SSC experts search ways to save "Treasure Island" from ravages of invasive species

Gland, Switzerland, 5 April 2004 (IUCN) - Five experts from the Invasive Species Specialist Group of IUCN's Species Survival Commission are investigating ways to eradicate alien invasive species from Costa Rica's Cocos Island National Park, to save the island's unique native biodiversity.

Alan Tye, Brian Cook, Norm McDonald, Michel Pascal and Claudine Sierra all have extensive experience in the management and eradication of alien species in New Zealand, Australia, the Galapagos Islands and other countries. They recently carried out a mission to the island that is a favourite destination for treasure hunters due to legends about great fortunes hidden by pirates, centuries ago.

Invasive alien species are plants and animals that are intentionally or accidentally introduced by people into habitat they could not have reached on their own and then out-compete the native species. Globalisation, particularly through increasing international trade and transport exacerbates the problem. The costs of removing unwanted species are enormous and invasive species are not just an ecological problem but have many social and economic consequences.

Island populations of native plants and animals are particularly vulnerable to the effects of invasive alien species. Hundreds of new plant assessments from Hawaii, the Falkland Islands (Malvinas), British Virgin Islands, the Seychelles, Tristan da Cunha, St. Helena and Ascension in the 2003 IUCN Red List of Threatened Species revealed that many are being pushed towards extinction.

Cocos Island's world-renowned waters feature white tip reef sharks, hammerhead sharks, dolphins, mantas and marbled rays, giant moray eels, sailfish, Creole fish, green turtles and octopus. Its terrestrial life is marked by a high number of endemic species (those found nowhere else) of both plants and animals. There are more than 80 bird species, including the endemic Cocos Island cuckoo, finch and flycatcher.

One of the main threats to Cocos Island National Park are domestic animals that were introduced many years ago including pigs, cats, two species of rat and the white-tailed deer. Rats eat various native plants and animals while pigs cause untold damage through their search for food, destroying the forest understorey. They root up the soil, which is washed away by heavy rainfall, causing erosion and carrying materials into the ocean. The resulting turbidity of the water and sedimentation damage the coral ecosystems that surround the island.

The problem of invasive species on the island has already been studied in depth, and the SSC specialists based their investigation on a project for the eradication of the pigs, rats and cats, designed by biologist Claudine Sierra.

The mission's objectives were to assess the viability and methods of the eradication plan and propose a strategy for managing other invasive alien species. It was promoted by the Cocos Island Conservation Area, under the Ministry of Environment and Energy (MINAE), the Friends of Cocos Island Foundation (FAICO) and IUCN. Funding was provided by the United Nations Education, Science and Cultural Organization (UNESCO) and the French Embassy in Costa Rica.

In a meeting at IUCN's Regional Office in Mesoamerica, the mission scientists and representatives of FAICO and MINAE assured that the methods used to eradicate the invasive mammals would not affect other species on the island, especially certain endemic birds. However, more investigations are necessary.

The meeting included representatives of different sectors, including tourism operators in the zone. A multi-stakeholder approach to the problem is being sought with animal rights groups and institutions such as the National Technical Environmental Secretariat (SETENA), the National Protected Areas System (SINAC), various NGOs, the Coast Guard, and State universities, all being consulted.

The team is now working on a report which will outline the key findings and recommendations.

About the island

* Cocos Island is situated in the Pacific Ocean, 532km from the closest point on the continent, which is Cabo Blanco, on Costa Rica's Nicoya Peninsula.

* The island was declared a national park by the Government of Costa Rica in 1978.

* It was designated a World Heritage Site by UNESCO in 1997.

* In 1998, it was placed on the list of Wetlands of International Importance, under the Ramsar Convention.

* In 2002, Cocos Island was declared part of the Historical Architectural Heritage of Costa Rica.

For more information contact:
Marco A. Calvo F, Communications Officer
IUCN-Regional Office for Mesoamerica
Tel: +506 241-0101; Fax: +506 240-9934
E-mail:; Web:

Work area: 
Invasive species
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