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Deep Under Sea, New Species Seen E-mail
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Sunday, 12 August 2007
Deep Under Sea, New Species Seen


Daily Press (Newport News, VA)

By Matt Sabo


Dodging ice floes in the Antarctic pays off for a VIMS professor with hundreds of discoveries.

At depths of more than three miles under the Antarctic sea, in utter darkness under bone-crushing pressure in water as cold as 28 degrees, a professor at the Virginia Institute of Marine Science in Gloucester, is among a handful of scientists who discovered hundreds of new species.

The sea and sediment was rich with animals that include meat-eating sponges, worms, crustaceans and mollusks -- more than 700 new species altogether.

Robert Diaz, who has been teaching and researching at VIMS for 35 years, said sediment core samples yielded about 580 new species of isopods, little critters related to pill bugs a gardener might find in soil around tomatoes. Another 120 new species of polychaetes -- related to earthworms -- were found.

Diaz said the team's most significant finding is the unexpected vitality and diversity of the seafloor community in such a harsh environment.

Aside from the oily darkness and the cold is the pressure -- at some depths the weight of three miles of seawater.

"Immense pressure," Diaz said. "So much so that a lot of species can't survive at lower pressure."

The water hasn't solidified because of the salinity and pressure, Diaz said. When some of the species are brought up from the depths, their molecules deform.

"They're evolved to deal with the specialization, to deal with the pressure and no light," Diaz said. "It was all just incredibly interesting."

He was part of an international research team that journeyed to the bottom of the world to explore the deep sea around Antarctica. Their discoveries suggest the creatures in the deep water are likely related to animals living in nearby shallower waters and in other areas of the deep ocean.

One of the questions for the scientists is whether the species living in shallow water colonized the deep ocean or vice versa. Their research indicates that as the Antarctic ice advanced, it might have forced organisms from shallow waters into the surrounding deep ocean.

That led to an intermingling of species originating in shallow and deep-water habitats.

The Antarctic deep sea is potentially the cradle of life of global marine species, said Angelika Brandt, a professor from the Zoological Institute and Zoological Museum at the University of Hamburg in Germany. Brandt is the lead author in a report covering the discoveries in this week's journal Nature.

"Our research results challenge suggestions that deep-sea diversity in the Southern Ocean is poor," she said. "We now have a better understanding of the evolution of marine species and how they can adapt to changes in climate and environments."

The team traded shifts on a 400-foot ship that cruised the ocean below South America and South Africa during the Antarctic summer -- where an average day consists of temperatures just above freezing with winds of 30 to 40 miles per hour.

"It might snow, it might rain," Diaz said, "and the captain is dodging ice floes the whole time."

For the scientists, it's monotonous work punctuated by moments of excitement.

"For me," Diaz said, "the most exciting part was seeing the photographs for the first time."

In addition to photographs, the team took core samples of sediment. Diaz was surprised at the degree to which animals are rooting through and mixing sediment in the deep ocean. It's similar to what would be found in the relative shallows of the Chesapeake Bay, he said.

Katrin Linse, a marine biologist from the British Antarctic Survey, said what was once "thought to be a featureless abyss is in fact a dynamic, variable and biologically rich environment. Finding this extraordinary treasure trove of marine life is our first step to understanding the complex relationships between the deep ocean and the distribution of marine life."

Diaz and the other scientists are working on the Antarctic benthic deep-sea diversity project, which consisted of three expeditions to the Southern Ocean -- also known as the Antarctic Ocean -- from 2002 to 2005 aboard a German research ship.

The international team consisted of members of 14 research organizations who investigated the seafloor to try to understand life in that region of the ocean. In addition to Diaz, VIMS graduate student Lawrence Carpenter also took part in the research.

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