International collaboration demonstrates catastrophic extinction of biodiversity in Hawai‘i and globally
Hawai‘i has been called the “extinction capital of the world.” But, with the exception of the islands’ birds, there has until now been no accurate assessment of the true level of this catastrophic loss. Invertebrates (insects, snails, spiders, etc.) constitute the vast majority of the species that make up Hawai‘i’s formerly spectacularly diverse and unique biota. A team of researchers, including members of PBRC, recently published the first rigorous assessment of extinction of invertebrates in Hawai‘i in the journal Conservation Biology.
The team focused on the most diverse group of Hawaiian land snails, the Hawaiian endemic family Amastridae, of which 325 species have been recognized. The researchers determined that only 15 of these species could still be found alive, and estimated that the rate of extinction may have been as high as 14 percent of the fauna per decade, although more conservatively around 5 percent.
In a companion study published in the Proceedings of the National Academy of Sciences, members of the team, in collaboration with mathematics and bioinformatics specialists at the Pierre and Marie Curie University in Paris, addressed invertebrate extinction globally.
Since the 1980s, many biologists have concluded that the earth is in the midst of a massive biodiversity extinction crisis caused by human activities. Yet only around 800 of the planet’s 1.9 million known species are officially recorded as extinct on the International Union for the Conservation of Nature (IUCN) “Red List”. Skeptics have therefore asked, “Is there really a crisis?”
The research showed, based on extrapolation from a random sample of land snail species from all over the world, and via two independent approaches, that 7 percent (130,000 extinctions) of all the animal species on Earth have already been lost. This loss far exceeds the number reported as extinct on the IUCN Red List. The IUCN’s number is based primarily on assessments of birds and mammals and essentially excludes invertebrates, even though invertebrates constitute roughly 99 percent of known biodiversity.
These studies confirm that the biodiversity crisis is real and is especially acute in Hawai‘i. The also stress the critical need to include assessments of invertebrates in order to obtain a more realistic picture of the current situation, known widely as the “sixth mass extinction.
The research has attracted significant media attention locally, nationally and internationally, including the following, as well as numerous blog postings and Tweets.
Washington Post, 11 August 2015
Huffington Post, 11 August 2015
Le Monde, 26 June 2015
PBRC participants in the studies were: Robert Cowie (PBRC), Norine Yeung (PBRC and Bishop Museum, Honolulu), Kenneth Hayes (Howard University, Washington DC, and PBRC affiliate), and Carl Christensen (Bishop Museum and PBRC affiliate).
French participants were: Claire Régnier and Philippe Bouchet (Muséum national d’Histoire naturelle and Université Pierre et Marie Curie, Paris), Benoît Fontaine (Muséum national d’Histoire naturelle), and Guillaume Achaz and Amaury Lambert (Université Pierre et Marie Curie).
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Régnier, C., Bouchet, P., Hayes, K. A., Yeung, N. W., Christensen, C. C., Chung, D. J. D., Fontaine, B. and Cowie, R. H. (2015).Extinction in a hyperdiverse endemic Hawaiian land snail family and implications for the underestimation of invertebrate extinction. Conservation Biology. doi: 10.1111/cobi.12565
Régnier, C., Achaz, G., Lambert, A., Cowie, R.H., Bouchet, P., and Fontaine, B. (2015). Mass extinction in poorly known taxa. Proceedings of the National Academy of Sciences of the United States. doi: 10.1073/pnas.1502350112