Whether viewed from the air or from the sea, Phillip Island is an impressive sight. Lying just six kilometres to the south of Norfolk, the reddish island rises steeply out of the sea to a height of 280 metres. Phillip Island was named after Governor Arthur Phillip, who established the British convict settlement in Sydney in January 1788.
Since 1996, Phillip Island has been part of Norfolk Island National Park and is managed by the Commonwealth of Australia. The island’s barren appearance is a sharp contrast to the green farmland and forested hills of nearby Norfolk Island. Years of investigation by Norfolk locals Owen and Beryl Evans, Honey McCoy and many others, have resulted in a good understanding of the plants and animals that inhabit this island. The seabirds in particular have been well studied.
So, why is Phillip Island so red and so bare of vegetation? Phillip has had a very different history to its larger neighbour. It was first used as a source of Norfolk Island pine, Araucaria heterophylla, and the temporary internment of particularly unruly convicts from Norfolk Island. Phillip Island has also been subjected to intensive grazing by introduced mammals. From very early on, visitors to the island commented on the gradual loss of vegetation, the bare soils and the introduced animals that roamed there in their thousands. Goats, pigs and rabbits almost completely denuded the island of plant cover as their populations increased to unsustainable levels. Only eight years after establishing the settlement on Norfolk Island, Lieutenant-Governor King wrote in 1796 that,
…a great resource for animal food has been found in Philip [sic] Island, which has abounded with the best of food for swine, many having been raised and brought from thence. The great drought during the first part of this year, and the quantity of swine on the island, has destroyed a great part of the weeds and grass on which they feed.
Released onto the island soon after settlement in 1788, for food and perhaps for sport for the soldiers at nearby Kingston, these animals ate their way across the island for more than 200 years before the last rabbit was killed by local people in the late 1980s.
With the forest, scrub and low-growing vegetation removed or greatly reduced, the soils washed into the sea. After heavy storms, the sea around Phillip Island would turn a reddish colour as runoff carried away more than two metres of soil from across the island. The reddish colour? The soils on the island are largely derived from a volcanic rock known as tuff, a rock composed of fragments of volcanic debris thrown out of volcanic vents around 3 million years ago when the island was formed. The rock is soft and very erodible if not covered by vegetation, and is coloured red, as well as pink and orange and purple. Although it is a dramatic landscape and a delight for photographers, it is in fact a sign of a much degraded environment.
Since the elimination of the last rabbit on Phillip Island about 20 years ago, there has been a dramatic increase in the island’s vegetation cover. Large areas of bare soil have been colonised by plants, many have grown from the few plants that survived here and there on the island, while others have arrived from Norfolk Island by wind, voided by birds or attached to their feathers. The spread of the vegetation across the island has been mainly by natural processes, aided by some plantings and weed control by local volunteers and National Park staff and contractors. Although often native to the island, many of the colonising plants are weeds. Some of these weeds must be controlled because they represent a threat to native plants and animals. Although it is a huge task, National Park staff and contractors are removing and killing weeds as resources permit.
The long-term goal is to see native vegetation covering the island once more and weed populations reduced to manageable levels. This will greatly benefit the island’s large seabird populations, where 14 species are known to breed. The island is also home to two unique and threatened reptiles, a skink and a gecko, and an endemic giant centipede growing to over 15 cm long. Because of the absence of rats and cats on Phillip Island, these native animals survived on the island while becoming extinct on Norfolk Island. As the vegetation cover has increased so has the populations of these rare animals greatly increased.
In addition to weed control, the activities undertaken on Phillip Island include propagating native plants from seed in a small green house, propagating the very rare and endemic shrub, the Phillip Island hibiscus (by local Honey McCoy), and monitoring seabird populations.
Vegetation cover and plant diversity have greatly increased in recent years and several plant communities are now developing and beginning to resemble the original vegetation. National Park staff and volunteers are propagating and growing some of the rare plants for planting on the island and woody weeds, such as wild olive, are being progressively removed.
It may take another 100 years before Phillip Island’s vegetation returns to something like it was before Europeans arrived, but it is clear that the process is well underway. Continuing work by the local community and National Park staff will assist the vegetation in returning and developing into stable plant communities.
Visits to Phillip Island should only be made with a local guide. This can be arranged through an accommodation host or by one of the tour companies in Burnt Pine.
Image Credit: Robin Nisbet
Article content disclaimer: Article first published in 2899 Magazine V1 Iss3, 2009. Please note that details of specific travel, accommodation and touring options may be outdated. References to people, places and businesses, including operating days and times may be have changed. References to Government structure and Government businesses/entities may no longer be applicable. Please check directly with businesses and/or Government websites directly rather than relying on any information contained in this article before you make travel arrangements.