Coral reefs
Sometimes called “rain forests of the sea,” coral reefs are
spectacular marine ecosystems that thrive in warm, clear,
shallow waters. Ecotourists love to visit the reefs to see
the colorful and amazing variety of animals that live
and hunt here.
RICH PICKINGS
Ocean predators such as
dolphins (left) and sharks
(right) lurk in coral reefs.
They feed on the small
creatures who live there.■ The main reef-forming
organisms are known as hard or
stony corals. Each one, called a
coral polyp (right), secretes
limestone from its gut cavity,
and this builds up on the rock
underneath. Some corals exist
as single, large polyps, but most
live in large colonies.THREATS TO CORAL
The reef is damaged by anchors
scraping its surface and
explosives thrown into the water
to kill fish. Coastal developments
release harmful sediment into the
water, and stress, such as higher
temperature, can cause coral to
expel the algae in their body, so
they turn white.■ Corals are actually simple animals with
tiny plantlike cells living inside them.
■ The Great Barrier Reef, off northeastern
Australia, is about 1,430 miles (2,300 km)
long.
■ Excess CO 2 in the atmosphere is making
the ocean more acidic, which could
damage coral.
■ Fossil reefs have been discovered dating
from more than 500 million years ago.FAST FACTS
TAKE A LOOK
ENVIRONMENTAND ECOLOGY
(c) 2012 Dorling Kindersley. All Rights Reserved.(c) 2012 Dorling Kindersley. All Rights Reserved.