snail habitat
Native Hawaiian snail habitat on Pu'u Kukui, Maui. Reuters/Robert Cowie, PBRC

New research has charted the impact of a catastrophic extinction event taking place among Hawaii’s invertebrate population, showing how over 10 percent of the island’s fauna may have gone extinct each decade since as early as the 1600s. Another study on the world's population of invertebrates reached a similar conclusion.

A team of researchers from the University of Hawaii at Manoa, the Bishop Museum in Honolulu, Howard University in Washington D.C., and the French National Museum of Natural History in Paris conducted a survey of the extinction of invertebrates in Hawaii, focusing on the most diverse group of Hawaiian land snails, known as family Amastridae, which currently boasts 325 endemic species. They found that only 15 of these species may still be alive, which would mean that the extinction rate may have been as high as 14 percent per decade, according to a press release Monday. The results of the study were published in Conservation Biology.

In a companion study published in the Proceedings of the National Academy of Sciences, the same team charted invertebrate extinction across the planet. Analyzing land snail populations across the world, the researchers found that the planet may have lost up to 7 percent of all animal species on Earth.

That number significantly exceeds the rate of global loss of biodiversity reported by the International Union for the Conservation of Nature’s (IUCN) "Red List," which is a projection based on bird and mammal populations. The team criticized the IUCN's method, pointing out that invertebrates constitute 99 percent of all known biodiversity.

The researchers said that their results mean that anthropogenic extinction, a phenomenon known as the “sixth mass extinction,” may be far more severe than previously thought. Scientists have already warned that the extinction rates of vertebrates is moving about 100 times faster than previously thought -- “a global spasm of biodiversity loss” that could take “millions of years to recover,” Gerardo Ceballos of the Universidad Autónoma de México warned in a June study.