Scientists developed a model to identify corals most at risk of bleaching

Waters off Australia's northeast coast face more severe marine heat waves

Australian scientists have developed a model that will help researchers identify soft corals that are most vulnerable to bleaching from marine heat waves. Coral bleaching has affected most reefs around the world. Australia's Great Barrier Reef was hit by four mass bleaching events in the past seven years. Marine biologist Rosie Steinberg said her research showed one type of soft coral was healthier during a heat wave and produced more algal cells than when the temperatures were normal. Hard corals are the primary reef-building corals, while soft corals, which resemble underwater plants or trees, lack a hard outer skeleton. Soft corals are under-researched as they do not form reefs, though they are present in reef ecosystems.

Frozen samples of soft coral are ground to create a puree, which is put through a centrifuge that separates algal cells from coral protein. Researchers will then look at the quantity of protein, algal cells, and chlorophyll, which are all indicators of coral health. Soft corals take more time to bleach than hard corals, but it would be catastrophic when they become affected. Waters off Australia's northeast coast face more severe marine heat waves, environmental group Climate Council said this year, after sea surface temperatures there raised to around 2-4 degrees Celsius above average.