1) In order to perform an acute toxicity assessment of a new algicide, thiazolidinedione derivative (TD53) with enhanced solubility and lower toxicity to marine ecosystem, representative 3 organisms: plant plankton (Skeletonema costatum), animal plankton (Daphnia magna), fish (Paralichthys olivaceus) related in the food chain of marine ecosystem according to OECD standard methods were employed in the exposure experiment.

1) In this study, a newly synthesized thiazolidinedione derivative, TD49 with a highly selective algicide to red tide, was examined in order to evaluate the bioconcentration on aquatic organisms of coast. BAF (accumulation of TD49 by aquatic food chain) and BCF (accumulation of TD49 by sea water) were examined employing the shrimp (Fenneropenaeus chinensis) as the feed organism, and the olive flounder Paralichthys olivaceus as a consumer in marine ecosystem. Bioconcentration degree in sea water showed that the order in P. olivaceus was viscera > gill > muscle. The average BCF values of TD49 were 67.70, 63.32 and 20.25 at viscera, gill and muscle, respectively. Bioaccumulation degree using feed showed that the order in the organs of P. olivaceus was viscera > gill > muscle. respectively. When compared with two results, the accumulation by the food and water was higher than that by water. After the elimination experiment in sea water, the TD49 concentration was 2.81 nmole/g in the viscera and were not found in the gill and the muscle. More than 50% of the accumulated TD49 were eliminated from viscera in 7 days and all the accumulated TD49 were eliminated from gill and muscle in 7 days. On the other hand, the octanol/water partition coefficient (log Kow) was measured to be 3.66 and experimental BCF of this study was 67.7.