The number concentrations of bacteria, viruses, and insoluble submicrometer particles in seawater were simultaneously measured to investigate the effects of biological activity and anthropogenic sources on the number of submicrometer particles in seawater sampled at various coastal locations during different seasons and at varying tidal levels. It was found that when an anthropogenic source was located near a sampling site, there was an increase in the number concentration of insoluble submicrometer particles, as well as enhancements of anthropogenic elements. The concentration of insoluble submicrometer particles was the highest at the Taean site, which had the strongest biological activity. The particle concentration was two to three times higher in spring than in summer or winter, which aligns with the observation that spring had the highest biological activity, which may be caused by the increase in solar radiation and nutrients. During spring tide, when there is maximum tidal variation, strong mixing and the suspension of accumulated sediments can occur. At this time, there were significant increases in the number concentrations of insoluble particles and viruses in seawater. Data suggest that the location, season, and tidal level have great impacts on the biological materials in seawater, which affects the number of insoluble submicrometer particles, and contributes to primary marine aerosols produced by the bubble bursting process. (C) 2014 Elsevier Ltd. All rights reserved.