The secrets of the underwater world have always been a challenge for scientists trying to connect the past, the present and the future of the marine species living here. During the World Conference on Marine Biodiversity to be held in Valencia, Spain on November 11-15, over 700 scientists from the Census of Marine Life community will report their progress on the first ever marine life census, which is expected to be released in 2010.

Speaking of past, present and future, the marine scientists have managed to link most of the deep sea octopus species we see today to a common Antarctic ancestor, which surprisingly enough, can still be found in the Southern Ocean. The findings are based on what was reported as the first molecular evidence to support that link.

Scientists revealed that 30 million years ago, octopuses living in the Antarctic water started migrating, as their habitat began cooling and the ice sheet grew, forcing them to occupy new ocean basins. But as they started migrating, the conditions they met in the new habitats triggered evolution differences in octopus species.

Explorers believe the octopuses followed the “Antarctic thermohaline expressway,” a northbound flow rich in oxygen and with a high salt density caused by the ice that forms at the surface around the Antarctic, the water cascading like cream.

There are approximately 300 recognized species of octopus living in world’s oceans, but their adaptive biology clearly differentiates them. Some species, for example, have lost their famous ink sacs (used as a defense mechanism) due to the fact that in the dark depths they live in, this particular decoy would be useless. More details on this report will be offered in the November 11 issue of Cladistics.

“The impressive number of landmark findings over the past two years reveals the richness of what remains to be discovered,” said deep-sea explorer Myriam Sibuet, vice-chair of the Census. “The vastness of the ocean and our new research tools keep marine biology forever young.”

Among the missions of the Census project, scientists are sampling along the Mid-Atlantic Ridge at depths down to 2,500 meters to find hundreds of rare or unknown species, or exploring the world’s deepest known active hot vent at over 4,100 meters depth, populated by anemones, polychaete worms and shrimps.

Researchers are also looking into the Black Sea bacterial mats that use methane as energy source, forming spectacular chimneys of up to four meters high. “Such reefs could contribute key insights into mechanisms controlling emissions of methane, and important greenhouse gas, from the ocean to the atmosphere,” scientists explained.

From the coast of New Zealand, to the shores of the Alaskan Arctic, to the Pacific and the Philippines, scientists are providing new insights into ocean biodiversity, the effects of human activities on marine life, and more, with the purpose of establishing a solid foundation for scientifically-based policies.

Ian Poiner, chair of the Census International Scientific Steering Committee and Chief Executive Officer of the Australian Institute of Marine Science, called the release of the Census in 2010 “a milestone in science,” as a result of 10 years of hard work from thousands of experts across the globe. The Census “will synthesize what humankind knows about the oceans, what we don’t know, and what we may never know – a scientific achievement of historic proportions.”