A Mexican company plans to sell artificially cultured and cleansed adult scallops, Argopecten circularis, to Mexicans and Europeans for human consumption. A series of six experiments, comparing the effectiveness of ozone vs chlorine depuration in adult A. circularis, was performed at the aquaculture facility in La Paz. It was quite difficult to maintain oxidant residuals due to the extreme ambient temperature (+42˚C), but experiments did show that both oxidants, chlorine and ozone, reduced total plate count 90–94‰ and chlorine treatment depurated scallops of coliform in the experimental treatment time.