The photic zone is an area of the ocean that extends beyond the reach of sunlight, as deep as 5,000 meters. For the first time, a serious effort has begun to try and catalogue the vast array of deep sea life, under the auspices of the Census Of Marine Life (COML). Currently, they've identified more than 17,000 species inhabiting the dark depths, which will join with information from hundreds of other projects next October to reveal the complete results of the census.

Most of these creatures survive on marine snow—particles of decaying plants and animals that descend to the ocean floor. This transparent sea cucumber was found at 2,750m, creeping forward at a rate of 2 cm per minute, sweeping detritus into its mouth.

[via COML]

Photos courtesy of Larry Madin, Woods Hole Oceanographic Institution.

The tiny copepod, from the Atlantic.
Image © Büntzow/Corgosinho

One of the dumbo octopods, which can grow up to five feet in length.
Photo by David Shale



The jewel squid has tiny light organs all along its body, which emit and perceive light.

This is only the fifth ever found Neocyma, discovered between 2,000 and 2,500m. Image from David Shale.

The northern comb jelly has oscillating lights up and down its length.



The snake pipefish

The "wildcat" tubeworm, which drills for oil, then dines on the chemicals inside when it hits a small well.

It wouldn't be the deep sea without nightmare fuel. Like the loosejaw, with its extendible lower jaw and red-light sensitive eyes.

Or the swallower.

Making a list of marine species might not seem like a big deal, but taxonomists face some daunting problems. For one thing, some species have dozens of names, nicknames and even "official" Latin names dating back centuries. The Census of Marine Life is sorting through all of them and figuring out which species are which, assigning them scientific names, and noting all of their aliases. To make matters worse, researchers are constantly finding new species, sometimes hundreds at a time. It can take years for a new find to be published because of the taxonomic chaos.

The Census is working with the World Register of Marine Species to clear all this up. They currently have over 120,000 validated names, and expect to top 200,000 by the end of this year. What's truly astonishing is their estimate for the total marine species on Earth, discovered and undiscovered: over 1 million. At the current rate of progress, it would take over 500 years to catalog all of them. As more and more species are threatened by pollution and climate change, it becomes even more important to identify them.

Ultimately, the Census of Marine Life catalog will be used to build the Ocean Biogeographic Information System (OBIS). This information portal will have photographs, distribution info and a ton of other data on each species, all easily accessible and updatable. Census data will also be contributed to the Encyclopedia of Life and the Species2000 project, which will create a similar catalog for every single species on our planet - animal, plant, fungi...everything. Image by: NOAA.

Census Of Marine Life Lists 122,500 Known Species, Over Halfway To Complete Inventory By Oct. 2010. [Science Daily]