A research team led by the University of Alaska Fairbanks has been awarded a $1.9m federal grant to explore whether Southeast Alaskan seaweed is absorbing rare earths.
The study will look at Alaskan seaweed near Bokan Mountain, a remote landmark on Prince of Wales Island known to contain rare earths.
The team will begin collecting and analysing seaweed samples in March 2024 to learn whether a large amount of the metals that were washed into the ocean are being absorbed.
Lead researcher Schery Umanzor, an assistant professor of marine biology at UAF’s College of Fisheries and Ocean Sciences, said: “We want to see if seaweeds accumulate rare earth elements at a concentration that makes sense financially to recover them.
“Seaweeds must act as sponges, with the elements showing up in higher concentrations than that in the water.”
The project is funded by the U.S. Department of Energy.
Expanding the US’ supply of rare earths
The project is part of a larger effort of the US to expand their domestic supply of rare earths.
Metals are important components of renewable energy technologies. Currently, the majority of rare earths are sourced from sites in China.
Seaweeds can absorb REEs
Preliminary assessments have indicated that seaweed can absorb rare earths, but it is unknown what concentrations the metals exist and how difficult it would be to extract them.
The study will first focus on wild stocks of seaweed and the amounts of the metals that will be collected in their tissues.
If the results are promising, a second phase will focus on the potential for seaweed farms to gather rare earths, such as variations among types of algae and growing conditions.
The potential of extraction from seaweed
Extracting REEs from seaweed needs to be part of a large commercial food operation to be successful. This is because high accumulations would only yield a few dollars’ worth of metals per ton of seaweed.
If found to be viable, however, seaweed has the potential to be a low-impact alternative to mining.
Umanzor said: “It has tremendous potential, but it has to be to scale.
“A mom-and-pop farm is not going to work.”
