantry Marine Research Station, there are currently two kelp farms.
“For kelp farmers, we put our lines out in November and we harvest in March or April; then the farm is empty until next November.
“Our site in Bantry is empty at the moment because that’s just the growing cycle of the kelp. During the summer all of these farm sites are empty – and asparagopsis is a summer species.
“If the Department of Agriculture [granted aquaculture licences], it’d be relatively easy to switch to asparagopsis because the sites are already there and are not being used during the summer for the most part.”
In addition, asparagopsis “can’t get enough of nutrients” which would make it an ideal biofilter, as Dr. Maguire explained:
“It’s absolutely brilliant at absorbing CO2 as well. It’s kind of a double whammy on the greenhouse gases [GHG].
“CO2 is the common greenhouse gas that everyone talks about, but methane is so much more potent than CO2 and it’s a big problem for us and the farmers.
“I grew up on a dairy farm; my brother is a farmer and so is my brother-in-law; we’ve one side of the family where everyone’s a farmer.
“That’s the big worry they all have. It’s nothing that they’ve done; it’s just biology. The cattle can’t help it. But to me anyway, it sounds like a no-brainer; the seaweed is natural.”
Lowering emissions
Outlining her belief that this could be a key tool in the effort to lower livestock emissions, Dr. Maguire noted that her team has received international interest as well.
The life cycle of the asparagopsis plant itself sees two life stages – the first form the plant takes gives the appearance of a “pompom” fluffy ball; the second is a more traditional-looking gametophyte plant form, that produces seeds.
At present, Bantry Marine Research Station is seeking to find out “what makes it tick” in terms of optimal light conditions, nutrients, temperatures, etc.
“Once we crack the life cycle and how it’s grown, then it’s very easy to copy.
“There’s no reason why we couldn’t produce a lot of biomass quickly, because we have all those sites as well.
“There are the farmers in place already and most seaweed farmers will grow a species so long as there’s a market for it,” the marine biologist concluded.