Thistle Island facts for kids

Thistle Island is an island in the Spencer Gulf in South Australia. It is about 200 kilometers (124 miles) west of Adelaide. The city of Port Lincoln is to the northwest. Thistle Island and the nearby Gambier Islands form a chain across the mouth of the Spencer Gulf. This chain connects the southern tips of the Yorke Peninsula and Eyre Peninsula.

The island is about 17 kilometers (10.5 miles) long. It is narrow in the middle, about 1 kilometer (0.6 miles) wide. In the southeast, it gets wider, up to 4 kilometers (2.5 miles) across. On the east coast, there is a large area called Whaler's Bay. A tiny island called Albatross Island is located to the south of Thistle Island.

Since 2014, the Royal Australian Navy has used the waters west of Thistle Island for an acoustic range. This range helps them test and improve sonar technology for submarines. There is also a small control building on the island itself.

Island History

The island was named in 1802 by British explorer Matthew Flinders. He named it after a sad accident. A small boat, led by John Thistle, overturned in rough seas. Seven other men were also on board. They were returning to their ship from the mainland. Even though the ship's crew searched hard, the bodies of the men were never found. Flinders also named other small islands nearby after the lost crew members.

Early whalers found signs of a settlement that didn't last. They saw "the ruins of some cottages" that looked organized. There was even a cleared path between them. People thought these ruins might have been built by survivors of the La Perouse expedition from 1788.

By 1832, a small group of sealers lived on the island. They lived with their Aboriginal wives and children. People believe their camp was on the shore of Waterhouse Bay.

In 1838, the South Australian Company set up a whaling station at Whalers Bay. This was during the time when the British were settling South Australia. A team of experienced whalers came from Tasmania to work there. The station did not catch many whales in 1838 and none in 1839. It was decided that the location was too far from where southern right whales traveled. So, the whaling station was closed.

Today, the historic Whalers Bay Whaling Site and the Thistle Island Sealing Site are protected. They are listed on the South Australian Heritage Register.

Island Geology

Thistle Island is made up of very old, hard rock underneath. On top of this, there are layers of wind-blown sand that have turned into rock. The shores of the island have steep cliffs made of this sandy rock. On the eastern side, there are newer beach sands. You can also find several small lakes behind a strip of sand dunes along the coast.

Albatross Island, which is very small, is mostly made of the same old, hard rock. It also has a thin layer of the wind-blown sandy rock on top.

Animals and Plants

Visitors to Thistle Island in 1877 did not see any little penguins or Australian sea lions. However, they did find many paper nautilus shells on the island's inner beach. In 1904, visitors to Whaler's Bay heard the calls of "hundreds" of little penguins from their boats. In 1932, a visitor named J. T. Mortlock described hearing the "mournful symphony of the curlews and penguins" from the nearby cliffs.

In 1928, a visit to the island was described. On Black Rock, at the north end of Thistle Island, a large group of seals was seen. They quickly swam into the water as a yacht passed by. Many shags (a type of bird) were also there. Other sea birds like gannets, arctic skuas, mollyhawks, and stormy petrels were also observed.

A former mayor of Adelaide, Arden Seymour Hawker, held a fishing record. He caught a 47-pound (21 kg) tuna near Thistle Island in the late 1930s.

In 1996, a survey of South Australia's islands found little penguin breeding sites. It is possible this colony was on Albatross Island, just off the southern tip of Thistle Island.

Thistle Island is now home to a group of greater bilbys. These bilbies were first raised at Monarto Safari Park. By October 2020, the bilby population on Thistle Island was doing very well. So well, in fact, that nine bilbies were moved from Thistle Island to the Arid Recovery Reserve near Roxby Downs. This move helped to make the bilby population there stronger and more diverse.