Whale sharks to be tagged to save species
Technology will uncover the mating secrets of these enigmatic giants
It is the largest fish in the ocean with some individuals reaching sizes
of up to 65ft (18m) long and weighing more than 30 tonnes, but whale
sharks remain one of the enigmas of the deep.
There are fears that the gentle giant, whose flesh is prized in
countries such as China, India and the Philippines, is being slowly
driven towards extinction. And so little is known about them that there
is huge uncertainty about how their decline can be arrested.
Scientists and conservationists hope to safeguard the giant
creatures' future by electronically tagging them to uncover their
secrets. The project is being supported by the Galapagos Conservation
Trust.
Spokesman Peter Haskell said: "We are starting to build a picture of
the whale shark's global migration."
Divers from the Galapagos Whale Shark Trust plan to tag both males
and females off the coast of Peru to trace where they go and what they
do. One of their main hopes is that it will reveal where in the ocean
the species courts and mates, a key piece of information in the fight to
understand and protect it.
"We don't know where they mate, we don't know where they give birth
and we don't know where they spend the first couple of years of their
lives," said Dr Alex Hearn of the Galapagos Whale Shark Trust.
Added urgency has been injected into this research by the rate at
which whale sharks are being caught and eaten. While most deliberate
fishing for them has been halted, they are still taken in large numbers
as a bycatch.
It is also suspected that there is illegal fishing targeting them. In
China, where the bulk of whale sharks are processed for the food
industry, a single factory in Puqi has the capacity to process up to 600
carcasses each year.
Each carcass can be worth as much as £19,000 and the best fins, some
desired as ornaments while others go into making soup, can sell for
several thousand pounds each.
At least 1,000 whale sharks are processed in China each year and
quite possibly many more.It was recently discovered that the adult whale
sharks in the Galapagos are all females, feeding for a couple of days
before heading out into the openocean.
Most have distended underbellies which leads researchers to suspect
that they are pregnant.Dr Hearn and other researchers suspect females
give birth far out in the ocean, probably in deep water and most likely
one at a time.
They speculate that the young live close to the seabed in deep-water
areas for two years before migrating.
- The Independent
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