Deal Island is a granite

Granite

Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...

 island, with an area of 1576.75 ha

Hectare

The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...

, in south-eastern 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 the largest of Tasmania

Tasmania

Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...

’s Kent Group

Kent Group

The Kent Group of Islands lies in Bass Strait, Australia, north-west of the Furneaux Group. They form the Kent Group National Park.The islands were named Kent's Group by Matthew Flinders, "in honour of my friend captain William Kent, then commander of the Supply" when Flinders passed them on...

, lying in northern Bass Strait

Bass Strait

Bass Strait is a sea strait separating Tasmania from the south of the Australian mainland, specifically the state of Victoria.-Extent:The International Hydrographic Organization defines the limits of the Bass Strait as follows:...

 between the Furneaux Group and Wilsons Promontory

Wilsons Promontory

Wilsons Promontory is a peninsula that forms the southernmost part of the Australian mainland and is located at . South Point at is the southernmost tip of Wilsons Promontory and hence of mainland Australia...

 in Victoria. It is now part of the Kent Group National Park, Tasmania’s northernmost national park

National park

A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individual nations designate their own national parks differently A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or...

, which was gazetted in 2002. In 2004 the national park was extended to include the state waters of the three major islands of the Kent Group marine waters.

The Beagle Commonwealth Marine Reserve, the Kent Group, is located at the southern end of the Commonwealth reserve.

Deal Island has been extensively modified in the past by human activity in the construction of facilities and the vegetation clearance and regular firing associated with grazing livestock. It has a lighthouse

Lighthouse

A lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses or, in older times, from a fire, and used as an aid to navigation for maritime pilots at sea or on inland waterways....

, airstrip (closed), roads, jetty, four houses, a dam and a museum.

Lighthouse

Deal Island has the highest lighthouse

Lighthouse

A lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses or, in older times, from a fire, and used as an aid to navigation for maritime pilots at sea or on inland waterways....

 in the Southern Hemisphere

Southern Hemisphere

The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...

, standing 305 m above sea level

Above mean sea level

The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach...

. The height has caused problems with visibility in low cloud conditions. The lighthouse was built in 1848 and deactivated in 1992. Management and conservation is under the control of the Tasmania Parks and Wildlife Service

Tasmania Parks and Wildlife Service

Tasmania Parks and Wildlife Service is the Tasmanian Government body responsible for the care and administration of Tasmania's National Parks and wildlife.-History:...

.

Fauna

Recorded breeding seabird

Seabird

Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...

 and wader

Wader

Waders, called shorebirds in North America , are members of the order Charadriiformes, excluding the more marine web-footed seabird groups. The latter are the skuas , gulls , terns , skimmers , and auks...

 species include Little Penguin

Little Penguin

The Little Penguin is the smallest species of penguin. The penguin, which usually grows to an average of in height and in length , is found on the coastlines of southern Australia and New Zealand, with possible records from Chile.Apart from Little Penguins, they have several common names...

, Pacific Gull

Pacific Gull

The Pacific Gull is a very large gull, native to the coasts of Australia. It is moderately common between Carnarvon in the west, and Sydney in the east, although it has become scarce in some parts of the south-east, as a result of competition from the Kelp Gull, which has "self-introduced" since...

, and Sooty Oystercatcher

Sooty Oystercatcher

The Sooty Oystercatcher, Haematopus fuliginosus, is a species of oystercatcher. It is a wading bird native to Australia and commonly found on its coastline. It prefers rocky coastlines, but will occasionally live in estuaries....

. Mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s found on the island are the Red-necked Wallaby

Red-necked Wallaby

The Red-necked Wallaby is a medium-sized marsupial macropod, common in the more temperate and fertile parts of eastern Australia, including Tasmania.- Description :...

, Common Brushtail Possum

Common Brushtail Possum

The Common Brushtail Possum is a nocturnal, semi-arboreal marsupial of the family Phalangeridae, it is native to Australia, and the largest of the possums.Like most possums, the Common Brushtail is nocturnal...

, Southern Brown Bandicoot

Southern Brown Bandicoot

The Southern Brown Bandicoot , also known as the Quenda from the local Noongar tongue from South Western Australia, is a short-nosed bandicoot found mostly in southern Australia....

, as well as the introduced European Rabbit

European Rabbit

The European Rabbit or Common Rabbit is a species of rabbit native to south west Europe and north west Africa . It has been widely introduced elsewhere often with devastating effects on local biodiversity...

. Reptile

Reptile

Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...

s present include the Metallic Skink

Metallic Skink

The Metallic Cool-skink or Metallic Skink is a species of skink in the Scincidae family. It is endemic to Australia, found in southern Victoria, as well as in Tasmania where it is the most widespread and common lizard, occurring on many offshore islands in Bass Strait as well as the mainland. It...

, Bougainville's Skink

Bougainville's Skink

Bougainville's Skink is a species of skink in the Scincidae family. It is found in south-eastern Australia, including north-eastern Tasmania and many Bass Strait islands. It has very reduced limbs and moves in a snake-like manner. It is seldom seen as much of its life is spent beneath...

, White's Skink

White's Skink

White's Skink is a species of skink in the Scincidae family. It is found in south-eastern Australia, including Tasmania and many Bass Strait islands. It is slow-growing, to a maximum length of about 90 mm, and may take four years to reach maturity. It gives birth to live young. It is...

 and the White-lipped Snake

White-lipped Snake

The White-lipped Snake is a small species of elapid snake that is restricted to south-eastern mainland Australia and Tasmania. It is the smallest of 3 species of snake found in Tasmania and is Australia's most cold tolerant snake, even inhabiting areas on Mount Kosciuszko above the snow line...

.