Researchers have been working to trace and research floating sargassum, a prolific seaweed swamping Caribbean and West African shorelines, and inflicting environmental and financial hurt.
The stranded seaweed blocks fishing boats; threatens tourism; disrupts turtle nesting websites, reefs and mangroves, and releases poisonous gasoline, which impacts human well being and damages electrical tools.
First reported by Christopher Columbus within the fifteenth century, floating mats of sargassum have lengthy been current within the North Atlantic. Nonetheless, since 2011, a floating inhabitants has established between West Africa and South America, and elevated in dimension to type “the good Atlantic sargassum belt” – a 9,000km-long macroalgal bloom, seen from area and estimated to weigh 35 million tons.
The huge blooms of sargassum are regarded as right down to nutrient air pollution and warming seas, and huge portions of the seaweed find yourself in landfill every year.
The analysis staff, from the Universities of York and Southampton, alongside colleagues from the College of the West Indies in Jamaica and Barbados, got down to be taught extra about sargassum’s biomass composition as a way to unlock its potential for use to supply sustainable merchandise.
Whereas the seaweed is an plentiful biomass, its potential makes use of are restricted because of its excessive arsenic content material.
First writer of the research Dr Carla Machado, a analysis affiliate within the Division of Biology, mentioned: “The small portions of sargassum that used to scrub ashore within the Caribbean supplied a habitat for turtles, crabs and fish and contributed to seaside formation because it decomposed, however the huge sargassum blooms of the previous decade are a world drawback that can proceed to develop and have a significant affect within the affected international locations.
This analysis mission has introduced collectively worldwide researchers specialising in biomass composition and satellite tv for pc imaging to trace, pattern and research sargassum, offering essential new data of this little-understood macroalgae.”
For a biomass to be utilised, it must be constant in its composition; this ensures it may be processed effectively and behave predictably throughout manufacturing.
The outcomes of the research confirmed that, total, the biochemical composition of sargassum is constant all year long. The researchers examined totally different processing strategies for the seaweed, together with shade-drying or freezing, and located the protein content material of the seaweed stayed the identical. Nonetheless, the strategy of processing did have an effect on ranges of different parts equivalent to alginate, which could be processed for a lot of purposes, together with biomaterials.
The researchers collected samples of sargassum in Jamaica all through 2021, which coincided with the April 2021 eruption of La Soufrière on the Caribbean island of Saint Vincent.
Utilizing drift patterns, the authors calculated that the sargassum samples they collected in August 2021 would have spent roughly 50 days uncovered to ash from the eruption.
They discovered that seaweed that had doubtless been in touch with volcanic ash contained much less arsenic, however had collected different parts together with nickel and zinc.
Lead writer of the research, Dr Thierry Tonon from the Division of Biology on the College of York mentioned: “Understanding sargassum’s response to environmental situations is essential for unlocking its biology and potential worth.
“With the good sargassum belt additionally receiving further vitamins from Sahara mud that blows throughout the Atlantic, large portions of the seaweed washing up on coastlines appears to be like set to grow to be the brand new regular.”
There may be far more work to be finished to extend understanding about sargassum and the way it’s going to behave in years to come back, the researchers say. This can present a physique of proof that would inform a world response to the issues it poses to individuals and the atmosphere and rework it into one thing helpful.
Professor Robert Marsh from the College of Southampton mentioned: “The sargassum beaching round Jamaica in late summer time 2021 carried distinct traces of the volcanic ash that settled upon it round 4 months earlier, simply to the east of St Vincent; this novel ‘volcanic tag’ confirmed that sargassum arrives every summer time at Jamaican seashores after a months-long journey drifting with currents from the central tropical Atlantic.”
Professor Hazel A. Oxenford from the College of the West Indies mentioned: “Volcanic ash collected in my backyard from the St Vincent eruption was used to find out its chemical signature. Having the ability to detect these parts in sargassum after it travelled greater than 1,700 km throughout the Caribbean to Jamaica was thrilling. It confirmed our predicted transport pathway for sargassum, confirmed that the seaweed lives for at the least 4 months and demonstrates the marine connectivity throughout the area.”
Professor Mona Webber from the College of the West Indies added: “It is vitally necessary for Caribbean Islands being affected by the sargassum inundation to have the ability to profit from its valorization. Understanding how the sargassum we acquire in Jamaica has modified en path to our shores and elements that would have an effect on particularly the arsenic content material, will propel us in the direction of protected use of the algal biomass.”
