Abstract:
Accumulation of heavy methals in above and below ground structures of four seagrass species; Enhalus acoroides (Linnaeus f.) Royle, Cymodocea serrulata (R. Brown) Ascheron and Magnus, Halophila ovalis (R. Brown) Hooker f. and Halodule pinifolia (Miki) den Hartog was studied. Seagrasses and sediment samples were collected from Sattahip district, Chonburi province during wet (October,2002) and dry (April ,2003) seasons. The samples were digested with concentrated acid prior to metal determination. Mercury concentration was determined by using Cold-Vapor Atomic Fluorescence Spectrophotometer (CVAFS) while cadmiun, lead, copper, zinc, iron and manganese were determined by Atomic Absorption Spectrophotometer (AAS). All studied metals (expect iron) were found to accumulate significantly higher in above groung than below gouund structures of the seagrasses. Mercury, cadmium, lead and zinc cocentration in the west season were significantly higher than those in the dry season while copper, manganese and iron concentrations in the dry season were significantly higher than those in the wet season. In both seasons, murcury, lead and copper concentrations were highest in Enhalus acoroides. Cadmium and manganese concentration were highest in Cymodocea serrulata while iron concentration in Halophila ovalis were similar to those in Cymodocea serrulatabut higher than those in Enhalus acoroides.Zinc concentrations was not significantly different in the four seagrasses species. Moreover, lead copper and zinc concentrations in Halodule pinifolia collected from the sea in the front of Apakron hospital were higher than those from the Naval base while mecury, cadmium, manganese and iron concentrations in Halodule pinifolia from Naval base were higher than those in the samples collected from the hospital. Heavy metals concentrations in above and below structures of seagrasse from Smaesan Island and Hospital show no correlation with heavy metals concentration in sediment.