thumb|Mount Lidgebird and Mount Gower, twin Mountains to the south of Lord Howe Island thumb|View of the Lord Howe Island lagoon, a part of the Lord Howe Island Marine Park
Lord Howe Island Marine Park is the site of Australia's and the world's most southern coral reef ecosystem. The island is 10 km in length, 2 km wide and consists of a large lagoonal reef system along its leeward side, with 28 small islets along its coast.
History of management
Establishment of the Marine Park
The marine park was declared on 26 February 1999 under the Marine Parks Act 1997, with a zoning plan commencing on 1 December 2004 to protect the important natural and cultural values of the park while providing a range of sustainable uses. The marine park status helps protect marine biodiversity from fishing pressure and population pressure.
A range of scientific, social, cultural and economic information was collated to design the zoning plan. In June 2002, a draft zoning plan document was established outlining a number of options for zoning, incorporating the submissions gained through the public comment period, advice taken from the Lord Howe Island Marine Park Advisory Committee and a review of relevant information. This zoning scheme partitioned the coastal waters of Lord Howe Island to permit different human uses, in order to minimise the threat to marine conservation values.
Lord Howe Island's climate is moderated by oceanic air currents and mild sea temperatures. Lord Howe Island is situated at the southernmost limit of coral reef formation, receiving both tropical and temperate open ocean carbon environments. Slowly, over time Lord Howe Island is moving into reef forming seas due to the northward migration of Australia's tectonic plate, which is moving 5–6 cm north per year.
A white sedimentary rock known as calcarenite is locally important within the marine park as it makes up the central and northern regions of the island to below sea level in several places.
The beach and shallow-water calcarenites indicate a sea level around 2–3 m above the present level during the last interglacial period (130,000-70,000 years ago, Pleistocene). Little evidence of reefs during this time can be seen as they may have occupied locations similar to those of modern reefs or were largely destroyed following emergence once the sea level fell.
The fringing reef on the windward western coastline of Lord Howe Island absorbs wave energy and acts as a breakwater preventing storm surges from eroding the low lying central region of the island. The sheltered lagoon contains a number of different reef habitats, dominated by sand, lagoonal corals, gravel sheets, algal flats and patch reefs.
Ecology
The high conservation significance of Lord Howe Island and its waters is recognised by its inclusion on the UNESCO World Heritage List in 1982. Conservation values relating to the marine park include the unique combination of tropical and temperature reef taxa, both flora and fauna.
Fauna
thumb|Providence Petrel, a Lord Howe Island seabird listed as Vulnerable under the NSW TSC ActThe marine life comprise both subtropical and temperate species due to its location and influence of the southerly flowing East Australian Current (EAC).