How are coral reefs becoming endangered?

Coral reefs all over the earth are endangered.  Coral mining, run-off from agriculture and urban centers, overfishing, blast fishing, and disease is killing coral at alarming rates.  As a result, corals are under heavy amounts of stress, which sometimes results in coral bleaching.  Many of the world’s coral reefs saw a massive dieoff due to coral bleaching in 1998 and continue to suffer in some areas today.