Particulate matter at the estuarine salt marsh surface microlayer: Particle-size distributions and comparison to bulk suspension

Particle-size distributions have been measured for paired samples from the surface microlayer and bulk suspension in a South San Francisco Bay salt marsh. Comparison of size distributions reveals no consistent differences in surface microlayer and bulk particle populations; however, particle numbers were, at times, considerably enriched at the marsh microlayer. An empirical power curve was found to fit the particle-size distributions. The fitted exponents of particle size distributions indicate a slightly greater fraction of particle volume and a substantially greater fraction of particle surface area reside in small (colloidal) particle-size ranges.