Lively Fish Five Miles Down

Mysteries of the Deep Revealed

Scientists exploring a deep underwater crevasse in the Pacific Ocean known as the Japan Trench were surprised to find an active and sociable group of snailfish at the record depth of almost five miles (7,700 meters).

The remote camera exploration that ended last week was a collaborative effort between the University of Aberdeen and the University of Tokyo under the auspices of the Oceanlab HADEEP Project.  The Oceanlab team built the deep sea equipment that withstood the incredible depth pressure of 8,000 tons per square meter, which is about the equivalent of 1,600 elephants standing on top of a Mini Cooper automobile.

But the greater feat of engineering might be the fish themselves, who thrive in an environment without light and near-freezing temperatures.  Dr. Alan Jamieson of Oceanlab was stunned with the find, saying, “All we’ve seen of life at this depth have been shriveled specimens in museums.  Now we have an impression of how they move and what they do.  Having seen them moving so fast, “snailfish” seems a complete misnomer.”

Some species of snailfish live in shallow water and rock pools closer to the surface, but the hadal snailfish found by this expedition prefer life at 6,000 meters and deeper.  The species eats an abundance of tiny shrimp-like creatures that in turn rely upon the carcasses of dead fish falling to the ocean floor and other debris to support them.

The Oceanlab project is the latest contribution to our scant knowledge about life in the ocean depths.  A recent expedition in the waters off of Australia found 274 species of fish, corals, crustaceans and other sea life more than a mile deep.  Previous explorations have found animals living in the boiling hot water by underwater volcanoes at similar depth ranges of complete darkness. 

The centuries-long fabled giant squid (Architeuthis) was only proven to exist on September 30, 2004 when researchers from the National Science Museum of Japan and the Ogasawara Whale Watching Association first captured images of a live giant squid in nature.

However, as the video to the right shows, there’s still plenty more to be learned.   Although the Architeuthis grows to an estimated 33 feet in length, the squid caught in this footage from the History Channel is estimated to be 60 feet based upon video analysis.  This could be the equally elusive “colossal squid.”

While many believe we know more about the moon than the ocean, the claim is somewhat specious, because it’s impossible to measure what we don’t know.  That can only be gauged by historians after all the facts are in, and it’s clearly not going to be any time soon.  The reason why we may appear to know less about the deep sea is that bottom of the ocean is far more difficult to reach than the moon based upon our current technology, and the moon is a relatively static place compared to the dynamic seas.

This expedition took our observatory capacity to a depth of approximately 4.8 miles, however the Japan Trench is only the sixth deepest trench in the ocean.  The Mariana Trench, also in the Pacific, is almost seven miles deep. 

What awaits our future discovery in the remaining 2.2 miles?   Oceanlab may be able to tell us, because their equipment is reportedly capable of withstanding even that depth.

The expedition in the Japan Trench that set out on September 24 and returned on October 6 was jointly funded by the National Environmental Research Council in the U.K. and the Nippon Foundation of Japan.