Watch: First sign of coral bleaching found in Sydney!

World's largest marine heritage is under threat. For the first time ever, coral population in Sydney Harbour is showing signs of bleaching due to warm waters, according to the scientists.

The researchers of the two Australian universities, University of Technology (UTS) and Macquarie University made this shocking revealation in which they discovered the first ever incident of 'paled coral colonies during routine monitoring at a number of locations in Sydney Harbour'

The coral colonies thrives in cold water but the El Nino season of 2015-16 raised the temperature of the East Australian Currents.

The researchers claimed that around 45% of harbour's hard corals has been devastated by these warm waters.

Coral bleaching usually occurs when the temperature of sea water rises abnormally. Several factors are responsible for such warm waters like climate change, global warming, El Nino etc.

The video below shows how slowly and steadily we are losing the most diverse underwater ecosystem.