Granite Island granite
Granite Island was once connected to the mainland. It has survived the force of the ocean while the land that once surrounded it eroded away. The granite that makes up the Island was formed about 10 km below the surface of the earth.
Extreme pressure in the earth's crust folded layers of sediment. At the same time, extreme heat melted the base rock. The molten rock was forced upwards into weak points in the earth's crust - Granite Island was located at one of these weak points. The molten rock cooled and hardened into granite. This happened about 480 million years ago. Over millions of years, the thick layers of sediment that covered the granite were gradually eroded away by water, exposing the granite beneath. Source
Granite Island is situated off Victor Harbor in South Australia and connects to the mainland by a causeway. The entire island is controlled by National Parks and Wildlife Service, however the flat northern shore is leased for development. The result is a unique joint management arrangement. A Friends of Granite Island group is being developed to allow community involvement on a volunteer basis.
Prior to 1994 the island was designated crown land, which was managed by the District Council. The island received a major facelift in 1994 by the Greater Granite Island Development Company, with stage one of an 11 million dollar development. In January 1995 the cafe, Kiosk, Souvenir shop and Penguin Centre were opened.
The DEHAA (Dept of Environment, Heritage and Aboriginal Affairs) took over from mid 1998.
Granite Island has historical and cultural significance for the Ngarrindjeri people and is included in the Dreaming legend of Ngurunderi. It also has historical and heritage value for European people.
Current facilities include a cafe, kiosk, souvenir shop, penguin centre and public toilets. A horse drawn tram controlled by the District Council of Victor Harbor operates daily.
Granite Island is home to a colony of approximately 150 little penguins (Eudyptula minor) and guided tours operate each evening at dusk.
Problems caused by unguided visitors include the use of white torches and camera flashes which interfere with the penguins vision and cause disorientation. Approaching the penguins closer than 5 metres, touching penguins, eggs and burrows which places stress on the birds. Obstructing the penguins nightly pathway, preventing them from returning to their burrows and in breeding season delaying or prevent chicks from being fed. On occasion penguins have been beaten to death or left wounded by vandals.
Due to the direct and indirect interference placed on the colony by visitors, it is necessary for all people wishing to view the penguins in the first 2 hours after dark, to join a guided tour. Visitors Guided tours are then taken on a tour of the northern shore, with a professional tour guide who provides information and interpretation on the penguins adaptations and behaviour.
Island discovery walks and extensive school programmes can be tailored to suit group needs, ages and studies. Whale tours are available in season, following the history of whaling in Encounter Bay and interpreting the behaviour of southern right whales when they are visible.
A penguin management plan has been formulated to best protect the penguin colony and their habitat. Long term improvements include the construction of a boardwalk and viewing platforms to separate people from penguins. The increase of habitat through nesting box placement and the planting of ‘penguin friendly’ indigenous vegetation.
Research is conducted on Granite Island to monitor the health of the colony. Human impacts and impacts caused through construction and development are monitored by studying breeding success and chick survival rates. Research is also conducted to assess changes and trends in the number of penguins in this population through on-going active burrow counts. Many other research opportunities exist for post graduate university students.