1998 Mass Bleaching Event
Photo. Dr John Hooper, QM.
Before 1998 the Great Barrier Reef hadn't experienced a mass bleaching event quite as severe as this year, and since then mass bleaching has become a issue that affects tropical reefs all around the world. This particular event in 1998 occurred due to the ENSO that happened the summer before in 1997 which was the hottest summer on record in the Great Barrier Reef. The seas started warming in the January of 1998 and got increasingly hotter over February and March. It is believed that there were many factors that added to the intensity of the event, high sea temperature, freshwater dilution due to flooding and high light intensity. In some areas the mortality on the reef reached 80% but a survey taken the next year showed that of the 48 reefs sampled only a small percentage had lost area cover (cRc). A survey done by the GBRMPA showed 42% of reefs obtained some sort of bleaching and 18% of those experienced strong bleaching.