The apostles were formed by erosion: The harsh and extreme weather conditions from the Southern Ocean gradually eroded the soft limestone to form caves in the cliffs, which then became arches, which in turn collapsed; leaving rock stacks up to 50 metres high. Because of this erosion, there are eight remaining. The site was known as the Sow and Pigs (Muttonbird Island, near Loch Ard Gorge, was the 'Sow', and the smaller rock stacks were the "Piglets"), the Pinnacles or the Twelve Apostles. The formation eventually became known as the Twelve Apostles, despite only ever having nine stacks. In 2002, the Port Campbell Professional Fishermens Association unsuccessfully attempted to block the creation of a proposed marine national park at the Twelve Apostles location, but were satisfied with the later Victorian Government decision not to allow seismic exploration at the same site by Benaris Energy; believing it would harm marine life.