The next in the island series is the Galápagos Islands which have a unique set of species that have evolved in isolation from other species. This wildlife has become under threat from many thousands of tourists who, ironically, come to admire it.
Straddling the equator, the Galápagos Islands have a unique ecosystem and are situated in the Pacific Ocean 926 km (575 mi) west of Ecuador. The islands are an archipelago that consist of 18 main islands and some smaller ones. The islands are volcanic and exist above the Galápagos hotspot. A hotspot is a volcanic region that is anomalously hot compared with the mantle elsewhere and is thought to be fed by the underlying Earth’s mantle. In the case of the Galápagos the hotspot may be fed by mantle plumes that bring magma to the surface and sustain volcanic activity. The islands are located very close to the spreading ridge between the Cocos and Nazca tectonic plates which explains their volcanic origins.
The Galápagos Islands are an excellent example of islands that have a very rich set of species that have evolved in isolation. The theory of island biogeography is a field within biogeography that examines the factors that affect the species richness of isolated natural communities; it is used in reference to any ecosystem surrounded by unlike ecosystems. The origin of the theory dates from the 1960s. It was two ecologists (Robert MacArthur and E.O. Wilson) who invented the term island biogeography. It was Charles Darwin who, on the Voyage of the Beagle, in the 1830s who identified such an unusual and unique species on the islands. Species include iguana, the booby seabird, the Galapagos Hawk, and giant tortoise amongst many others. There is a Galápagos marine iguana which is the world’s only sea-going lizard.
The geology has directly affected the species present on each island. The hotspot is situated below the westernmost islands of Fernandina and Isabela, which are the youngest islands (about 1 million years old). They still have active volcanoes. The Nazca plate is moving in a South East direction is gradually moving the other islands away from the source of vulcanism. When this happens volcanoes become extinct although a new volcano is created under the hot spot. The Galápagos Islands form a chain of islands that are progressively older and more eroded to the southeast. The southeastern islands are 3 to 4 million years old and have had more opportunities to be colonised by life than the more recent islands. Life has evolved more so there.
Today the islands that are host this unique set of wildlife are under threat from humans who come to visit the islands and introduced species. There are more than 160,000 tourists each year who visit the islands; the tourism boom has meant that the local population has also grown significantly from around 3,000 in the 1960s to about 30,000 in 2012. This growth in tourism has presented a threat to the ecosystems as more people arrive to service the tourist’s needs.
In 1998, the Ecuadorian government enacted the Galápagos Special Law, a legal framework to protect the Galápagos and its unique ecosystems. The World Wide Fund for Nature is helping to manage the unique ecosystems. Their work is detailed on there web site. They see the solution in tourism becoming a tool for conservation and sustainable development.
The Galápagos is an international treasure and it is important that the area is managed in a sustainable manner. Growth in tourism and the local population have started to introduce a number of issues that are a threat to the unique wildlife. Carefully management is the answer here to ensure that the wildlife is protected from threats from mankind and introduced species that will affect or destroy the indigenous species.
For details of the wildlife of the islands see this link: http://www.rutahsa.com/gal-anim.html