The U.S. Census was not the only enumeration completed this year. The Census of Marine Life, an unprecedented collaboration of 2,700 scientists from 81 countries culminated in 2010 after ten years, and more than 540 ocean expeditions. And the results are staggering. The Census documented a changing ocean, richer in diversity, more connected through distribution and movement, more impacted by humans, and yet less understood than previously believed.

Researchers asked three basic questions: What lives is the global ocean?, Where do they live?, and How Many are there?

More than 6,000 new species were discovered, and the estimate of known species increased from 230,000 to 250,000, as genetic analysis revealed that organisms thought to be related were in fact different species. Extrapolating from that, scientists estimate that the total number of marine species is close to one million – meaning that another 750,000 have yet to be found.

Life was found everywhere researchers looked, from temperatures high enough to melt lead to those low enough to freeze seawater, and in places where oxygen was absent. Although the ocean may look uniform from above, these habitat extremes were the norm rather than the exception. Migratory routes and feeding and breeding areas were mapped, showing how interconnected the ocean basins are. Scientists explored parts of the deep sea and sea floor never before seen by human eyes, and found life thriving on ocean ridges, seamounts, abyssal plains, continental margins, and hydrothermal vents.

This Hydrothermal vent snail, Alviniconcha sp. from the Suiyo Seamount, Tokyo Hydrothermal Vent is the only specimen ever found. Photo Credit: Yoshihiro FUJIWARA/JAMSTEC

While the number of species is high, the abundance and size of many of them are decreasing. From the plankton at the base of the food chain to the predators at the top, species are in decline. Since the 1950s, phytoplankton abundance has decreased by 40%. Overfishing and habitat destruction are the leading direct threats to marine life.

Census researchers also discovered things about humans, dividing the causes separating the known from the unknown and the unknowable into five categories:

1. the invisibility of the parts of the past that have been lost;
2. the vast expanse of the ocean;
3. the challenges in assembling knowledge of parts into an understanding of the whole;
4. events and disturbances that we can’t predict, such as tsunamis, and
5. the blinders we put on ourselves by choosing not the look or spend the time or money to know.

I have just started to plumb the depths of the papers, presentations, briefings, photos, and maps produced by this unprecedented scientific collaboration. Over the next few months, I will feature a number of posts highlighting the most exciting Census discoveries. In the meantime, I urge you to check out the fabulous resources available for free on their website. Some personal favorites are (so far):

• Detailed maps of the Distribution, Diversity and Abundance of marine life, and the Past, Present, and Future of life in the oceans, produced by National Geographic Society,
• A video gallery of short films of marine life from the equator to the poles, including whales, Great White sharks, coral reefs, deep sea creatures, as well as scientists doing and discussing the work of the Census,
• Images, a music video, and an ocean life screensaver (available for Windows and Mac – but not Linux).

Stay tuned for more on the incredible What, Where, and How Many of life in the global ocean.