Caribbean islands have seen their coastlines blanketed with Sargassum seaweed, every year since 2011. The phenomenon has posed significant challenges for the fishing and tourism sectors. Countries attempt to remedy the problem by raking the Sargassum and disposing of it in landfills, especially before it decomposes. However, this is a very expensive venture, estimated to cost some US$210 million in 2018.

Yet, if the current commercial application of other brown algae is anything to go by, Sargassum seaweed may have the potential to be transformed into other useful material. Some potential uses being explored include bioremediation, as texturing agents for the food industry, as nutraceuticals, biofuels, fertilisers, animal feed, and cosmeceuticals.

In a study recently published in Science of the Total Environment, researchers from the Department of Chemistry, The UWI – Doleasha Davis, Sanjay Campbell, Melissa Marston, and Winklet Gallimore – along with colleagues from the University of York, in the United Kingdom, explore the composition of the Sargassum seaweeds found in the Caribbean in an attempt to inform potential valorisation pathways.

The researchers undertook a detailed biochemical and elemental analysis of three types of pelagic Sargassum and highlighted similarities and differences among the Sargassum seaweed types which they suggest can serve as a guide for potential future usage. In general, the relatively high arsenic content of the pelagic Sargassum limits its potential use for nutritional purposes. Relatively low yields of alginate, compared with brown algae further limit their use as a viable source of commercial alginates. Alginates have several industrial applications including, for example, as an ingredient in various pharmaceutical preparations. 

Importantly, the study suggests the need for even more research to ensure safe usage of the Sargassum seaweed in any future by-products.