New Scientist - July 27, 2019

(やまだぃちぅ) #1
27 July 2019 | New Scientist | 29

A real mouthful


Photographer Michael Aw
Agency Image Quest Marine

“FISH are friends, not food,” goes
the famous line in the film Finding
Nemo. But these whale sharks
clearly didn’t get the memo. The
filter feeders strain small fish and
plankton from the water using
their large mouths, which can
reach 1.5 metres wide in the
biggest individuals.
Whale sharks, Rhincodon typus,
are the biggest fish on Earth,
reaching up to 20 metres long and
weighing up to 20 tonnes. Despite
their size, the slow-moving giants
aren’t dangerous to humans –
juveniles have been known to
play with divers. But humans
are a threat to them, with the
species considered endangered
as numbers decline from fishing,
accidental capture alongside other
fish, and collisions with vessels.
This photograph was taken in
Cenderawasih Bay, off the coast of
the Indonesian provinces of Papua
and West Papua. Whale sharks
are found year-round here, often
emerging at the water’s surface
and swimming close to bagan,
mobile fishing platforms with
attached fish traps or nets. The
sharks have learned to feed on
fish through nets, and also receive
handouts from locals.
Around the world, whale sharks
are found in tropical waters. They
tend to cluster at various coastal
areas, drawn by seasonal increases
in prey, including zooplankton
blooms and fish spawning. While
they spend the majority of their
time in the top 200 metres of the
ocean, the sharks regularly dive
to more than 500 metres, with
some dives to depths of more
than 1 kilometre recorded. ❚

Donna Lu

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