Urbanization and tourism lead to a massive decline in insects on oceanic islands. This is what researchers from the German University of Bayreuth in the Maldives have found. On the islands with increasing urbanization, they documented an average of 48 percent fewer insect species there than on the uninhabited islands of the archipelago. On the tourist islands it is even 66 percent less, the scientists report in the magazine „Open Science“.
One fifth of life
Oceanic islands only make up a little more than two percent of the earth’s land mass. At the same time, however, they are home to a fifth of all known animal and plant species and around half of all threatened species. “The global extinction of species caused by humans is particularly drastic on oceanic islands in the tropics,” said first author Sebastian Steibl in a statement from his university about the article in the magazine of the British Royal Society.
In the Maldives, the researchers distinguished three types of islands that are close to each other: uninhabited islands, islands inhabited by the local population and islands used for tourism. “On islands used for tourism, it is probably the use of pesticides that mainly causes the drastic decline in insect diversity,” says Streibl. The pesticides are used against mosquitoes, but other species are also affected.
According to the researchers, further investigations must now clarify the long-term consequences of insect death on the island’s ecosystem.