About the listing
Lady Julia Percy island also known by its Aboriginal name Deen Maar or Dhinmar, is Australia's only submarine volcano formed some seven million years ago. When lava erupts under water a typical type of lava called pillow lava occurs. These are tube like structures where the interaction with water forms a crust on the outside and molten lava continues to flow inside. It is Australia’s only off-shore volcano and the only large basalt island off the coast of western Victoria.
This island is home to the largest colony of fur seals in the Southern Hemisphere and several bird species. These include diving petrel, peregrine falcon, fairy prion and sooty oyster catchers. A number of small but unusual plant species survive in the caves in the cliff walls.
The island lies 12 kilometers south of Yambuk, and 22 kilometers south-west of Port Fairy. Lady Julia Percy Island is about 2 kilometers in length by 1 kilometer wide, comprising a plateau in height from 32–46 meters above sea level, surrounded by cliffs, rock platforms and reefs.
With regard to the flora, Frederic Wood Jones said in 1936 of the island, following his leadership of the 1936 McCoy Society expedition:
"A century ago it was covered with a dense, almost impenetrable, growth of the mixed bushy scrub that characterizes certain parts of the coast of the adjacent mainland. Some sixty years ago this dense scrub was still standing over the major portion of the island; but to-day the whole of the plateau is devoid of any growth more majestic than bracken fern and thistles. The whole plateau is, at present, a windswept area, clothed only by vegetation knee-high at the best, and at the worst, by loose volcanic soil or bare rock. This denudation of forest cover is due to human interference, for pigs were at one time turned down on the island, rabbits were liberated and are still living in their thousands, and sealers, fishermen and guano workers have cut down and burned the stunted and wind-blown trees that formerly covered the island."
It is best viewed from The Crags or Yambuk Lake, both of which are in the Yambuk area.
Tours are available and details can be found at the Visitor Information Centre