Great Barrier Reef, Torres Strait and Coral Sea

A particularly sensitive sea area (PSSA) is given special protection because of its vulnerability to damage from international shipping activities.

A PSSA is designated because of its significance for recognised ecological, socio-economic, cultural heritage or scientific attributes that may be at risk of damage from international shipping activities. A PSSA is supported by associated protective measures (APMs). APMs are designed to prevent, reduce, or eliminate risks.

Designation of the Great Barrier Reef, Torres Strait, and Coral Sea PSSA

The Great Barrier Reef was placed on the World Heritage List in 1981. The International Maritime Organization (IMO) designated the Great Barrier Reef as the world’s first PSSA in November 1990. This designation recognised the risks posed by ships transiting the waters of the Great Barrier Reef. It provided additional protection for the outstanding natural qualities of the area.

In 2005, following submissions to the IMO by the Australia and Papua New Guinea governments, the Great Barrier Reef PSSA was extended. The extension to include the Torres Strait region recognised the unique and complex marine ecosystem and its vulnerability to damage by international shipping activities.

In May 2015 the IMO agreed to a further extension. The extension included an area of the south-west Coral Sea to recognise the unique and vulnerable characteristics of the Coral Sea. It also aligns with the key conservation values of the Coral Sea Commonwealth Marine Reserve.

The Great Barrier Reef, Torres Strait and Coral Sea PSSA encompasses an area of approximately 968,000 square kilometres.

Associated protective measures

APMs for PSSAs are limited to actions that are to be, or have been, approved or adopted by the IMO. They are aimed at preventing, reducing or eliminating threats to the area. APMs may include ship routeing and reporting systems, pilotage regimes or vessel traffic services.

APMs in the Great Barrier Reef

The IMO approved a compulsory pilotage regime in the northern part of the Great Barrier Reef inner shipping route and in Hydrographers Passage as an APM. In 1997 an IMO approved mandatory ship reporting system was introduced in the region.

These measures minimise the probability of navigational errors. Navigational errors may result in a maritime accident causing pollution and major damage to the marine environment. The measures also help facilitate a coordinated rapid response in the event of a safety or pollution incident.

APMs in Torres Strait

Two APMs were approved by the IMO for Torres Strait:

  • a two way route in the Great North East Channel
  • an extension of Australia’s system of pilotage to the Torres Strait and the Great North East Channel.

These measures were selected to improve the safety of navigation in an area where freedom of movement of shipping is considerably inhibited by restricted sea-room, and where there are obstructions to navigation, limited water depths and potentially unfavourable meteorological conditions. 

APMs in the south west Coral Sea

Three APMs were approved by the IMO for the south-west Coral Sea:

  • a new recommendatory area to be avoided (ATBA)
  • 2 two-way routes.

The ATBA aims to keep transiting ships away from the many navigational hazards within the area. The two-way routes guide ship traffic around the ATBA. These measures reduce the risk of collisions and groundings. They also allow more time for intervention in developing situations such as a ship suffering a mechanical breakdown.

Other protective measures

A range of other non-IMO adopted protective measures have been implemented. They enhance ship safety and the protection of the marine environment in the Great Barrier Reef, Torres Strait and Coral Sea PSSA. The measures include:

  • designated shipping areas and recommendatory ship routeing systems
  • a comprehensive network of visual and electronic aids to navigation
  • the Great Barrier Reef and Torres Strait vessel traffic service (REEFVTS)
  • no anchoring areas
  • emergency response assets.

Review and evaluation of APMs

The IMO provides a forum for the review and re-evaluation of any adopted APMs. This includes considering comments, reports and observations of the applicable measures that may lead to necessary adjustments to the APMs. IMO member governments with PSSAs can also bring forward concerns and proposals for additional APMs or modifications to any existing APMs or to the PSSA itself. 

Particularly sensitive sea areas

The IMO has a number of PSSA documents about these areas, some information about how PSSAs protect our oceans and an interactive website.

The Coral Sea is considered one of the most distinctive and undisturbed natural systems in the world. It includes the Great Barrier Reef Marine Park and Torres Strait. The Coral Sea Commonwealth Marine Reserve has been created to protect and conserve the biodiversity found in it, while also allowing for the sustainable use of natural resources in some areas. 

Last updated: 19 October 2023