Ongoing Extinction Level Event

One-fifth of invertebrate species are at risk of extinction according to an article in nature magazine this week. According to the piece, "One in five of the world’s invertebrate species are threatened with extinction, according to the latest report from the Zoological Society of London (ZSL). From the checkerspot butterfly to the giant squid, spineless creatures are thought to represent around 99% of biodiversity on Earth. However, until now, scientists have never attempted a comprehensive review of their conservation status. In fact, fewer than 1% of invertebrates had been assessed by the International Union for Conservation of Nature (IUCN), which has listed threatened species on its Red List since 1963." it goes on to "conclude that the greatest threat is to freshwater invertebrates, including crabs and snails, followed by terrestrial and marine invertebrates. More mobile animals, such as butterflies and dragonflies, tended to have the least risk of extinction."

Overall it estimates that 34% of freshwater invertebrates including more than half of the world's freshwater snails and slugs could be under threat: "In the oceans, almost one-third of reef-building corals are endangered largely because of climate change, which causes coral bleaching and ocean acidification."

The report used IUCN metholology and assesed more than 12,000 species.

The IUCN has previously estimated that a similar proportion of assessed species at risk in a November 2009 report entitled "Extinction crisis continues apace" which states that "The latest update of the IUCN Red List of Threatened Species™ shows that 17,291 species out of the 47,677 assessed species are threatened with extinction. The results reveal 21 percent of all known mammals, 30 percent of all known amphibians, 12 percent of all known birds, and 28 percent of reptiles, 37 percent of freshwater fishes, 70 percent of plants, 35 percent of invertebrates assessed so far are under threat.
“The scientific evidence of a serious extinction crisis is mounting,” says Jane Smart, Director of IUCN’s Biodiversity Conservation Group. "