its terrible to see the reef getting slugged so often with hotter water. I don't see how it can be stopped with efforts to replace our "warm water" coals replaced with hot water corals so restricted to small localities. but the spawning should result in some slow spread of the hot water varieties.
now that the Aus coastal current is done to Sydney we're likely to see the development of warm water and hot water corals down the NSW coast. - until the water gets too hot for NSW and the spread gets thinner.
what we'll have in 50 years is what I'm concerned about. the current off Syd is 27o. likely to reach 35o if it keeps going at this rate. hotter than the average summer bath. people won't go to the beach when the water is too hot. and this will further raise the atmospheric temperature and humidity. by then it will be classed as runaway warming.
