Non-metric multidimensional scaling and human risks of heavy metal concentrations in wild marine organisms from the Maowei Sea, the Beibu Gulf, South China Sea

We investigated heavy metal concentrations in wild marine organisms from Maowei Sea, a significant gulf of low-latitude developing regions of the Beibu Gulf, South China Sea. Twenty species, comprising fish, cephalopods, and crustaceans were collected and analyzed for heavy metals. Heavy metal levels (mg/kg, wet weight) in the aquatic organism samples were: 0.003-1.800 for Cd, 0.02-0.14 for Pb, 0.10-0.63 for Cr, 0.20-77.50 for Cu, 9.50-64.60 for Zn, 0.006-0.066 for Hg, and 0.10-1.50 for As. Non-metric multidimensional scaling coupled with cluster analysis revealed two groupings that mainly resulted from different species of the metals in marine organisms. The highest concentrations of Cd, Pb, Cr, Ni, Cu, Zn, Hg, and As were found in species of cephalopods. Health risk assessment based on the target hazard quotients (THQ) and total THQ indicated no significant adverse health effects from consumption of marine organisms.