Historic Marine Life Census Counts Over 250,000 Species

marine census venus flytrap plant

Photo Credit: I. MacDonald

Back in February, we were excited to know that the Census of Marine Life -- a massive undertaking of accounting for all live in the ocean -- had started to wrap up. But details on findings were still under wraps. Just yesterday the researchers finally released a report of the marine life found in 25 key areas of the world, with over 10,000 species in each area. After combining information collected over centuries and during the past decade through the census project, this census is the most comprehensive tracking of what lives in the sea to date. From the Antarctic to the Arctic and everything in between, check out what lives in the seas. The census will help researchers determine where and what has been a neglected part of marine research, and figure out which areas and what types of animals need to be examined more. So far, Australian and Japanese waters, and those of China, the Mediterranean and the Gulf of Mexico, are the most biologically diverse in known species. However, other areas are also highly diverse and scientists are still taking inventory in places like Indonesia, Madagascar and the Arabian Sea.

census slug image

Images via Census of Marine Life project

Still, the project has revealed that the known, named species in the 25 areas studied average around 10,750 per area. Here's the breakdown on types of species:

* 19% Crustaceans (including crabs, lobsters, crayfish, shrimp, krill and barnacles),
* 17% Mollusca (including squid, octopus, clams, snails and slugs)
* 12% Pisces (fish, including sharks)
* 10% Protozoa (unicellular micro-organisms)
* 10% algae and other plant-like organisms
* 7% Annelida (segmented worms)
* 5% Cnidaria (including sea anemones, corals and jellyfish)
* 3% Platyhelminthes (including flatworms)
* 3% Echinodermata (including starfish, brittle stars, sea urchins, sand dollars and sea cucumbers)
* 3% Porifera (including sponges)
* 2% Bryozoa (mat or 'moss animals')
* 1% Tunicata (including sea squirts)

Also, 5% are "other invertebrates and 2% are other vertebrates, which include whales, sea lions, seals, seabirds, turtles and walruses. Some of the species are found in many of the studied areas -- called "cosmopolitan," they include algae, protozoa and copepod in plankton, and the manylight viperfish which has been recorded in a quarter of the planet's marine areas. Also, seabirds and marine mammals that migrate all their lives are considered cosmopolitan.

Quiz: Know Your Marine Life?

The types of species most common to an area varies. For example, crustaceans like crabs, lobsters and shrimp make up 22% to 35% of species for Alaska, Antarctica, Arctic, Brazil, California, Caribbean, and Humboldt regions, but only 10% for the Baltic. Similarly, Mollusks like clams and squid make up 26% of the species in Australia and Japan, but only 5% to 7% of the species in the Baltic, California, Arctic, and eastern and western Canada. Seeing these breakdowns illustrates why sustainable seafood menus vary by area -- what is sustainable on the west coast isn't sustainable on the east coast.

census fish photo

Mark Costello of the Leigh Marine Laboratory, University of Auckland, New Zealand, the lead author of the study, states, "Sparse, uneven marine sampling in much of the world underlies this initial inventory, and future research will undoubtedly alter the profile presented today.

"This inventory was urgently needed for two reasons. First, dwindling expertise in taxonomy impairs society's ability to discover and describe new species. And secondly, marine species have suffered major declines -- in some cases 90% losses -- due to human activities and may be heading for extinction, as happened to many species on land."

Similar to the highly unique species on land, New Zealand and Australia, as well as the Antarctic and South Africa have the most endemic species, or species entirely unique to that area. On the flip side, the Mediterranean has the most invasive species living in its water, though the European Atlantic, New Zealand, Australian Pacific and Baltic waters are also seeing many invasive species.

census urchins photo

Still, all this research is not complete. In October, the researchers will release the latest estimate of all marine species known to science, beyond just these 25 key areas. The "final" count will likely remain just a scratch on the surface.

Check out this amazing interactive map of the project, which shows you what has been studied and where.

census map image

"At the end of the Census of Marine Life, most ocean organisms still remain nameless and their numbers unknown," says renowned biologist Nancy Knowlton of the Smithsonian Institution, leader of the Census' coral reef project. "This is not an admission of failure. The ocean is simply so vast that, after 10 years of hard work, we still have only snapshots, though sometimes detailed, of what the sea contains. But it is an important and impressive start."

It is indeed impressive. Marking out what lives where and in what numbers can give us all a far clearer sense of what impact issues like overfishing, habitat loss, and pollution are having on ecosystems and the flora and fauna living in them. Many species may be lost before they even have a chance to be counted. In fact, look at this map from the census on the change in species density in just 30 years:

species density map image

"We must increase our knowledge of unknown biodiversity more quickly, lest much of it is lost without even being discovered," says Dr. Miloslavich. "International sharing of data, expertise and resources, as has been accomplished through the Census of Marine Life, is the most cost-effective way of achieving this."
National Geographic shows off this video featuring many of the newly discovered species:

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More on Marine Life Discoveries
5,000 Amazing New Undersea Species Discovered in Marine Census (Pics)
Historic Images Document Drastic Depletion of Marine Life (Slideshow)
First-Ever Animals Found Living Without Oxygen in Marine Dead Zone

Historic Marine Life Census Counts Over 250,000 Species
Back in February, we were excited to know that the Census of Marine Life -- a massive undertaking of accounting for all live in the ocean -- had started to wrap up. But details on findings were still under wraps. Just

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