24 August 2011 - How many species


Embargo: 5 pm US Eastern Time / 9 pm GMT, Tuesday 23 August 2011

Contacts: Mr. Terry Collins, +1-416-878-8712; +1-416-538-8712; tc@tca.tc

Ms. Darlene Trew Crist, +1-401-295-1356; +1-401-952-7692; darlene.crist@cox.net

Media Resources (downloadable at http://www.soc.hawaii.edu/mora/PressRoom.html; username:

mora_species, password: 7ey9 ): High-resolution still images, the full paper being published by PLoS Biology, and the accompanying commentary by Lord Robert May of Oxford. Audio sound bites for radio (in English and Spanish, with transcripts) may be downloaded at http://bit.ly/ovfqKw


Most precise estimate ever is based on novel, validated analytical technique; Yet to be discovered, described, catalogued: 91% of marine species, 86% of species overall

Eight million, seven hundred thousand species (give or take 1.3 million).

That is a new, estimated total number of species on Earth -- the most precise calculation ever offered -- with 6.5 million species found on land and 2.2 million (about 25 percent of the total) dwelling in the ocean depths.

Announced today by Census of Marine Life scientists, the figure is based on an innovative, validated analytical technique that dramatically narrows the range of previous estimates. Until now, the number of species on Earth was said to fall somewhere between 3 million and 100 million.

Furthermore, the study, published today by PLoS Biology, says a staggering 86% of all species on land and 91% of those in the seas have yet to be discovered, described and catalogued.

Says lead author Camilo Mora of the University of Hawaii and Dalhousie University in Halifax, Canada: "The question of how many species exist has intrigued scientists for centuries and the answer, coupled with research by others into species' distribution and abundance, is particularly important now because a host of human activities and influences are accelerating the rate of extinctions. Many species may vanish before we even know of their existence, of their unique niche and function in ecosystems, and of their potential contribution to improved human wellbeing."

"This work deduces the most basic number needed to describe our living biosphere," says co-author Boris Worm of Dalhousie University. "If we did not know -- even by an order of magnitude (1 million? 10 million? 100 million?) -- the number of people in a nation, how would we plan for the future?"

"It is the same with biodiversity. Humanity has committed itself to saving species from extinction, but until now we have had little real idea of even how many there are."

For the full media release, go to: