Background levels of heavy metals in nine tropical seagrass species in Indonesia

Abstract

Tropical marine environments are increasingly threatened by heavy metal pollution and yet very little is known about the effects of these trace elements upon coral reefs and adjoining seagrass beds. Natural background levels for Cd, Cu, Pb and Zn were estimated in 9 tropical seagrass species ( Cymodocea rotundata, C. serrulata, Thalassia hemprichii, Syringodium isoetifolium, Enhalus acoroides, Halodule uninervis, H. pinifolia, Thalassodendron ciliatum, Halophila ovalis) from pristine coastal localities in the Flores Sea, Indonesia. Above- and below-ground plant parts were analysed separately and showed extremely low metal values for most seagrass species compared to its literature data. Natural accumulation of heavy metals may occur in certain seagrass species. It is suggested that seagrasses may be used as indicator organisms for heavy metal contamination and bioavailability at the start of the food chain in marine habitats.