Results of a study of optical limiting of 532 nm, 15 nsec laser pulses by carbon-black suspensions in pure water and saline water are presented. The optical limiting strength was found to increase as the salinity of the host liquid increased. Particle size measurements showed that aggregation of carbon particles in the saline suspensions resulted in particles with sizes greater than that for the pure water suspension. As the thermophysical properties of the host liquids were nearly the same, the enhanced optical limiting performance is believed to be a direct consequence of the larger size of the carbon particles.