IUCN ASSESSMENT PUTS 96 PER CENT OF SHALLOW REEFS AT RISK

The International Union for Conservation of Nature (IUCN) says 96 per cent of shallow-water coral reef ecosystems face an extremely high risk of collapse by 2075. Its global assessment classifies every reef ecosystem it evaluated as critically endangered. Marcos Valderrábano of the IUCN said researchers lacked enough data to assess the remaining 4 per cent, which he considered similarly vulnerable. The assessment identifies warming oceans and marine heatwaves as major threats. The IUCN presented the findings at a United Nations biodiversity conference; accounts place the conference in either Armenia or Albania.

The assessment includes the Great Barrier Reef in Australia, the Coral Triangle in the Western Pacific and Southeast Asia, the Mesoamerican Barrier Reef System and Red Sea reefs. The IUCN classifies all four as critically endangered. According to the assessment, shallow reefs cover about 1 per cent of the ocean and support a quarter of marine species. Hard corals can give way to algae, rubble and sponges when a reef collapses. Reefs also provide fishing and tourism income and help protect coasts from erosion and storms.

The IUCN estimates that up to one billion people rely on coral reefs for fishing, income or coastal protection. Valderrábano said countries could protect reefs by reducing fishing quotas and pollution. Mishal Gudka, the assessment’s scientific lead, said: “The risk of coral reef collapse is escalating, but this must be a wake-up call rather than a cause for despair.” Gudka said surviving pockets of coral could remain after bleaching events. James Guest of Newcastle University said small, dispersed coral populations could struggle to reproduce if their eggs and sperm could no longer meet.