This report presents a new methodology for averaging and summarizing large volumes of data resulting from polychaete annelid worm sampling studies into a simple, comprehensible form useful in nearshore environmental monitoring and assessment. The result is a Polychaete Assemblage Characterization (PAC) for each location or habitat sampled, involving community parameters of taxon richness, density, and diversity and a list of major taxa encountered. Changes observed in the PAC of a habitat over time should be indicative of the nature and degree of environmental changes occurring there. (Author).