Crunching Numbers | 20,000

The number of species to be assessed by the first global study of the extinction threat to marine life. Think about the species that human activity is pushing to extinction today, International Day for Biological Diversity

["Numbers rule the universe," Greek philosopher and mathematician Pythagoras said. For the month of May, 13.7 Billion Years will reprise the theme from September 2010, presenting a new number to think about each weekday with the series Crunching Numbers.]

The Global Marine Species Assessment project is the first global review of the threat of extinction for every marine vertebrate species, plants and selected invertebrates, currently underway and conducted by the IUCN Species Programme Marine Biodiversity Unit. It began in 2005.

Though it is estimated that there are between 250,000 and one million marine species, this assessment is targeting some 20,000 species believed to be at some level of risk.

The upcoming workshop will be held in July in Dakar, Senegal, and will assess 350 species of West African shore fishes.

Today is International Day for Biological Diversity, set by the United Nations. This year's theme is marine biodiversity, which has been challenged by a host of human causes, such as overfishing (bluefin tuna, a sushi favorite, is on the edge), pollution, climate change and ocean acidification.

In honor of International Day for Biological Diversity, ARKive.org put together some awesome photos of marine species. Also, check out these 13 threatened animals of the ocean.

"From 1980 to 2008, an average of 52 species per year moved one category closer to extinction on the International Union for Conservation of Nature’s Red List of Endangered Species—a rate that shows no signs of slowing," according to Worldwatch Institute.

"Although mass extinctions have occurred on Earth throughout geologic time, the current loss of biodiversity is the first to be caused overwhelmingly by a single species: humans."

• How will you celebrate International Day for Biological Diversity? [add comment]
• Do you avoid eating animals that are endangered, like bluefin tuna? [add comment]
• Are you at all concerned about the staggering loss of biodiversity, and if so, how has that affected your life? [add comment]

ACTION ALERTS

• Check out 10 easy things you can do at home to protect endangered species (Endangered Species Coalition)
• Thinking about a diet that doesn't mean killing animals? Get a free vegetarian/vegan starter kit and take the "Pledge to Be Vegan for 30 Days" (PETA)
• Follow 13.7 Billion Years on Twitter

PAST SERIES

• Ars Animalis: Looking at animals throughout the history of art
• Women's History Month: Remembering 22 women in science
• Purity Month: Looking at 100%
• Instead of This, Try This: Starting the new year with change
• Victory Month: Celebrating positive change through grassroots action
• Of Rice and Men: Cooking the world's most important grain for human nutrition
• 21 Days, 21 Reasons, 21 Recipes, 21 Quotes: Eating plants, loving animals
• Rich Dog, Poor Dog: Considering man's best friend
• Physicists & Priests: Looking at the relationship of science and religion
• Deep Space: Staring at the stars
• Gray Matters: Thinking about thinking
• Flower Power: Stopping to smell the angiosperms
• Animal Cruelty: Looking at the devil within
• Chemical Month: Exploring the vast laboratory of our daily lives
• Africa Month: Visiting the world's second-largest continent
• Reports from 2050: Imagining the future

image: Baby leatherback sea turtle, a critically endangered species (credit: Dtobias, Wikimedia Commons)