HEAVY METALS DISTRIBUTION AND FRACTIONATION IN MANGROVE SEDIMENTS LINKED TO ORGANIC DEPOSITS VIS-A-VIS ACCUMULATION IN RHIZOPHORA SPP. AT TANJUNG PIAI, JOHOR, MALAYSIA

Mangrove ecosystems are crucial for ecological processes. However, mangrove forests are currently under peril due to urbanization, aquaculture expansion, and growing pollutant burdens. Marine debris including organic deposits (ODs) is intentionally or unintentionally deposited into the marine environment, which could alter the natural ecology of the ecosystem. ODs from Tanjung Piai, Johor, Malaysia have high concentration of heavy metals (HMs), specially Cd and PB, with respective concentration of 2.45 mg kg(-)and 82.41 mg kg(-1), which surpassed the compost guidelines of the European and United Kingdom. Four sampling sites were established in Tanjung Piai based on ODs levels: T1: without ODs, T2: new ODs, T3 and T4: decomposed ODs 90 m and 150 m from shoreline, respectively. T3 and T4 had the highest Cu and Pb. Modified sequential extraction European Community Bureau of Reference (BCR) reveals that Fe and Mn are highly mobile for mangrove species uptake, with concentrations of these HMs in Rhizophora spp. leaves higher than Cd, Pb, and Zn, implying that these species did not meet the criteria for hyperaccumulators due to low metals accumulation, necessitating further research to identify species suited for phytoextraction of HMs.

Automated summary

Mangrove ecosystems are crucial for ecological processes, but they are currently facing threats from urbanization, aquaculture expansion, and increasing pollutant burdens. Organic deposits in marine debris contain high concentrations of heavy metals, posing a risk to the natural ecology of mangrove forests. Further research is needed to identify species suitable for phytoextraction of heavy metals.