The fauna and flora of the Galapagos Archipelago is unique because of extreme isolation from other land masses. The archipelago lies more than 1,000 km off the shore of mainland Ecuador and all its islands are oceanic, meaning that they have never been connected to the continent. They are volcanic in origin and rose from the sea floor, emerging as bare rocks to become colonized by plants and animals, which were able to cross the immense distance from the continent, endure the passage across the sea, and survive.
Many species that arrived in Galapagos encountered a harsh, dry environment and only the ones well adapted survived. Those capable of tolerating the hostile conditions had the advantage of living in an environment with little competition. These newcomers diversified and evolved to adapt to an environment inhabited by few predators parasites or diseases. In their recently conquered home the new arrivals thus became ancestors of species that today are unique to Galapagos. A large proportion of the Galapagos species are endemic. This means they are only found here and live nowhere else in the world.
Today the archipelago is no longer isolated. The evolutionary processes responsible for the natural diversity of life on these islands have been disturbed. Each day new species are introduced either on purpose or accidentally as a result of human activity. Native species, having evolved over thousands of years, well protected by isolation, are badly prepared for recent introductions of competitors, predators, pests and parasites. These alien species are considered a principal threat to the conservation of the Galapagos Islands and in conjunction with habitat loss now regarded of the leading causes of species extinctions worldwide.
The phenomenon is not unique to Galapagos. Islands generally support high numbers of endemic species that evolved as a result of geographical isolation and are therefore extremely vulnerable to introduced, alien newcomers. Across the Pacific many islands were originally characterized by a diversity as unique as the one in Galapagos. Today, however, most islands have suffered enormous biodiversity loss as a result of biological invasion by introduced species.
Galapagos has been hailed as one example where biodiversity loss has been less drastic. For centuries they remained undiscovered and undisturbed. They were discovered fairly late (only 500 years ago Bishop de Berlanga stumbled across the archipelago by accident). Even after their discovery their harsh environment was uninviting and for a long time the islands remained unattractive for human settlement.
Today this has changed. A tourist industry is now thriving; planes and boats bring in people and goods every day, and along with them come new, unwanted species would have never been able to reach the islands by natural means. For the Galapagos quarantine service up-to-date knowledge of these introduced species and of high threat species that are likely to arrive is as important as it is fascinating to know which species naturally occur here. Therefore the CDF Galapagos Species Checklist here also includes lists of introduced species and pathogens.
Editors: Mark Gardener, Charlotte Causton, Rachel Atkinson, Anne Guézou.
Collaborators: Galapagos Biosecurity Agency and Galapagos National Park Directorate.
You are welcome to download and use this information acknowledging the origin of the data.
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