Elemental concentrations in Brown Seaweed, Padina sp. along the east coast of Peninsular Malaysia

Abstract

A study to illustrate the distribution of trace metals and rare earth elements (REEs) in Padina sp. as a bioindicator was done at 11 stations along the east coast of Peninsular Malaysia facing the South China Sea. The objectives of the study were to obtain baseline data for elemental concentrations (11 trace metals and 14 REEs), to evaluate the spatial variation and inter-elemental relationships, and to define the REEs pattern in seaweed. REEs were measured, as their known close relationship to the heavy metals may assist in the interpretation of metal sources and in determining whether or not there exists anthropogenic accumulation of the metals. Samples were ground to a fine powder, homogenised and quantified by inductively coupled plasma mass spectrometry (ICP-MS). Hg was detected by MA-2 Mercury Analyzer. Metals concentration showed significant variations in their distribution (p < 0.05) and most elements were in their same range of concentrations with the exception of Hg, Cd, Pb and Zn. The presented rank with high concentration of essential elements for metabolism, the partial exclusion of non-essential elements, and the enrichment of LREE over HREE is comparable to other literature. Mean level for metals and REEs were in low concentrations when compared to the literature. With regard to food safety, the concentrations of Hg, Cd, Pb and Zn on a wet weight basis were well within permissible limits set by the Malaysian Food Act. Chondrite and NASC-normalized REEs patterns of each station were generally similar to one another which suggested that they were of similar origin. The REE patterns in Padina sp. were indicative of their provenance from granite rocks, which is dominant in the Malay Peninsula, and volcanic rocks to a lesser extent. This study demonstrated that because of the close relationship of Fe and the contaminant metal Pb with the REEs, the relatively high concentrations of these metals point to their source being the granitic rocks.

Keywords:

• biomonitor
• South China Sea
• trace metals
• rare earth elements
• granite