The marine fish samples were randomly collected and purchased
from fishing boats and local fish markets in nine coastal cities
of East China including Dalian, Tianjin, Qingdao, Shanghai,
Zhoushan, Wenzhou, Fuzhou, Quanzhou, and Xiamen in 2008
(Fig. 1). Two species of fishes, large yellow croaker (Pseudosciaena
crocea) and sliver pomfret (Pampus argenteus), were caught in local
waters as confirmed by local fishermen. Procedures for sample
preparation have been described previously (Xia et al., 2011).