Along Phang-Nga Bay, most sediment metals were bound to crystalline phases and therefore appeared to have low bioavailability, but the potentially mobile fractions of Zn, Ni, and Cd averaged above 10%, indicating medium risk. Enhalus acoroides accumulated Cd, Zn, and Cu efficiently and preferentially translocated metals to leaves rather than rhizome-root tissues.
Key findings
- Most metals except Zn were associated with crystalline phases, suggesting low bioavailability under the sampled conditions. Mean risk assessment codes for Zn, Ni, and Cd exceeded 10%, classified by the authors as medium risk. Mean translocation factors exceeded 1 for all metals, indicating greater leaf accumulation, while bioconcentration factors supported strong sequestration of Cd, Zn, and Cu.
Why this matters globally
Seagrass meadows support biodiversity and blue carbon while receiving coastal contaminants. Assessing metal speciation rather than total concentration alone can make ecological surveillance and risk prioritisation more informative.
Thai researcher contribution
Researchers from Prince of Songkla University, Chulalongkorn University, the Department of Marine and Coastal Resources, and Suratthani Rajabhat University generated evidence from a Thai coastal ecosystem. Publisher metadata places Danai Tipmanee at Prince of Songkla University, correcting an automated institution-name mismatch in a secondary database.
Limitations to consider
The abstract does not report station count, seasonality, concentration ranges, or pollutant sources, so natural and anthropogenic contributions cannot be separated. Tissue metals do not by themselves establish toxicity or consumer risk, and Phang-Nga Bay findings should not be generalised to other coasts.