Come Out, Come Out Wherever You Are

Last Friday's,  August 5th,  edition of "Science Friday" highlighted cephalopods - squids, cuttlefish and octopus.

Divers know that octopus can sometimes be elusive critters especially when a new diver wants to see one but this must see video might surprise you on just how well they can blend in with their surroundings. Not only do cephalopods have the ability to change colors and patterns but they can change texture as well making them truly masters of camouflage.

Dr. Roger Hanlon, marine biologist with Woods Hole , has captured some amazing videos over the years documenting this behavior.

So, that next dive when you get the feeling your being watched - it's probably just a cephalopod keeping an eye on you.

The video is from Science Friday's website with music credit to DjCode, video courtesy of Roger Hanlon and produced by Flora Lichtman

"Two Brothers" Discovered Off Hawaiian Coast

The wreck of the whaling ship, Two Brothers, was discovered by maritime archaeologists 600 miles northwest of Honolulu. The ship, captained by George Pollard, Jr., went down on the night of February 11, 1823 after striking a reef in about ten feet of water in a poorly mapped area known as the French Frigate Shoals. Nearly two centuries later the warm ocean waters of the Pacific has reclaimed most of the wooden ship but archaeologists were able to recover several artifacts including harpoons and some of the cooking pots used by the whalers to turn whale blubber into oil.

Dr. Kelly Gleason with a ginger jar from the shipwreck Two Brothers.

Photo by Greg McFall/NOAA

Unfortunately this was not the first ship Captain Pollard had lost at sea. His first command was the whaler, Essex, which was rammed and capsized by a sperm whale. The incident inspired Herman Melville to pen the great American novel, Moby-Dick. After the sinking of the Essex Pollard and his crew were adrift at sea for three months with no food or water, resorting to cannibalism to survive, before finally being rescued.

The loss of the Two Brothers was much less eventful as they were sailing in the company of another whaling ship which had taken shelter nearby. All hands were recovered the next morning with no loss of life.

Dr. Kelly Gleason, the maritime archaeologist that led the discovery of the Two Brothers, originally found the ship's anchor in 2008 during a survey of the French Frigate Shoals but it wasn't until more artifacts were uncovered over the course of the next two years that confirmed the last resting place of the whaler.  

Officials from the Papahanaumokuakea Marine National Monument announced the findings today, exactly 188 years to the date of the sinking of the Two Brothers. Gleason says the artifacts are scheduled to go on display at the marine monument's Discovery Center in Hilo.

In depth article can be found here and video interview with Dr. Gleason here.

I'll Have A Fin & Tonic Please

Tonic immobility is a natural catatonic state that some animals enter into when they perceive a threat. By becoming immobile they hope to avoid attracting attention from a possible predator. Sharks when inverted onto their backs enter this state but it is unknown why. It is possible it disturbs their balance or some electrical field within their anatomy. Orcas have been know to use this to their advantage. Witnesses have seen an Orca ram a Great White Shark dazing it before maneuvering the shark onto its back inducing tonic immobility and rendering it helpless to the attack. Orcas have also been filmed off the coast of New Zealand feeding on stingrays using tonic immobility.

Divers experienced with sharks have learned that rubbing the nose of a shark is evidently a pleasurable sensation that elicits a calming state in the animal. While this should not be confused with the catatonic state of tonic immobility it does allow the diver to create a trance like state in the shark. Once sufficiently relaxed the diver can then position the animal at any attitude, from standing the shark on its nose to fully inverting it on its back to induce tonic immobility.    

Life's Abyss and Then You Dive

In 1989 Director James Cameron's sci-fi film "The Abyss" featured the use of liquid oxygen which permitted a diver to reach extreme depths wearing a diving suit. Cameron did not invent this concept for the movie as the breathing of perfluorocarbons (PFCs) had been theorized, studied and eventually even tested years before. Today some of the leading hospitals are using PFCs for treatment of premature babies with remarkable success. PFCs studies have also been carried out by the Navy in the treatment of decompression sickness (DCS) on swine.

Now Arnold Lande, a retired American heart and lung surgeon, has patented a scuba suit that would allow a human to breathe "liquid air". The liquid would be contained in a closed helmet, just like the one Ed Harris' character used in the movie. The PFCs would fill not only the lungs but all the air cavities - ear, nose and sinuses. CO2 that builds up would be expelled through a mechanical gill attached to the femoral vein in the leg. The suit would allow divers to descend to depths far greater than possible now and not worry about DCS. 

The practical use of PFCs, whether for the treatment of DCS or to extend depth ranges, is still several years away. But it does appear that sometime in the future divers may be taking specialty courses utilizing the science of "liquid air".  

Link to the full article in The Independent.