Spatiotemporal Distribution and Bioaccumulation of Arsenic Species in the Aquacultural Ecosystem in the Coastal Areas of Southwestern Taiwan

Abstract
This study analyzed the spatiotemporal distribution and bioaccumulation of arsenic (As) species in the aquacultural ecosystem for different aquacultural conditions in the coast of southwestern, Taiwan. The analyzed aquacultural fishes and shellfishes included tilapia, oyster (Crassostred gigas), mugil (Mugil cephalus) and clam (Meretrix lusoria). The bioaccumulation paths were investigated according to the As species contents in different tissues of four aquacultural fishes and shellfishes. The study area focused on the blackfoot disease and coastal areas where groundwater contains high As. The analyzed components of the aquacultural ecosystem contained the As species concentrations in groundwater, aquacultural ponds and sea, in biological tissues (including soft organ, muscle, ovary etc.) of the fishes and shellfishes, and in pond sediments. The analyzed As species included total As, arsenate As(Ⅴ)and arsenite As（Ⅲ）, monomethylarsonic acid（MMA）, and dimethylarsinic acid（DMA）.
The As concentrations of the aquacultural ponds positively correlate with those used groundwater (R=0.51, p<0.01) in the study areas, while the correlation in the aquacultural ponds of tilapia (R=0.73, p<0.01) is the highest among the others. The dating of groundwater of high As concentrations in the blackfoot disease(BFD) area is close to that in Kouhu township of Yunlin but the formation depths of these two area are different. For one year survey of oyster, the average total As and inorganic As concentrations are 9.85