Carbon nanoparticles are one of the most promising groups of nanoparticles. Their versatile properties give them potential in various applications including widely produced and sold consumer products. It is unrealistic to assume that fullerenes could be produced and used without any releases. Releases may induce risks in the environment because nanoparticles can behave in a different way than expected for “traditional” chemicals. Nano-size offers special reactivity and ability to penetrate physiological barriers that are lacking in bigger forms of the same matter. Thus, nano risk assessment needs special attention. The present work reveals fullerenes’ fate in aquatic environments, and demonstrates their effects on two aquatic species.