In Mapuche mythology, the souls of dead people travel west to visit this island.

According to Juan Ignacio Molina, the Dutch captain Joris van Spilbergen observed the use of chilihueques (a South American camelid) by native Mapuches of Mocha Island as plough animals in 1614.

The waters off the island were inhabited by sperm whale, including Mocha Dick, who was depicted by American explorer and author Jeremiah N. Reynolds in his published account, "Mocha Dick: Or The White Whale of the Pacific: A Leaf from a Manuscript Journal" in May, 1839 in The Knickerbocker magazine in New York.

[3] In December 2007 several human skulls with Polynesian features, such as a pentagonal shape when viewed from behind, were found lying on a shelf in a museum in Concepción.

The island has been designated an Important Bird Area (IBA) by BirdLife International because it supports significant populations of pink-footed shearwaters, Peruvian pelicans, red-legged cormorants and elegant terns.