If you’ve ever had the privilege of seeing glow-in-the-dark coral you’ll know that it’s one of nature’s most beautiful creations.
Usually found in shallow waters the coral’s impressive ability is actually a form of sunblock that helps protect it from the Sun’s harmful rays.
What has also puzzled researchers though is why deep-sea coral glows as well, for starters it’s too far from the Sun to need protection.
Well now researchers at the University of Southampton believe they’ve unraveled this mystery.
While shallow coral use it to protect themselves, deep sea coral use it for the complete opposite.
Down at depths of 160m or more the only light that can penetrate far enough is blue light.
It appears as though the corals are able to create a special florescent protein that absorbs this blue light and then converts it into orange/red light which is then easily absorbed by symbiotic microscopic algae that provide a coral with 90% of its energy needs.
This friendship between the corals and the algae (known as zooxanthellae) is mutually beneficial. The tiny algae gets shelter, carbon dioxide and nutrients while the coral gets the photosynthetic products needed for energy.
Prof. Jörg Wiedenmann, head of the Coral Reef Laboratory at the University of Southampton warns that this discovery has worrying consequences for the survivability of coral reefs in general.
“Deep water habitats are discussed as potential refuges for corals from the increasingly degraded shallow water reefs” explains Prof. Wiedenmann. “Our work shows that the ‘deep blue sea’ may not be the welcoming sanctuary our endangered coral reefs can retreat to without consequence.”
Understanding how corals work doesn’t just aid our understanding of the ecosystem, it can also have a major impact on human health as well.
Scientists are already harnessing this fluorescent proteins in the battle against cancer by using them as powerful light sources making cells easier to see under a microscope.