Analysis of heavy metal contents and bioaccumulation characteristics of Acanthaster planci in coral reef of South China Sea

As a natural enemy of corals, Acanthaster planci has caused significant harms to the coral reef ecosystem. However, the heavy metal contents and bioaccumulation characteristics of Acanthaster planci have not been reported. In this paper, the contents of 12 heavy metals (including metalloid As) were determined by inductively coupled plasma mass spectrometry (ICP-MS) in Acanthaster planci collected from coral reefs in the South China Sea. The distribution characteristics were analyzed by Kruskal-Wallis test and principal component analysis. The results showed that V, Cr, Cu, As, Cd, Fe, Zn, Mo were mainly accumulated in the pyloric caeca, gonad and stomach; Mn, Co, Ni, Pb were mainly concentrated in the skeleton, spines and body wall of Acanthaster planci, due to the structural and functional differences of various tissues and organs. Acanthaster planci can easily accumulate Zn, As and Cd in the environment through bioconcentration and biomagnification, and the accumulation characteristics are related to individual metabolic activity and physiological regulation characteristics. The results can provide a scientific basis for understanding the outbreak process of Acanthaster planci and protecting the coral reef ecosystem.