Coral Bleaching Hot Spots
This map uses sea surface temperatures
to forecast the bleaching of coral reefs. It is updated twice
weeklyon Tuesdays and Saturdays. On the site where this
map is featured, you can click on any area of the map to see
a close-up view of that area.
Coral reefs are built by colonies of coral polyps, tiny animals
that live in a symbiotic relationship with algae. Under environmental
stress, coral polyps may expel their algae and lose their
color, a process known as coral bleaching. Coral bleaching
may lead to the death of the coral polypsand the reef
itselfand degradation of the ecosystem that the reef
Coral bleaching has increased over
the last two decades. Most of the major bleaching events of
the 1980s and 1990s have been linked to elevated water temperatures.
However, warmer water alone may not cause bleaching events.
Other other factorssuch as low winds and very sunny
daysmay amplify the thermal stress. A variety of other
environmental stressessuch as disease, excess shade,
increased levels of ultraviolet radiation, sedimentation,
pollution, and salinity changesmay also play a role.
In an effort to determine all the factors associated with
coral bleaching, NOAAs Coral Reef Team asks coral reef
scientists, divers, and others to report
coral bleaching and the conditions under which