Scientists find coral reefs emit dazzling colours as 'sunscreen' - Metro.co.uk

Corals during a colourful bleaching event in the Philippines in 2010 (Credits: PA)

Some corals emit a ‘sunscreen’ in the form of a dazzling colourful display to protect them from rising sea temperatures, according to new research.

Scientists at the University of Southampton believe that the corals emit the bright neon colours in a fight for survival.

The team from the university’s coral reef laboratory explained in a report published in the journal Current Biology that many coral animals live in a fragile symbiosis with algae embedded in their cells.

A rise in water temperature of just 1C can cause this relationship to break down causing the algae to be lost leaving the coral’s limestone skeleton exposed through its transparent tissue leading to the fatal condition of coral bleaching.

But the study found that in mild or brief warming incidents, some coral produced a type of sunscreen which takes the form of the colourful display which encourages the algae to return in an ‘optical feedback loop’.

The University of Southampton's waterfront campus where researchers looked at how corals protect themselves against warming temperatures. (Credits: PA) — The University of Southampton’s waterfront campus where researchers looked at how corals protect themselves against warming temperatures. (Credits: PA)

Professor Jorg Wiedenmann explained: ‘Our research shows colourful bleaching involves a self-regulating mechanism, a so-called optical feedback loop, which involves both partners of the symbiosis.

‘In healthy corals, much of the sunlight is taken up by the photosynthetic pigments of the algal symbionts.

‘When corals lose their symbionts, the excess light travels back and forth inside the animal tissue, reflected by the white coral skeleton.

‘This increased internal light level is very stressful for the symbionts and may delay or even prevent their return after conditions return to normal.

‘However, if the coral cells can still carry out at least some of their normal functions, despite the environmental stress that caused bleaching, the increased internal light levels will boost the production of colourful, photoprotective pigments.

‘The resulting sunscreen layer will subsequently promote the return of the symbionts.’

Staghorn corals during a colourful bleaching event in New Caledonia in 2016. (Credits: PA)

‘As the recovering algal population starts taking up the light for their photosynthesis again, the light levels inside the coral will drop and the coral cells will lower the production of the colourful pigments to their normal level.’

Dr Cecilia D’Angelo, lecturer of molecular coral biology at Southampton, added: ‘Bleaching is not always a death sentence for corals, the coral animal can still be alive.’

Staghorn corals during a colourful bleaching event off Lizard Island in 2010. (Credits: PA)

‘If the stress event is mild enough, corals can re-establish the symbiosis with their algal partner.

‘Unfortunately, recent episodes of global bleaching caused by unusually warm water have resulted in high coral mortality, leaving the world’s coral reefs struggling for survival.’

Let's block ads! (Why?)

"dazzling" - Google News
May 21, 2020 at 11:08PM
https://ift.tt/2zSQlaa

Scientists find coral reefs emit dazzling colours as 'sunscreen' - Metro.co.uk
"dazzling" - Google News
https://ift.tt/2SitLND
Shoes Man Tutorial
Pos News Update
Meme Update
Korean Entertainment News
Japan News Update

Bagikan Berita Ini

Search

Scientists find coral reefs emit dazzling colours as 'sunscreen' - Metro.co.uk

0 Response to "Scientists find coral reefs emit dazzling colours as 'sunscreen' - Metro.co.uk"

Post a Comment