Page 28 - ARUBA TODAY

A28 SCIENCE
Thursday 1 March 2018

Cracking the mysteries of the elusive, majestic whale shark

By MARIA CHENG Yet another theory sug-
Associated Press gests whale sharks may
GALAPAGOS ISLANDS, Ec- be giving birth closer to
uador (AP) — It’s the big- Peru — after two newborn
gest shark — and the big- whale sharks were found in
gest fish — in the sea, often fisheries there recently.
found roaming in warm RESULTS
waters around the globe Because of the difficulty
with its huge mouth agape of conducting a medical
in search of dinner. exam on a free-swimming
Yet despite its hulking ap- whale shark, researchers
pearance, the whale shark only obtained two blood
has only tiny, almost use- samples, which haven’t
less teeth and is sometimes yet been tested. The ul-
so docile that entire boat- trasound exams were in-
loads of people can swim conclusive and Green
alongside the enigmatic, said more powerful ma-
spotted beast. It’s also one chines are needed. Most
of the least understood ani- ultrasound machines for
mals in the oceans. animals are intended for
In an attempt to solve abdominal walls that are
some of the most enduring 1 to 2 inches thick — but a
mysteries, a group of sci- whale shark’s abdominal
entists spent several weeks wall is about 8 inches.
diving with whale sharks “When we first started
in the Galapagos Islands In this 2017 photo provided by Simon Pierce, Alexandra Watts takes a tissue sample from a whale studying these large ani-
last summer and fall. They shark in the Galapagos Islands area of Ecuador. mals, nobody knew how to
tried some never-before- Associated Press go about it,” Green said.
used techniques on the ies are covered in dots that their movements. Others visiting divers to figure out “Now that we have better
species in the wild: taking act as camouflage under- are trying to answer ques- what the whale sharks are technology and more ex-
blood samples and doing water. tions about their life and up to. So far, none of the perience, we will hopefully
ultrasound exams, all while After years of being over- reproductive cycles. Only sharks spotted in the Gala- be able to answer some of
swimming furiously beside hunted by fishermen, whale one pregnant whale shark pagos has been seen any- the fundamental questions
them underwater. sharks are endangered has ever been found: In where else. soon.”
Here’s what’s known about and at risk of extinction. 1995, a dead whale shark Besides blood and ultra-
these massive marine ani- HANGOUT SPOTS was found off the coast of GALAPAGOS DIVES sound tests, scientists suc-
mals and what scientists Whale sharks prefer warm Taiwan with 300 embryos The Galapagos Islands are cessfully tagged seven
are still trying to find out: waters and are often inside, all at different stages among the few places sharks. While not a large
WHALE OR SHARK? found feeding at locations of development. in the world where pre- number, it’s important
While they are compara- around the world including “The million-dollar ques- sumably pregnant whale since so few whale sharks
ble in size to whales, whale Australia, the Philippines, tions are where are they sharks are regularly seen. are tracked. The pressure
sharks are sharks. They typi- Mexico and even in the oil mating, hunting and where More than 99 percent of of deep water can cause
cally grow to be bigger fields off the coast of Qatar. do their young live?” said the sharks identified in the tags to drop off if the sharks
than a double-decker bus: Hundreds of whale sharks Jonathan Green, director volcanic archipelago are dive below 2,000 meters
between 6 to 16 meters (20 — mostly young males — of the Galapagos Whale female and many have a (6,561 feet), which the
to 52 feet) and more than congregate in these areas Shark Project . swollen abdomen that sug- animals often do if they’re
20 tons. But as filter feeders, at certain times of the year An international database gests they’re expecting. traveling long distances
the enormous whale sharks to scoop up fish eggs; it’s was launched to identify Some scientists believe or possibly giving birth. But
are dangerous only to the unknown where adult fe- as many whale sharks as pregnant whale sharks any migratory data the sci-
plankton, fish eggs and tiny males are feeding then. possible through their dis- are cruising through the entists collect when sharks
fish they chomp on. The vastness of the ocean tinctive dot pattern; each Galapagos, perhaps to ex- stay at shallower depths
The gentle giants aren’t usually makes the shy ani- shark has a unique configu- treme depths close to the can help build a picture of
particularly fast when com- mals hard to find — Jacques ration of dots that act like a northern-most island or to the sharks’ life cycle.
pared to other sharks, but Cousteau only ever saw fingerprint. More than 8,000 the open ocean near the Green and colleagues are
a simple wave of their tail two in his decades of sea sharks have been logged equator to give birth. Either planning further expedi-
propels them through the exploration. so far. Because scientists place would probably en- tions to the Galapagos
water faster than any hu- TRACKING WHALE SHARKS can only afford to spend sure the safety of their off- later this year to continue
man could ever swim. They Marine biologists have a few weeks in the Gala- spring from predators until their research, including
have broad, flat heads and been tagging whale sharks pagos each year, they de- they’re big enough to sur- more blood samples and
their entire dark-blue bod- in recent years to track pend on photos taken by vive on their own. satellite tagging.
“When you have so few
data points, every single
shark is important,” said
Robert Hueter, director of
the Center for Shark Re-
search at Mote Marine
Laboratory in Florida, who
was not part of the Gala-
pagos research. “These
aren’t like goldfish where
you can get sample sizes
of hundreds at a time.”q