Aerial view of Erith Island
The Park typifies the region’s geological history, being composed of a granite intrusion, overlain by younger sediments. The granite is part of a large bathylith extending from Wilson's Promontory to north-east Tasmania. During an early Quaternary ice-age low sea levels exposed the continental shelf and wind blown sands deposited in the group, typically along the west/windward side of islands. The calcareous dunes have subsequently been subject to consolidation and secondary cementation, forming aeolianite. These limestone and limesand deposits now veneer the group’s granite bedrock.
The group is high compared to many others rising to 305 metres above sea level at its highest point on Deal Island.
The vegetation of the Park is broadly typical of the islands of Eastern Bass Strait. The major community types are dominated by Poa tussock grasses, drooping sheoak Allocasuarina verticillata, Smithton peppermint Eucalyptus nitida, boobialla Myoporum insulare, and teatree including coastal teatree Leptospermum laevigatum.
Dover Island is the least impacted by fire and human activity. It is largely covered with low forest, closed scrub and heath and it is almost totally free of weed species. Erith Island exhibits the most human influence. Until 1996 the island was the subject of a commercial grazing lease and underwent frequent associated firing. The island is largely covered by open Poa grassland and a high number of invasive exotic species.
The national park has biogeographic significance. The native flora of the Bass Strait islands is uniquely transitional between mainland and Tasmania floras, and contains many geographic outliers; species which are either at the northern or southern end of their range. As a result there are many species not normally found in association. The heath community found on the higher parts of Dover Island has considerable conservation significance, being unique and only reserved in this location.
The Kent Group is an important Australian fur seal breeding site and is the largest of only five sites in Tasmanian waters. It is especially significant because, unlike other sites, it is secure from high seas when pups are young and vulnerable. The islands are also important sanctuaries for the common diving petrels and fairy prions, and are home to significant colonies of short-tailed shearwaters, little penguins, sooty oystercatchers, cormorants and terns. Deal Island is a highly modified island, with very little of its natural environment intact due to fire, land clearing and grazing. The diversity of terrestrial birds and reptiles is of significant importance. The larger islands also are habitat for a range of native animals such as bandicoots, potoroos and possums.
The Kent Group was discovered by Mathew Flinders in 1798, during a voyage to Preservation Island to rescue survivors of the wreck of the Sydney Cove.
It was the investigations of Mathew Flinders that led to the discovery of the vast Australian Fur seal colonies around the Kent Group of Islands. The further exploration of Bass Strait soon followed this. Some of the sealer settlements in Eastern Bass Strait were amongst the earliest European Settlements outside Sydney Cove.
The Kent archipelago was named after William Kent, commander of the Supply, by Governor Hunter, although others claim that the nomenclature was chosen by Flinders himself. Some of the sealer settlements in Eastern Bass Strait were amongst the earliest European Settlements outside Sydney Cove.
By the 1820s a number of sealers had made more permanent homes for themselves on the Islands. In 1803 the great British Botanist Robert Brown landed on Deal Island and made extensive collections. This led to the findings that Deal Island was home to many species of marine algae as well as terrestrial species.
In 1848 a lighthouse was built on the largest of the three islands - Deal. Convicts and bullock teams built the lighthouse over a period of several years. The lighthouse was completed with the help of the then New South Wales, Victorian and Tasmanian Governments, with the aim that it would enable more free trade through the waters of Bass Strait. The lighthouse was built on a hill top that rose 288 metres above sea level. Before its light was turned off, in 1992 (and replaced by smaller lights on Northeast Island and Southwest Island), the light was sometimes visible at night time from Wilsons Promontory in Victoria, some 80 kilometres away.
The island was used for cattle grazing for a short period in the early 1930s. During this time there were stock yards and one small hut constructed at West Cove on Deal Island and substantial clearing was undertaken. The impacts of grazing and agricultural use of Deal Island has had a severe impact on the natural environment.
Brothers, N., Pemberton, D., Pryor, H. and Halley, V. (2001) Tasmania's Offshore Islands: seabirds and other natural features.