Coral Bleaching

Coral Bleaching threatens much of our fragile coral reefs around the world.   In 1998, sea-temperature warming caused extensive coral bleaching in the Maldives.  As a result, almost two thirds of coral reefs died.

Again, in May of 2016, the coral reefs of the Maldives experienced a severe bleaching incident. Furthermore, the surface water temperatures reached an all-time high at 31 degrees Celsius in May 2016. Consequently, over 95% of coral reef around the islands died.

Scientist Azeez Hakim stated:

“before 1998, we never thought that this reef would die. We had always taken for granted that these animals would be there, that this reef would be there forever. El Niño gave us a wake-up call that these things are not going to be there forever. “

In Australia, back-to-back bleaching events in 2016 and 2017 devastated a

1,500 km stretch of the famous barrier reef. While, before 2016 there had only been two bleaching events along the Great Barrier Reef in the past two decades.

We have seen a number of mass bleaching events in 1998, 2002, 2006, 2016 and in 2017 in various parts of the globe.  Furthermore, with these bleaching events we are seeing not only an increase in events but also an increase in the number of regions impacted per event.

Coral Bleaching – Why should we be concerned?

Coral reefs cover less than one tenth of one percent of the earth’s oceans.  Yet these same reefs contain one quarter of known marine fish species (Smithsonian Institute).

Reefs are formed by Corals “… animals that live in symbiosis with algae, a plant,”.  This is according to Jessica Bellworthy a PhD student at Professor Interuniversity Institute for Marine Sciences. The university’s study of Red Sea corals seeks to understand their ability to resist extreme temperatures.

Corals and algae “provide services for each other.”  Algae provide “up to 90 percent of the coral animal’s food” through photosynthesis, said Bellworthy.  “When ocean temperatures get too hot, this symbiosis, this relationship, breaks down,” she said.

Yet in the Red Sea, where I have been diving many times, ocean temperatures can be much higher.

The Red Sea routinely experiences temperatures higher than the Maldives or in Australia.  So, could the Red Sea corals offer an opportunity to introduce “bleach resistant” coral into other threatened areas?

Dr. Fine’s research regarding Red Sea corals may provide potential avenues and approaches to protect our coral reefs in the future.

Scripts Institute of Oceanography

Scripts Institute conducted a study of coral bleaching in the central Red Sea in the summer of 2010.  During this event the region experienced up to 10-11 degree increases in temperature for many weeks. Correspondingly, the study found that shallow reefs and inshore reefs had a higher prevalence of bleaching. Furthermore, while Red Sea reefs are subject to increasing temperature pressures, the study showed that these reefs have a much higher temperature change tolerance.  Therefore, the implications are quite clear.   Corals that have lived and thrived in higher temperature environments are better suited to survive higher temperature seas in other areas.  Could these more temperature tolerant corals provide the basis for saving coral reefs in other areas?

Opportunities for Change

Consequently, saving our coral reef system is critical to maintaining food stock, industries and related jobs in many countries around the world.  However, introducing non-native coral species into a specific environment poses a number or questions and risks.  Should we introduce corals that are already acclimated to higher temperatures to other environments? What would be the impacts of introducing non-native species? Would this help eliminate bleaching events or reduce their impacts?

The answer to these questions any other related questions could determine our ongoing ability to feed ourselves and our children in the future.