Sudbury Reef is a small coral reef

Coral reef

Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...

, with a few unnamed cay

Cay

A cay , also spelled caye or key, is a small, low-elevation, sandy island formed on the surface of coral reefs. Cays occur in tropical environments throughout the Pacific, Atlantic and Indian Oceans , where they provide habitable and agricultural land for hundreds of thousands of people...

s but no substantial islands, lying about 20 km off the east coast of Far North Queensland

Far North Queensland

Far North Queensland, or FNQ, is the northernmost part of the Australian state of Queensland. The region, which contains a large section of the Tropical North Queensland area, stretches from the city of Cairns north to the Torres Strait...

, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. It is part of the Great Barrier Reef Marine Park

Great Barrier Reef Marine Park

The Great Barrier Reef Marine Park protects a large part of Australia's Great Barrier Reef from damaging activities. Fishing and the removal of artefacts or...

 at about the same latitude as Cairns

Cairns, Queensland

Cairns is a regional city in Far North Queensland, Australia, founded 1876. The city was named after William Wellington Cairns, then-current Governor of Queensland. It was formed to serve miners heading for the Hodgkinson River goldfield, but experienced a decline when an easier route was...

.

Birds

The reef has been identified as an Important Bird Area

Important Bird Area

An Important Bird Area is an area recognized as being globally important habitat for the conservation of bird populations. Currently there are about 10,000 IBAs worldwide. The program was developed and sites are identified by BirdLife International...

 (IBA) by BirdLife International

BirdLife International

BirdLife International is a global Partnership of conservation organisations that strives to conserve birds, their habitats and global biodiversity, working with people towards sustainability in the use of natural resources...

 because its cays, with a collective land area of about a hectare, have supported over 1% of the world population of Lesser Crested Tern

Lesser Crested Tern

The Lesser Crested Tern is a seabird of the tern family Sternidae...

s (with up to 5000 nests recorded).