Limu Kohu | |
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Asparagopsis taxiformis in Mayotte. | |
Scientific classification | |
(unranked): | Archaeplastida |
Division: | Rhodophyta |
Class: | Florideophyceae |
Order: | Bonnemaisoniales |
Family: | Bonnemaisoniaceae |
Genus: | Asparagopsis |
Species: | A. taxiformis |
Binomial name | |
Asparagopsis taxiformis | |
Synonyms | |
Asparagopsis sanfordiana |
Asparagopsis taxiformis (red sea plume or limu kohu), formerly A. sanfordiana, [1] is a species of red algae, with cosmopolitan distribution in tropical to warm temperate waters. [2] Researchers have demonstrated that feeding ruminants a diet containing 0.2% A. taxiformis seaweed reduced their methane emissions by nearly 99 percent. [3]
Like many red algae, A. taxiformis has a haplodiplophasic lifecycle, with each phase morphologically distinct. The species' diploid stage was initially described as Falkenbergiahillebrandii(Bornet) Falkenberg 1901 because it was thought to be a separate species.
Asparagopsis is one of the most popular types of limu. [4] in the cuisine of Hawaii, it is principally a condiment. [5] It is known as Limu kohu in the Hawaiian language, meaning "pleasing seaweed". [6] Limu kohu has a bitter taste, somewhat reminiscent of iodine, [7] and is a traditional ingredient in poke.
The essential oil of limu kohu is 80% bromoform (tri-bromo-methane) by weight. [8] It also includes many other bromine- and iodine-containing organic compounds. [5]
In 2014, researchers at CSIRO and James Cook University (supported by Meat & Livestock Australia) demonstrated that treating ruminal fluid with one to two percent red seaweed reduced their methane emissions by over 90 percent. [9] Of 30 types of seaweed tested, A. taxiformis showed the most promise, with nearly 99 percent effectiveness. [10]
The findings spurred further investigation into its effects on ruminant animal enteric methane production. In 2016, the same team showed that 2-5% of seaweed biomass effectively reduced production by 98-100% [11] in vitro and, in a separate study, identified the bioactives in A. taxiformis. While dichloromethane extract was the most potent bioactive, reducing methane production by 79%, bromoform and dibromochloromethane had the highest activity inhibiting methane production, and only bromoform is present in sufficient quantities to be effective. [12] In 2020, they showed that a 0.2% addition of A. taxiformis to cattle’s feed reduced the livestock’s methane emissions by over 98%. [13] In 2021, a team from UC Davis found that additions of 0.25% and 0.5% reduced cattle’s enteric methane emissions by 69.8% and 80% respectively. [14]
Supply from wild harvest is not expected to be adequate to support broad adoption. Subsequent to the Australian study, CSIRO established FutureFeed Pty Ltd., which holds the global intellectual property (IP) rights for the use of Asparagopsis for livestock feed, with the aim of significantly reducing enteric methane emissions in ruminants. [15] In 2020, FutureFeed won a Food Planet Prize worth USD $1 million for the research behind its inception. [16]
A. taxiformis has yet to be commercially farmed at scale, but several companies are working towards it as they make the seaweed available to the livestock industry. A research/development initiative called Greener Grazing is seeking to close the life cycle of A. taxiformis and demonstrate ocean-based grow-out. [17] A startup out of KTH Royal Institute of Technology, Volta Greentech, Sea Forest, SeaStock, Immersion Group, Synergraze, Symbrosia and Blue Ocean Barns, are growing A. taxiformis in vertical, near-shore land-based tanks, using seawater to provide the proper temperature and nutrients. [18] [19] Symbrosia, from Yale University, is looking to integrate the cultivation with whiteleg shrimp on land, using a patent-pending technology. [20] Another start-up, CH4 Global, has developed energy-efficient EcoParks in Australia and New Zealand to produce A. taxiformis for use in its solutions for feedlot cattle. [21] CH4 Global has partnered with Clean Seas to grow A. taxiformis at Arno Bay, Australia, where it uses carbon and nitrogen waste from Clean Seas’ ocean-based fish farms as food for the seaweed. [22] In 2023 CH4 global reported its first commercial sale and intentions to feed the additive to 10,000 cattle. [23]
Volta Greentech, Blue Ocean Barns, Symbrosia and CH4 Global have been backed by venture capital funds.
Dichloromethane is an organochlorine compound with the formula CH2Cl2. This colorless, volatile liquid with a chloroform-like, sweet odor is widely used as a solvent. Although it is not miscible with water, it is slightly polar, and miscible with many organic solvents.
Fodder, also called provender, is any agricultural foodstuff used specifically to feed domesticated livestock, such as cattle, rabbits, sheep, horses, chickens and pigs. "Fodder" refers particularly to food given to the animals, rather than that which they forage for themselves. Fodder includes hay, straw, silage, compressed and pelleted feeds, oils and mixed rations, and sprouted grains and legumes. Most animal feed is from plants, but some manufacturers add ingredients to processed feeds that are of animal origin.
Burping is the release of gas from the upper digestive tract of animals through the mouth. It is usually audible.
Bromoform is an organic compound with the chemical formula CHBr3. It is a colorless liquid at room temperature, with a high refractive index and a very high density. Its sweet odor is similar to that of chloroform. It is one of the four haloforms, the others being fluoroform, chloroform, and iodoform. It is a brominated organic solvent. Currently its main use is as a laboratory reagent. It is very slightly soluble in water and is miscible with alcohol, benzene, chloroform, ether, petroleum ether, acetone and oils.
Enteric fermentation is a digestive process by which carbohydrates are broken down by microorganisms into simple molecules for absorption into the bloodstream of an animal. Because of human agricultural reliance in many parts of the world on animals which digest by enteric fermentation, it is the second largest anthropogenic factor for the increase in methane emissions directly after fossil fuel use.
Dibromochloromethane is a colorless to yellow, heavy and nonflammable compound with formula CHBr
2Cl. It is a trihalomethane. The substance has a sweet odour. Small quantities of dibromochloromethane are produced in ocean by algae.
Mastocarpus stellatus, commonly known as carrageenan moss or false Irish moss, is a species in the Rhodophyceae division, a red algae seaweed division, and the Phyllophoracea family. M. stellatus is closely related to Irish Moss. It grows in the intertidal zone. It is most collected in North Atlantic regions such as Ireland and Scotland, together with Irish moss, dried, and sold for cooking and as the basis for a drink reputed to ward off colds and flu. Marine biologists have completed studies on the medicinal reputation of M. stellatus to discover the full potential of its pharmaceutical benefits. Additionally, marine biologists have conducted research on its potential to serve as an alternative to plastic. The application of M. stellatus in these different industries is correlated with the seaweed's adaptations which developed in response to the environmental stressors present around its location on the rocky intertidal.
Caulerpa lentillifera or sea grape is a species of ulvophyte green algae from coastal regions in the Asia-Pacific. This seaweed is one of the favored species of edible Caulerpa due to its soft and succulent texture. It is traditionally eaten in the cuisines of Southeast Asia, Oceania, and East Asia. It was first commercially cultivated in the Philippines in the 1950s, followed by Japan in 1968. Both countries remain the top consumers of C. lentillifera. Its cultivation has since spread to other countries, including Vietnam, Taiwan, and China. C. lentillifera, along with C. racemosa, are also known as sea grapes or green caviar in English.
Methane is a chemical compound with the chemical formula CH4. It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it is hard because it is a gas at standard temperature and pressure.
Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of Rhodophyta (red), Phaeophyta (brown) and Chlorophyta (green) macroalgae. Seaweed species such as kelps provide essential nursery habitat for fisheries and other marine species and thus protect food sources; other species, such as planktonic algae, play a vital role in capturing carbon and producing at least 50% of Earth's oxygen.
Organobromine chemistry is the study of the synthesis and properties of organobromine compounds, also called organobromides, which are organic compounds that contain carbon bonded to bromine. The most pervasive is the naturally produced bromomethane.
Asparagopsis armata is a species of marine red algae, in the family Bonnemaisoniaceae. English name(s) include red harpoon weed. They are multicellular eukaryotic organisms. This species was first described in 1855 by Harvey, an Irish botanist who found the algae on the Western Australian coast. A. armata usually develops on infralittoral rocky bottoms around the seawater surface to around 40m of depth. Marine algae like A. armata are considered "autogenic ecosystem engineers" as they are at the very bottom of the food chain and control resource availability to other organisms in the ecosystem.
Edible seaweed, or sea vegetables, are seaweeds that can be eaten and used for culinary purposes. They typically contain high amounts of fiber. They may belong to one of several groups of multicellular algae: the red algae, green algae, and brown algae. Seaweeds are also harvested or cultivated for the extraction of polysaccharides such as alginate, agar and carrageenan, gelatinous substances collectively known as hydrocolloids or phycocolloids. Hydrocolloids have attained commercial significance, especially in food production as food additives. The food industry exploits the gelling, water-retention, emulsifying and other physical properties of these hydrocolloids.
Meat & Livestock Australia (M&LA) is an independent company which regulates standards for meat and livestock management in Australian and international markets. Headquartered in North Sydney, Australia; M&LA works closely with the Australian government, and the meat and livestock industries. M&LA has numerous roles across the financial, public and research sectors. The M&LA corporate group conducts research and offers marketing services to meat producers, government bodies and market analysts alike. Forums and events are also run by M&LA aim to provide producers with the opportunity to engage with other participants in the supply chain.
Asparagopsis is a genus of edible red macroalgae (Rhodophyta). The species Asparagopsis taxiformis is found throughout the tropical and subtropical regions, while Asparagopsis armata is found in warm temperate regions. Both species are highly invasive, and have colonised the Mediterranean Sea. A third accepted species is A. svedelii, while others are of uncertain status.
Increasing methane emissions are a major contributor to the rising concentration of greenhouse gases in Earth's atmosphere, and are responsible for up to one-third of near-term global heating. During 2019, about 60% of methane released globally was from human activities, while natural sources contributed about 40%. Reducing methane emissions by capturing and utilizing the gas can produce simultaneous environmental and economic benefits.
Dictyota is a genus of brown seaweed in the family Dictyotaceae. Species are predominantly found in tropical and subtropical seas, and are known to contain numerous chemicals (diterpenes) which have potential medicinal value. As at the end of 2017, some 237 different diterpenes had been identified from across the genus.
FutureFeed was established by Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO), FutureFeed holds the global intellectual property for the use of Asparagopsis seaweed as a ruminant livestock feed ingredient that can reduce methane emissions by 80% or more. This result can be achieved by the addition of a small amount of the seaweed into the daily diet of livestock. This discovery was made by a team of scientists from CSIRO and James Cook University (JCU), supported by Meat & Livestock Australia (MLA), who came together in 2013 to investigate the methane reduction potential of various native Australian seaweeds.
The amount of greenhouse gas emissions from agriculture is significant: The agriculture, forestry and land use sector contribute between 13% and 21% of global greenhouse gas emissions. Agriculture contributes towards climate change through direct greenhouse gas emissions and by the conversion of non-agricultural land such as forests into agricultural land. Emissions of nitrous oxide and methane make up over half of total greenhouse gas emission from agriculture. Animal husbandry is a major source of greenhouse gas emissions.
Jennifer E. Smith is an American marine ecologist and coral reef expert who works at the Scripps Institution of Oceanography. Her research investigates how physical and biological processes impact the function of marine communities.