WATER - Coral reefs

Pacific atoll

Atoll in the Pacific Ocean.
IKONOS (23/09/01).
Source: GeoEye.

Satellites monitor health of coral reefs

This IKONOS 4-meter resolution image shows part of an atoll in the Pacific Ocean. Atolls are coral islands encircling a lagoon.

Coral reefs are some of the most diverse and valuable ecosystems on Earth. They are home to myriad fish and invertebrate reef species.

However, reefs worldwide are increasingly under threat from coral bleaching. Scientists use satellite data to survey and map coral decline all over the world.

Question: How can satellites help to study and protect coral reefs ?