Researchers Expect The Most Critical Coral Bleaching In 20 Years

More and more corals are breaking up with their colorful life partners, small protozoa, in what seems to be one of the most severe bleaching episodes in recent history. Air temperature worldwide has reached its peak level. Global warming is a fact and not many dare to deny it. Under these circumstances it is not difficult to presume that the oceans’ temperature is also increasing. And one of the effects of the constant warming of our planet is one the most critical coral bleaching chapter in 20 years, according to scientists.

The bleaching describes a phenomenon when coral casts out the a protozoa that inhabits their tissues, either on their outer surface or inside. These protozoa are similar to algae and are called zooxanthellae.

The health of the coral is dependent on these microorganisms as they give it its color and help it with the photosynthesis process. Though the ejection of the zooxanthellae does not lead to the coral’s death, it makes it significantly more defenseless against other natural factors and more likely to get diseases.

Since coral reefs are the of biological spine for numerous marine creatures acting like food and haven for the smaller fish and other aquatic forms of life, their wellbeing is imperative to maintain the ocean’s diversity.  Scientists predict that as waters heat up and gather more acid, the coral bleaching occurrences are bound to happen at a larger scale and with increased frequency.

Normally, significant bleaching episodes only take place during El Niño, which is an intermittent warming stage in the Pacific that happens every two to seven years.  It usually lasts up to a year and sets in motion a series of chain responses consisting in barometrical and climatological episodes.

However, now the ocean temperatures are close to reaching an all-time peak and, as a result, it is conceivable that these heating episodes will trigger a domino effect of coral bleaching phenomena across the global waters.

So far, researchers observed coral bleaching in the ocean regions of Florida, Hawaii, Guam, Marianas Islands, Kiribati and Tuvalu. But they are expecting to spot them in the following period all through the Pacific Islands and along the banks of Australia.

The last huge bleaching event took place in 1998 and was caused by an especially big El Niño in conjunction with global warming.  At that time, coral colonies all around the globe expelled their zooxanthellae organisms.  About 15% of the world coral died.  This year’s bleaching is believed to continue expanding in the next few months.

Ove Hoegh-Guldberg, a marine biology researcher at the University of Queensland declared that numerous coral reef researchers are anticipating something comparable to what happened in  1997-98 to unfold in the following six to 12 months.

Corals normally overcome the bleaching episodes by proposing  zooxanthellae to move back in with them. At the same time they need a period to mend after these episodes, and with waters warming and increasing bleaching events that process becomes troublesome.

Image Source: Tree Hugger