Heavy Metal Pollution Decreasing in Brown Algae

Heavy Metal

A global decrease in heavy metal concentrations in brown algae has become apparent over the last 50 years.

In the current scenario of global change, heavy metal pollution is of major concern because of its associated toxic effects and the persistence of these pollutants in the environment. A new study is the first to evaluate the changes in heavy metal concentrations worldwide in brown algae over the last 90 years (>15,700 data across the globe reported from 1933 to 2020).

The study findings revealed significant decreases in the concentrations of Cd, Co, Cr, Cu, Fe, Hg, Mn, Pb and Zn of around 60–84% (ca. 2% annual) in brown algae tissues. The decreases were consistent across the different families considered (Dictyotaceae, Fucaceae, Laminariaceae, Sargassaceae and others), and began between 1970 and 1990. In addition, strong relationships were detected between these trends and pH, SST, and heat content.

Although the observed metal declines could be partially explained by these strong correlations, or by adaptations in the algae, other evidence suggests an actual reduction in metal concentrations in oceans because of the implementation of environmental policies.

In any case, this study shows a reduction in metal concentrations in brown algae over the last 50 years, which is important in and of itself as brown algae form the basis of many marine food webs and are therefore potential distributors of pollutants.

Credit: Aboal J. R., Pacín C., García-Seoane R., Varela Z., González A. G. & Fernández J. A., 2023. Global decrease in heavy metal concentrations in brown algae in the last 90 years. Journal of Hazardous Materials 445: 130511. doi: 10.1016/j.jhazmat.2022.130511. Article (subscription required)

Information provided by: Ocean Acidification International Coordination

All rights reserved. Permission required to reprint articles in their entirety. Must include copyright statement and live hyperlinks. Contact david@algaeplanet.com. Algae Planet accepts unsolicited manuscripts for consideration, and takes no responsibility for the validity of claims made in submitted editorial.

Seagriculture EU 2024


EABA AlgaeEurope23
Hire Robin Coles Technical Writer


  • November 27, 2023: Australia’s first high-level organization to serve the commercial seaweed industry officially launched in Canberra on November 16, 2023. The Australian Sustainable Seaweed Alliance (ASSA) represents ten corporate members across six states and was launched to advance environmentally responsible farming and production, strategic research and development, and scientific and biotech-related commercialization. READ MORE...
  • November 20, 2023: A research team from IIT Gandhinagar, a leading technical institution in India, has found that beads made from a combination of sea algae, salt, and nanoparticles can be used to remove dyes from wastewater pollution created in the dye and chemical industries. READ MORE...
  • November 17, 2023: Isis Central Sugar Mill, 300km north of Brisbane, Australia, will soon be home to ponds growing algae fed by the mill’s wastewater. The mill will harvest the carbon dioxide created when they burn fiber left over from crushing cane to make electricity and use the nutrients in the wastewater to feed the algae, which is intended for food and fuel. READ MORE...

A Beginner’s Guide