Vessel Traffic Overview

Updated:October 9, 2009 15:04

Vessel Traffic Calling in the Aleutains Subarea

 

Figure 7 shows the primary traffic routes of vessels calling at ports in the Aleutians Subarea. Unalaska/Dutch Harbor is by far the largest port in the area; most port calls occur there. Other locations where port activities occur include - Adak, Gusty Bay/Tanaga Island, Saint George, Akutan, King Cove, Saint Paul, Atka, Kiska, Sand Point, Beaver Inlet, Unalaska Island, Makushin Bay, Unalaska Island, and Tanaga.

The U.S. Coast Guard maintains records of vessels calling at Unalaska/Dutch Harbor. Table 3 contains port calls to Unalaska/Dutch Harbor by vessel type and month in 2004. The vast majority (94%) of port calls (not counting fishing trawlers, catchers and processors) were made by three vessel types: container ships (38%), reefers (29%), and tug/barges (27%). Figure 8 shows the distribution of the Unalaska/Dutch Harbor port calls by month and vessel type. During both 2004 and 2005, calls peaked in July with 47 vessels calling at the port. The month with the least number of port calls was December, when only 17 vessels called at the port (Table 3).

Data on vessel calls to the other Aleutian ports was not readily available, but some general information is known. No other port in the Aleutians receives container ships, so most of the calls to these ports are fishing trampers (reefer) and tug/barges. Fishing trampers and tug/barges that call at the other Aleutian ports usually call at Unalaska/Dutch Harbor too, so the 376 voyages shown in Table 3 represent almost all of the vessel traffic calling in the Aleutians Subarea.

The highest risks for environmental damage from oil spills are from vessels carrying persistent fuel. Most vessels over 400 gross tons that call in Alaska are required to have a State contingency plan and a COFR. Table 1 and Figure 3 summarize information about vessels registered to trade in Alaska. Using this information, the estimate of fuel capacity for large vessels calling at Aleutian ports in 2004, 2005 and the first half of 2006 is:

• 130 container ships per year with a typical fuel capacity of 1.6 million gallons of persistent fuel oil each, and
• 108 reefer (refrigerated) cargo ships with a typical fuel oil capacity of 317,000 gallons of mostly persistent fuel oil.

The only other ships that may use persistent fuel are the cruise ships and tank ships. These ships make few calls in the Aleutians Subarea but carry relatively large volumes of persistent oil.