Pablo Ospina,
Coordinator of the WWF-Fundacion Natura monitoring project for Galapagos.
World Conservation 4/97-1/98
The introduction of large numbers of exotic species-and the spread of those which prove to be exceptionally aggressive-has an impact not only on the management of populations of native and endemic species of the Galapagos, but also on the preservation of the evolutionary process of the islands.
Aggressive plants
To date more than 460 introduced plants have been documented. Ecuador's Ministry of Agriculture has examined the extent to which the agricultural zones have been affected by invasive plants, and its data give an indication of the magnitude of the problems posed by rapidly spreading invasive plants such as the guava Psidium guajava, the quinine Cinchona succirubra and the sauco Cestrum auriculatum, among others. The percentage of agricultural land affected by invasive plants is at least 22% for Isabela, 21% for San Cristobal, 17% for Floreana and 12% for Santa Cruz. The consequences for native flora become evident when Parkland is included. Although no complete inventory has yet been made, observers estimate that at least the guava alone covers 50,000ha of park and agricultural land.
A public call for quarantine
Since 1994 a Regulation for the installation of a System of Inspection and Quarantine of the Galapagos Islands (SICGAL) has been in effect. The system has been slow getting started and lacks sufficient funds. The Charles Darwin Research Station launched a public awareness campaign to promote the quarantine and has begun a pilot project for the initiation of the work of SICGAL. A Technical Secretariat in the Galapagos was established, made up of a representative from the Charles Darwin Research Station (CDRS), two representatives from the Galapagos National Park Service, a representative from the Galapagos National Institute and a local representative from the Agricultural Ministry, with the latter presiding. Inspections commenced in September 1997 in the port of Puerto Ayora and the airport at Baltra, and are due to commence in Guayaquil in 1998.
A plague of goats
The Galapagos National Park Service (SPNG) has a long-established program to eradicate introduced mammals. Thanks to the efforts of the Park and with the support of the CDRS, over the last 30 years goats have been eliminated from five islands of the archipelago: Espanola, Plaza Sur, Santa Fe, Marchena and Rabida. However, goats are present in enormous numbers on Isabela, owing to a recent (1994-1997) population surge against which intensified hunting efforts had little effect. It will require an especially vigorous campaign to rid the islands of these pests, which threaten the island's renowned giant tortoises. The task is complicated by the sheer number of goats-roughly 100,000 animals-and the conditions on the islands: Isabela is 20 times the combined size of the other five islands mentioned, and most of it is extremely rugged volcanic terrain. Nevertheless, the Ministry of Environment, the National Park Service and the CDRS consider the eradication of goats and donkeys from the northern half of Isabela a priority, and will solicit funds from the Global Environment Facility for part of the cost of a project to carry this out. As a sideline, the project will also complete the eradication of goats on Pinta Island. Santiago, with some 50,000-100,000 goats, has a similar problem remaining to be addressed.
The integrity of the ecosystems of the Galapagos depends to a great extent on the success of these campaigns for mammal eradication and the quick implementation of an efficient system of inspection and quarantine.