By Amina Khan
A robotic ocean explorer has found the first Antarctic whale fall marine scientists have ever studied — and discovered nine new deep-sea species among the critters living off the enormous skeleton, according to British researchers.
The 35-foot southern Minke whale bones, described in the journal Deep-Sea Research II: Topical Studies in Oceanography, give researchers a rare glimpse into the rich ecosystem provided by these giant sea creatures once they die.
Whale falls — when the body of a deceased whale sinks to the bottom of the ocean — can become an oasis rich in resources for deep-sea life. That ecosystem develops in stages: First, swimmers such as sharks, hagfish and crustaceans will gnaw off the flesh. Next, other hungry critters will break down the remaining soft tissues. Then chemical-consuming microorganisms will break down the waste sulfide left by previous generations, a process that may take decades.
Researchers have gone to great lengths (and depths) to study whale falls, even sinking whale bones to the sea floor so that they can see what happens to them. But old, natural whale falls are most valuable because they allow scientists to glimpse processes that have been taking place and evolving over years, if not longer.
Even though the Antarctic is flush with the giant swimming mammals, researchers had never before chanced upon a carcass along the southern ocean sea floor. In fact, only six whale falls have ever been documented.
Running across one of these giant bone collections, then, takes a little bit of luck. The whale remains were spotted near the very end of an expedition, lying on the seabed between 4,737 and 4,747 feet beneath the surface. Many of the bones, particularly smaller ones, were missing. Based on the decay, the researchers estimated the whale fall could be anywhere from four to 64 years old.
After the researchers first glimpsed the whale’s vertebrae, they found nine new species among the many creatures living off of the animal’s remains, including a type of bone-boring zombie worm and an isopod crustacean that's similar to wood lice.
But how would such creatures survive over those times of whale-carcass scarcity? Before answering that question, the researchers may have to figure out if these are actually whale-specific feeders or simply other deep-sea critters taking advantage of the sudden riches.
"It was not clear which of the surrounding fauna were whale-fall specialists or 'background' deep-sea fauna using the whale-fall opportunistically as an additional food source," the authors wrote.