Anyone who’s scuba-dived along a coral reef knows how beautiful these colourful ecosystems are. But did you know they glow fluorescent under blue light? A group of researchers from the University of Southampton recently set out to discover why deep water corals glow, and in doing so, captured some absolutely beautiful imagery of these mysterious underwater plants.
Along with his team, Professor Jörg Wiedenmann, head of the Coral Reef Laboratory at the university, showcased their findings at the recent Royal Society Summer Science Exhibition. It’s known within the science community that corals in shallow waters glow because of fluorescent proteins that act as sunblock, protecting them from the sun’s intense rays.
However, Professor Wiedenmann and his team wanted to focus on coral that survives in water as deep as 165 metres, where little sunlight can penetrate. Working with researchers in Israel, they discovered that corals in deep water are fluorescent for the opposite reason to those in shallow pools – to absorb what little light there is, for the benefit of the photosynthetic micro-organisms that provide most of their energy needs.
The team established that corals survive in deep water by making a special type of fluorescent protein that captures blue light and re-emits it as orange-red light, hence these striking photographs. “This is an important step forward in understanding how the mysterious fluorescent pigments in corals work”, says Professor Wiedenmann. “Our findings help us to understand how the amazing diversity of colour structures the communities on coral reef.”
These fluorescent proteins also have important applications for human health. By glowing green, yellow and red under a blue light, they enable scientists to make important discoveries in cancer and HIV research, by lighting up living cells so they can be seen under a microscope. “Coral reef survival is dangerously threatened by climate change and human activity”, says Professor Wiedenmann. “Reef organisms can provide us with potential life-saving tools and products, so we need to act now and protect this pharmaceutical treasure chest.”