Australia-listed BPH Global has reported exceptional gold and copper assay results from its seaweed cultivation research, validating the potential of marine plants to absorb valuable minerals from seawater.

The latest assays, conducted by Temasek Innovation Holdings (TPIH) in Singapore in collaboration with Gaia Mariculture, revealed gold concentrations of up to 14.85 mg/kg and copper concentrations of up to 10.88 mg/kg in seaweed cultivated in clean, filtered seawater from the island of Sentosa.

“The presence of gold and copper, in addition to the previously identified cobalt and silver, marks another exciting milestone in our research,” said MD Matthew Leonard. “These results further support our view that seaweed has the potential to act like a sponge for base and precious metals in seawater. We look forward to investigating this further in Phase 2 of the R&D programme.”

Phase 1 of BPH Global’s research programme focused on growing sesuvium portucalastrum seaweed in a controlled laboratory environment, using water free from industrial or urban pollution. Initial assays confirmed significant levels of silver and cobalt, prompting additional testing for gold and copper.

Samples were analysed using inductively coupled plasma–mass spectrometry (ICP-MS) after processing with concentrated nitric acid and hydrogen peroxide. The results indicated that this particular seaweed species is highly efficient at mineral absorption, reinforcing its potential application in environmental remediation and resource recovery.

Building on these findings, BPH Global will now expand its research to investigate mineral absorption in more challenging environments. Phase 2 will involve cultivating sesuvium portucalastrum in the brackish waters of Johor, Malaysia, an area exposed to industrial activity and shipping traffic.

This next phase aims to test the hypothesis that seaweed grown in polluted water absorbs higher concentrations of minerals due to the ‘sponge’ effect, potentially making it a viable tool for both environmental clean-up and resource extraction.