Officials at Ecuador's Galapagos National Park say they have collected 22 tonnes of garbage since January off the coasts of the pristine archipelago, some of it from as far away as Asia.

The coastal garbage cleanup is aimed at studying "the possible arrival of invasive species in the waste swept in by the ocean currents," the Park said in a statement late Saturday.

The Galapagos, the Pacific archipelago of volcanic islands that inspired Charles Darwin's theory of evolution, are located about 1,000 kilometers (600 miles) off the coast of Ecuador.

The bulk of the garbage reaches the island shores "from the coasts of Central and South America, and even from the Asian continent," the statement said.

The national park, created in 1959, protects 97 percent of the islands' land surface.

The Galapagos has an especially high concentration of endemic species, including giant tortoises and penguins. In 1978 Unesco classified the islands as a World Heritage Site.