Visitors to Monkey Reef off Great Keppel Island may see patches of bleached or seemingly dead corals. After a run of days with light winds and water temperatures peaking during the mid afternoons above 28 degrees C in the last 3 weeks, The bleaching sensitive branching corals on the shallow reef flat have started to show signs of heat and light stress stress and about 10% have died. Some bleaching and mortality on these shallow reef flats during the summer is normal. This can be relieved by strong winds which whip up waves and turbidity and prevent light from penetrating the water surface or by cloudy days or rainfall. Remember, at least in the Keppels, corals can regrow over existing dead tissue within a year.

1. Diaz-Pulido, G., L.J. McCook, S. Dove, R. Berkelmans, G. Roff, D.I. Kline, S. Weeks, R.D. Evans, D.H. Williamson, and O. Hoegh-Guldberg, Doom and boom on a resilient reef: Climate change, algal overgrowth and coral recovery. PLoS ONE, 2009. 4 (4): p. e5239.

Photos of Monkey reef courtesy Max Allen Jnr Freedom Fastcats Rosslyn Bay.

Square Rocks Weather Station water temperature data courtesy AIMS, Townsville.