Over the last several years, concern has increased aboutthe amount of man-made materials lost or discarded atsea and the potential impacts to the environment. Thescope of the problem depends on the amounts and typesof debris. One problem in making a regional comparisonof debris is the lack of a standard methodology. Theobjective of this manual is to discuss designs and methodologies for assessment studies of marine debris.This manual has been written for managers, researchers,and others who are just entering this area of studyand who seek guidance in designing marine debris surveys.Active researchers will be able to use this manualalong with applicable references herein as a source fordesign improvement. To this end, the authors have synthesized their work and reviewed survey techniques thathave been used in the past for assessing marine debris,such as sighting surveys, beach surveys, and trawl surveys,and have considered new methods (e.g., aerial photography).All techniques have been put into a general surveyplanning framework to assist in developing different marinedebris surveys. (PDF file contains 100 pages.)