Island on the Edge: An Environmental Catastrophe Is Unfolding on Christmas Island, the Site of Australia's Latest Suspected Mammal Extinction. the Unique Wildlife of the Island Is Struggling to Cope with the Impact of Humans and Introduced Pests
Gilligan, Justin, Ecos
To most Australians, the name Christmas Island is synonymous with its offshore immigration detention centre, and the desperate attempts by asylum seekers to reach Australian soil in crowded, unseaworthy vessels.
But there is another, less well-known story from this jungle-clad outpost of Australia that is just as controversial. Over the past few years, Christmas Island has witnessed an exponential loss of endemic species--those found nowhere else in the world--despite the fact that 63 per cent of its 135 square kilometres is protected as national park. The unique biogeography and remoteness of the island--an isolated volcanic peak in the northern Indian Ocean that is closer to Indonesia than Australia--has intensified the environmental impacts of more than a century of phosphate mining, the introduction of invasive species and an overcrowded detention centre.
'No simple solutions'
Evidence of Christmas Island's rich biodiversity can still be seen, from the lush crown of rainforest to the surrounding deep blue waters of the Indian Ocean. Within the forest, endangered seabirds such as Abbott's booby (Papasula abbotti) feed their young, land crabs scuttle through the leaf litter, and freshwater springs snake through the porous limestone subsoil. Seawards, the thin ribbon of coral reef encircling the island is home to endemic marine fish hybrids, and majestic whale sharks (Rhincodon typus).
Since humans first built permanent settlements about 120 years ago, the island's flora and fauna have faced a growing number of threats, culminating in a wave of extinctions and species declines from the 1980s onwards. The Christmas Island National Park was declared in 1980, with the central aim of protecting and maintaining the island's biological diversity.
Australia's Director of National Parks coordinated an audit of the island's biodiversity between 2003 and 2007. The ensuing Christmas Island Biodiversity Monitoring Program report (1) noted the island's biodiversity as internationally significant, with 253 endemic species, 167 of which have national conservation significance, and 110 that are listed as 'protected' under the Environmental Protection and Biodiversity Conservation Act 1999 (EPBC Act). The report concluded that Christmas Island's biodiversity is 'unlikely to be matched by any other small island in Australia or any other national park in Australia'. But the report also raised concerns about the future, given that four of the island's five endemic mammal species are now extinct, seven endemic plant species have been lost forever, and the remaining populations of endemic reptiles are in rapid decline.
In response to the biodiversity audit, a Christmas Island Expert Working Group published a report (2) in September 2010, which asserted that 'the conservation problems on Christmas Island are pervasive, chronic and increasing and, unfortunately, will not have simple solutions.'
Unfortunately, as the Expert Working Group pointed out, the island's national park recovery and conservation management plans have been poorly implemented, if at all, and have proved inadequate. A lack of staff and funding, combined with the island's complex governance--which includes various federal, state and private agencies--has further hindered conservation management efforts.
Phosphate mining impacts
The Christmas Island phosphate mine has had the greatest single impact on biodiversity. Since mining for phosphate--widely used in fertilisers--began in the 1890s, around a quarter of the island's rainforest has been cleared. Abandoned mine areas are barren and infested with introduced weeds.
To address this problem, Parks Australia has established the Christmas Island Minesite to Forest Rehabilitation Program, aimed at restoring natural vegetation in previously mined leases. According to Christmas Island National Park Manager, Mr Mike Misso, the program has been a success. …