Bleaching coral is under a very stressed state, and so it is not surprising that its resistance to various diseases is lower than in a normal, healthy state. So bleaching and pathogens attack with a double-whammy that can be fatal.
Mass bleaching of coral reefs has become a critical problem affecting the health of one of the most diverse coastal ecosystems in the oceans. Although already provides critical, timely information to coral reef managers and scientists based on near real-time satellite monitoring of thermal stress conducive to coral bleaching, an outlook of thermal stress during future months would be very useful for strategic planning and management. An experimental seasonal coral bleaching thermal stress outlook product has been developed by NOAA to provide such an outlook ranging from one week to four months (season) in advance. NOAA CRW and the of the NOAA Earth System Research Laboratory (ESRL) have teamed up in this effort.
Credit: Khaled bin Sultan Living Oceans Foundation
Extensive aerial surveys are being complemented by in-water surveys by coral biologists. By getting in the water, scientists are better able to ascertain the severity of the bleaching, establish which types of corals have been worst affected, and make predictions about what proportion of the bleached corals are likely to die. The trade-off is that they cannot cover as many locations as an aerial survey.
Coral die-offs—caused by a process known as bleaching—tend to look as bland and lifeless, in contrast to the vibrant rainbow colors of thriving coral. Bleached coral reefs usually appear as an endless stretch of white coral and eventually turn to dead brown coral. But in New Caledonia Vevers found something different.