In “MPA Tip”, we present advice on MPA planning and management. Below, a technique for monitoring ship traffic is described. The purpose is to help avoid vessel damage to sensitive areas, such as through groundings or illegal anchoring.

This tip was adapted by MPA News with permission from Duncan Vaughan, who described the technique on the Coral ListServer ( in September 2007. Vaughan is the deputy clerk and fishery officer for the Eastern Sea Fisheries Joint Committee in the UK.

Tip: MPAs should consider using the Automatic Identification System, or AIS, to monitor ship traffic. Since December 2004, AIS has been required by the International Maritime Organization to be installed on virtually all large commercial ships worldwide, including tankers and cruise liners. The technology uses a normal VHF signal and automatically transmits the vessel’s name, position, course, speed, and rate of turn. Other information, even the type of cargo it is carrying, can be input by the crew of the vessel.

To track AIS signals, an MPA needs to install a VHF antenna and base station, both on land. The base station is then connected to a computer that can store the movements of vessels that come into range (the range depends on the height of the antenna, although 20 nautical miles is not uncommon). Should there be an enforcement incident involving a vessel fitted with AIS, the recorded movements of the vessel can be submitted as evidence. It is possible to link the AIS to a pager or cell phone, so that when a ship enters a no-go zone it gives automatic notice and managers can respond accordingly. To make the set-up process easier, you may want to subscribe to an AIS provider, such as AIS Live ( or others. The cost of an installation kit is about US $2500. The use of AIS was recently promoted as a management tool by St. Eustatius Marine Park in the Caribbean to combat illegal anchoring in the MPA.

Although commercial fishing vessels are not required under international law to carry an AIS, licensed fisheries can make it a condition to have the technology on board. This provides nearby MPA managers with a tool for monitoring fishing activity inside their protected areas.

For more information

Duncan Vaughan, Eastern Sea Fisheries Joint Committee, Norfolk, UK. E-mail:

International Maritime Organization AIS website

US Department of Homeland Security AIS website

St. Eustatius Marine Park