Lord Howe Island Marine Park is the site of Australia's and the world's most southern coral reef ecosystem.

Both Lord Howe Island and Balls Pyramid are incorporated within the three nautical miles protected by the state marine park.

Lord Howe Island Marine Park was declared after it was recognised as an area with outstanding natural values, an extraordinary array of marine habitats and biodiversity, rich maritime cultural heritage and social and economic importance to the island community, giving it both national and international importance.

[2] Due to its isolated geographic location, small size and limited access, there are a number of threats to biodiversity that require management.

The EPBC Act provides guidance about regional biodiversity conservation priorities through the implementation of the marine bioregional planning process.

[5] 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.

73.2% of the Marine Park, known as Habitat Protection Zones, allows most forms of fishing: charter boat and recreational, but excludes spearfishing.

[2] The zoning plan gives protection to important natural and cultural values of the marine park, while allowing sustainable use including swimming, surfing, charter and recreational fishing, scuba diving, sailing, boating and research.

[3] Lord Howe Island is regarded as having high geological, geomorphological and geodiversity values, many of which extend to the habitats of the marine park.

[7] Lord Howe Island is situated at the southernmost limit of coral reef formation, receiving both tropical and temperate open ocean carbon environments.

[8] 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.

[12] 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.

[5] Lord Howe Island was only discovered by humans in 1778, consequently the original flora and fauna has remained relatively untouched.

[5] Also, two species of non-endemic sea grasses are found within the marine park: Eelgrass, Zostera muelleri subsp capricorni and Paddleweed, Halophila ovalis.

[13] The marine life comprise both subtropical and temperate species due to its location and influence of the southerly flowing East Australian Current (EAC).

[3] Anthropogenic climate change is listed as a Key Threatening Process under the NSW Threatened Species Conservation (TSC) Act 1995 while loss of climatic habitat caused by anthropogenic emissions of greenhouse gases is listed under the Environmental Protection and Biodiversity Conservation (EPBC) Act.

[10] The lagoon is six kilometres long and 1.5 km wide and contains the largest of Lord Howe Island's coral reef system, assessed as having World Heritage values.