STRANGE BUT TRUE- ANNUAL MANUAL- Porpoise-ful: How dolphins are just like us


DRAWING BY DEBORAH DERR McCLINTOCK

Q. What were some bottlenose dolphins spotted doing recently off the coast of Australia, moving them into our own celebrated category right along with chimpanzees, sea otters, and woodpecker finches? –J. Cousteau

A. The dolphins were sporting cone-shaped sea sponges on their beaks, the first clear case of tool use by wild dolphins or whales, says Bruce Bower in Science News. 

These "brainiacs of the marine world" will dive to the bottom of deep channels and poke their sponge-enhanced beaks into the sandy ocean floor to flush out small fish, devoting some 17 percent of their time "fishing"– more tool-time than any non-human animal, says biologist Janet Mann of Georgetown University. In that sense, bottlenose dolphins are also "workaholics of the seas."

Chimpanzees, it turns out, spend a small amount of time using tools, sea otters and killer whales appear to employ tool-help while foraging, and one group of woodpecker finches spends an estimated 10 percent of its time using twigs and cactus spines to pry insects and spiders out of tree holes.

Q. They can measure three football fields long and 14 stories high, move at 25-30 mph, generate 100,000 horsepower yet deftly turn on a dime while spinning 360 degrees or moseying sideways. Perhaps you've luxuriated in one of these "nimble skyscrapers at sea," where fully one-third of the massive power generated goes into catering to the desires of its 18,000+ inhabitants. Inhabitants of what? –A. Zumwalt

A. Those magnificently bedecked cruise ships such as the Oosterdam, owned by Holland America Line, boasting myriad mechanical systems spread across the lower decks and rarely seen by passengers, says Mark Fischetti in Scientific American magazine. A single engine could fill a suburban living room. Many ships incorporate a propulsion system, or Azipod, on a hefty swivel to allow movement in any direction. 

The price of all this power and pampering (400 room stewards and 400 waitstaff) comes to about 90 gallons of heavy fuel oil consumed per mile at modest speed and 140,000 gallons of seawater desalinated daily to provide fresh water for the passengers and others. 

As soon as vacation-goers step on board, they enter into the legal system of the ship owner's home country.

"For example, the Oosterdam sails under the Dutch flag, so all people on board are subject to Dutch law," Fischetti says.

Q. You never want to try this, but how might a certain mismanaged water sport get your body's blood bubbling up and "boiling over" like an exploding champagne bottle shooting out its cork? –C. Nemo

A. Donned in scuba-diving gear, descend deep into the ocean and then re-surface too fast, causing dissolved and compressed gases in your blood to come rapidly out of solution, a condition called "the bends," says marine scientist Ellen Prager in Chasing Science at Sea. 

At the surface, there is one atmosphere of pressure (atm) from the weight of the overlying air, then another atm for every 34 feet (10 meters) of water down, soon becoming an enormous pressure. As a diver goes deeper, this increased pressure causes the blood to absorb more gas, which must be slowly purged before returning to the surface. Now consider a bottle of champagne, its carbonation staying dissolved until you pop the cork, causing excess gas to expand rapidly and bubbles to shoot the cork across the room. "A diver's body at depth can be likened to a champagne bottle that we don't want to uncork," says Prager 

Once while she was living in the Aquarius underwater habitat, Prager says, a doctor made a "house call" for a routine checkup, took a sample of her blood and brought it directly to the surface. The blood bubbled so violently it shot the stopper out of the vial– "a powerful and sobering illustration of what would happen if any of us, once saturated, made a beeline to the surface without going through decompression," she reports.

~

Send Strange questions to brothers Bill and Rich at strangetrue@cs.com.

#