Coral reefs are one of the most spectacular ecosystems on Earth.
They are being threatened by human actions, including global warming.
When corals are stressed, particularly by higher temperatures,
they can expel the algae which they get food from, turning white.
Corals can recover if the stresses are removed, but they can also die.
The conditions which lead to bleaching, and which allow for recovery,
are still not fully understood. Observations of whether or not corals bleach
and recover can help us better understand and protect them.
You can help by providing these observations!