This report considers how to mitigate damage caused by the growing exploitation of the planet's high seas, where marine life drives the ocean's 'biological pump'. It tests the feasibility of protecting 30% of the world's oceans through the creation of ocean sanctuaries.

This document is part of the status report series of the Global Coral Reef Monitoring Network (GCRMN) founded in 1995 as part of the International Coral Reef Initiative (ICRI) to document the ecological conditions of coral reefs, to strengthen monitoring efforts, and to link existing organisations and people working with coral reefs around the world.

The update was produced in response to World Heritage Committee Decision 41 COM7 (Krakow/UNESCO, 2017) to make available the most current knowledge regarding the impacts of climate change on World Heritage properties.

Like reefs all over the world, the Great Barrier Reef is under pressure. A big challenge demands a big response and, during the International Year of the Reef 2018, the Australian government is investing an additional half a billion dollars in its health and resilience.

This analysis showed that World Heritage properties containing coral reefs have been increasingly exposed to heat stress during recent years. Nearly half (13) of the 29 World Heritage Listed reef properties were exposed to levels of heat stress that cause coral bleaching, on average, more than twice per decade during the 1985- 2013 period.