Vessel Traffic Overview

Updated:October 9, 2009 15:05

Analysis of Vessel Traffic in the Aleutians Subarea

For the purpose of this analysis, information on vessel traffic in the Aleutians Subarea was considered to identify the annual numbers of vessels carrying persistent and non-persistent oils as fuel or bunkers and to estimate the quantities of oil onboard.

No single data set contains all information needed to develop a precise picture of the number, type, size, and fuel capacity for vessels transiting the Aleutians. Vessels transiting the area in innocent passage are not required to report to the U.S. Coast Guard or the State of Alaska. Information gathered from the sources used in this report is presented in various forms that are not always comparable. For example, the U.S. Coast Guard and State of Alaska use dissimilar vessel classification schemes. In developing this analysis, we compared, combined, and extrapolated information from similar, but not exact, datasets to provide the best possible estimates. These methods included:

• Using the Alaska Department of Environmental Conservation (ADEC) nontank vessel contingency plan database to characterize types of vessels for size and fuel capacity;
• Using 9 months of vessel tracking data from the ship automated identification system (AIS) receiver recently established at Scotch Cap, Unimak Pass;
• Calculating tanker cargo capacity for AIS reports and records available on Lloyd’s Register;
• Correlating the National Marine Fisheries Service groundfish fishery observer’s database with the Alaska Commercial Fisheries Entry Commission’s vessel database to estimate the size and fuel capacity of this fleet.