Annex VI of MARPOL provides for the designation of Emission Control Areas, which are areas where the adoption of special mandatory measures for emissions from ships are required to prevent, reduce and control air pollution from NOx or SOx and particulate matter or all three types of emissions and their attendant adverse impacts on human health and the environment. Such areas are included in the 2008 amendments to Annex VI; previously, the Annex only allowed for the designation of SOx Emission Control Areas. Appendix III to Annex VI provides a list of criteria that must be fulfilled in order to obtain designation. Such criteria include such things as information pertinent to the meteorological conditions of the area, the nature of the ship traffic, and assessment of the types of pollutants from ships operating in the area.

Additional reference information: 

• National System MPA Definitions and Criteria
• Marine Protected Areas of the United States