MONTREAL -- Researchers from Quebec and China have highlighted the unexpected benefits of aluminum when it comes to trapping carbon dioxide (CO2) at the bottom of the ocean.
Researchers are looking at phytoplankton, which lives in the ocean, as a potential ally to fighting climate change underwater.
Similar to trees on the Earth's surface, these algae capture CO2, one of the greenhouse gases responsible for global warming, and release oxygen.
The study is the result of a collaboration between researchers at the Institut national de la recherche scientifique (INRS) in Quebec and Chinese colleagues, who approached them after obtaining promising results.
Linbin Zhou, the first author of the study, which was published last month, pursued his work in Quebec with other researchers from China, as well as professor-researchers Claude Fortin and Peter Campbell, the latter being a leading expert in geochemistry and aquatic ecotoxicology.
"I was a bit skeptical at first," said Fortin, who specializes in the biochemistry of metals, in an interview with The Canadian Press. "But I found it intriguing."
He explains that aluminum had always been considered a non-essential element of life, one that was harmful even, so the idea that it could play a positive role in the environment did not initially make sense.
Together, the researchers designed several scientific experiments at the INRS's Centre Eau Terre et Environnement to test their hypotheses by subjecting algae to different concentrations of aluminum dissolved in water.
Their results suggest that aluminum plays two roles: it promotes the growth of phytoplankton that assimilate CO2 and it also "significantly" delays the degradation of algae -- sometimes by more than 50 per cent -- thus slowing the release of carbon dioxide.
"Aluminium could then contribute to improving CO2 sequestration," summarized Fortin, adding the element is found naturally in marine waters and is not the result of waste dumped in the ocean, such as soft drink cans.
Aluminum is among the most abundant elements in the Earth's crust.
"This discovery does not offer any concrete action or industrial solution," Fortin admitted, but it does provide an understanding of aluminum's role in carbon dioxide sequestration, furthering our understanding of a natural phenomenon that benefits the planet.
According to the researchers, these results could also have an impact on climate models by integrating the "positive" effects of aluminum in the deep ocean.
This study, which is the result of work carried out by professors Tan Yehui and Linbin Zhou, of the South China Sea Institute of Oceanology (SCSIO) with the Chinese Academy of Science, and professors Campbell and Fortin of the INRS, was published in May in the scientific journal Limnology and Oceanography.
-- This report by The Canadian Press was first published in French on June 8, 2021.
