Box 1.7 Damage to the Great Barrier Reef, the world’s largest coral reef system
The most recent ocean tragedy is the worst coral die-off ever recorded in Australia’s Great Barrier Reef (GBR). Driven by climate change, in early 2014 warming seawater temperatures triggered a global bleaching event. By 2016, global bleaching was affecting and killing coral reefs all over the Pacific Ocean. In that year the northern part of the GBR lost two-thirds of its coral over a stretch of 700 kilometres (Hughes, Schaffelke and Kerry 2016; Innis 2016). This is the single largest known coral die- off in bleaching history. Another episode of bleaching in the middle part of the GBR occurred the following year. In June 2017 seawater temperatures started to cool and return to normal levels.
This bleaching event lasted almost three years, during which almost 29 per cent of the GBR coral died. There were also wider impacts on reef ecosystems. For example, many reef animals lost their homes. There was also significant economic loss due to reduced fishing, recreation and tourism.
Figure 1.8 Coral at Lizard Island on the Great Barrier Reef turned completely white (coral bleaching) and died in March 2016; in May 2016 it was covered with algae
