The purpose of the series is to provide guidance for monitoring of priority pollutant residues in tissues of resident marine organisms. These guidance documents were prepared for the 301(h) sewage discharge permit program under the U.S. EPA Office of Marine and Estuarine Protection, Marine Operations Division. Two kinds of monitoring guidance are provided in this series: recommendations for sampling and analysis designs, and aids for interpretation of monitoring data. Although these guidance documents were prepared specifically for monitoring of sewage discharges under the 301(h) program, their potential use extends to assessment and monitoring of bioaccumulation resulting from other kinds of pollutant discharges into marine and estuarine environments.