Papua New Guinea

Papua New Guinea (PNG) occupies the eastern half of the rugged tropical island of New Guinea (which it shares with the Indonesian territory of Irian Jaya) as well as numerous smaller islands and atolls in the Pacific.

The central part of the island rises into a wide ridge of mountains known as the Highlands, a territory that is so densely forested and topographically forbidding that the island’s local peoples remained isolated from each other for millennia.

The coastline is liberally endowed with spectacular coral reefs, giving the country an international reputation for SCUBA diving. The smaller island groups of Papua New Guinea include the Bismarck Archipelago, New Britain, New Ireland and the North Solomons. Some of these islands are volcanic, with dramatic mountain ranges, and all are relatively undeveloped.

It is generally agreed that there are 13 seagrass species present in PNG. Seagrass communities in PNG grow on fringing reefs, in protected bays and on the protected side of barrier reefs and islands. Seagrass meadows are a significant feature at several regions in PNG (eg. Manus Island, Wewack, Port Moresby, Milne Bay province and the Tigak Islands and Kavieng) and scattered areas of seagrasses line much of the coastline of NG mainland (eg. Madang, Morobe and Western provinces).

Extensive mixed seagrass meadows are the dominant community type in the bays, harbours and sheltered capes along the coasts of the NG mainland and the islands of New Britian and New Ireland. These extensive seagrass meadows are dominated by T. hemprichii and/or E. acoroides, with up to another 10 species present to varying degrees.

The total area of seagrass meadows in PNG is unknown, as no broad scale mapping exercise has been conducted. The major changes in PNG seagrass meadows would have occurred post World War Two and are related to coastal development, agricultural land use, or population growth. In general though there is insufficient information and no long-term studies from which to draw direct conclusions on historic trends.

These localised impacts are likely to be from soil erosion related to coastal agriculture (eg palm oil plantations), land clearing (eg logging and mining), bush fires and from the discharge of mine tailings. Other effects include sewage discharge, industrial pollution and overfishing. Most of these impacts can be managed with appropriate environmental guidelines, however climate change and associated increase in storm activity, water temperature and/or sea level rise has the potential to damage seagrasses in the region or to influence their distribution. Sea level rise and increased storm activity could lead to large seagrasses losses.