The abundance of sargassum—an invasive brown macroalga that has proliferated for more than ten years on the coasts of the Tropical Atlantic—is altering environmental conditions and harming marine species in the lagoons and reefs of the Caribbean in Mexico.
However, scientists in the area are developing projects to turn its presence into a valuable resource that helps reduce pollution.
A study published in Science of the Total Environment analyzed the levels of exposure to sargassum during the period 2015-2021. This study determined that the massive arrival of this marine species causes hypoxia—oxygen deficit—and “deteriorates water quality in coastal areas.”
The authors warn that “the arrivals of abundant sargassum threaten the ecosystem’s stability.”
This massive presence generates an adverse environmental effect, as macroalgae block the passage of light, cause chemical changes in the water, and harm marine flora and fauna. Additionally, it brings socioeconomic consequences, such as a decline in tourism, the paralysis of real estate markets, and high costs associated with its removal.
Diego Lizcano, a biologist at the University of Los Andes (Bogotá) and one of the authors of the work, detailed to SciDev.Net that when sargassum begins its decomposition process, it “reduces water quality and harms corals, as well as all marine life.” He was emphatic in stating: “Where sargassum accumulates, oxygen decreases.”
“From 2021 onwards, the problem of sargassum abundance has worsened and is very likely to continue to worsen. There is no simple solution to this issue,” he indicated. “Efforts to clean it from the beaches are ineffective, as the situation is identical to the previous day the next day,” he lamented.
According to the Sargassum Watch System, operated by the University of South Florida, during the year 2025, an accumulation of over 31 million metric tons of sargassum abundance was recorded in the Atlantic Ocean.
Scientists claim that this phenomenon is directly linked to climate change, due to the increase in nutrients in the water, the rise in temperature, and changes in climatic patterns.
In Lizcano’s opinion, the enormous masses of sargassum are severely affecting the region. “This has caused visitors to avoid the Mexican Caribbean beaches, which generates serious economic difficulties, as numerous communities and cities depend on tourism. People refuse to bathe on those beaches,” he commented.
From a crisis to an opportunity
For years, various research teams in the region have been developing initiatives to process sargassum and use its biomass in the manufacture of bioplastics, fertilizers, cosmetic products, and biofuels.
“It would be possible to transition from a crisis to an established industry,” Iván Ehcatl López González, a Biosciences engineer from the Autonomous University of the State of Hidalgo (Mexico), told SciDev.Net. López González is co-author of the study The invasion of sargassum: from an environmental problem to an area of opportunity, which highlights the potential production of biofuels (such as bioethanol, biogas, and biodiesel) derived from sargassum, in addition to other products and materials.
According to López González, “it has been possible to obtain cosmetics, pharmaceuticals, bioplastics, construction materials, and paper.” He assured that “the range of products available that can be obtained from sargassum is very extensive, depending on how the biomass is used and the progress of technology and research.”
However, he was cautious regarding biofuels, clarifying that although “good yields were achieved,” from an economic viability standpoint, “it may be more profitable to obtain products with greater commercial output, such as cosmetics.”
“The energy field of sargassum has potential, but it requires considerable research and there are still no established plants or biorefineries,” he stated.
The engineer detailed that, in contrast to other biomasses, “the advantage is that it does not compete with food resources nor does it require agricultural land, as it floats massively and is available almost all year round.”
In any case, he emphasized that there are still numerous challenges for the production of biofuels, due to its high saline content, the presence of significant amounts of heavy metals, and other compounds that make the processing of sargassum difficult.
According to Lizcano, “it is very positive that sargassum can be used in economic activities” such as biofuels, cosmetics, and bioplastics, as this “could help mitigate the cycle of global warming.”
The challenges posed by sargassum
Argentine biologist Paula Raffo, an expert in brown algae and a researcher at Conicet at the Center for the Study of Marine Systems, agreed on the potential offered by sargassum for the creation of biomaterials.
Raffo, who was not part of the study, told SciDev.Net that “it represents an interesting alternative for the manufacture of paper, cardboards, and single-use plastics.” Regarding biofuels, she noted that more research and the development of appropriate technologies are still needed.
“The range of products available that can be obtained from sargassum is very extensive, depending on how the biomass is used and the progress of technology and research.” — Iván Ehcatl López González, Biosciences engineer from the Autonomous University of the State of Hidalgo, Mexico.
“In terms of plastics, which are the main cause of ocean pollution, it could be a good substitute, and there is enough biomass,” she indicated. “Although sargassum is an invasive species, it offers utilization alternatives and is a friendly option to replace certain polluting sources. Although it is difficult to estimate the amount of algae, through satellite images it would be possible to map and calculate the surface of available biomass,” she stated.
The absence of regulations governing the collection, transportation, exploitation, and business models also represents a challenge.
Abundance of sargassum: from agriculture to clean energy
Additional research is exploring the potential of sargassum to be used as an input in agriculture and energy. An article published in Phycology noted that extracts from this macroalga have the ability to optimize the germination and development of crops such as corn, tomatoes, and peppers, thanks to the enrichment of the soil with natural nutrients.
Simultaneously, scientists in Mexico are working on the manufacture of supercapacitors (devices that can store energy quickly and efficiently, increasingly used in portable electronic devices and renewable energy systems).
To do this, they use the abundance of sargassum as raw material, seeking to transform this marine plague into a sustainable alternative, with the goal of “turning marine waste into a functional material,” according to their study published in the Journal of Materials Science.
Despite this, there are still numerous challenges: the fluctuation in the amount of available biomass and the need to optimize performance. Added to this are logistical obstacles and the lack of regulatory frameworks that allow its sustainable use.
Source: Agustín Gulman/SciDev.Net
