We evaluated the effects of suspended solids on the survival and physiology of the Kumamoto oyster, . The oysters were exposed to 0, 50, 100, 500, 1 000, or 5 000 suspended solids (SS) for 15 d then returned to clean seawater, without SS, for 15 d. We monitored survival and measured -ATPase, SOD, CAT, and DNA damage in the gills and the RNA/DNA ratio in the muscle tissue+-ATPase, were significantly lower in the groups exposed to SS after 15 d. Furthermore, there were obvious signs of DNA damage in these groups. We observed some recovery in these indices following transfer to clean seawater. However, recovery was incomplete and levels did not return to those of the controls. Our results suggest that these physiological and biochemical indices may be more sensitive than survival as indicators of exposure to increased SS in .