An international team of researchers has discovered a colorful array of glowing corals in deep water reefs located in the Red Sea, and their efforts could make it possible for these pigments to be developed into new imaging tools for use in biomedical applications.
View the video of the rainbow corals here.
Scientists from the University of Southampton in the UK, the Interuniversity Institute for Marine Sciences (IUI) and Tel Aviv University in Israel, and collaborators from other parts of the world studied corals at depths of more than 50 meters. They found that many glow brightly in an array of different fluorescent colors, ranging from green to yellow to red.
The discovery of these colorful corals in such deep water was unexpected; the researchers said in a statement, as coral found in shallow waters in the same reef were just green fluorescent pigments. Their findings have been published online in the journal PLOS One.
Research could help protect threatened coral reefs
Dr. Jörg Wiedenmann, a professor of biological oceanography at the University of Southampton and the head of the university’s Coral Reef Laboratory, told redOrbit that a substantial amount of work on the new paper was completed at the International Mesophotic Workshop 2014 held at the IUI in Eilat, the southernmost city in Israel.
He explained that mesophotic coral reefs (those that extend from 100 feet to 330 feet and are marked by low availability of light for photosythesis) are “less well studied because they are beyond the depth limits for normal SCUBA divers.” The workshop focused on efforts to explore these deep-water reefs, and he was invited as an expert in the field of coral fluorescence “to lead a project exploring this exciting optical phenomenon in deep water corals.”
“The abundance and diversity of these fluorescent protein pigments support the notion that they can fulfill alternative biological functions for the corals apart from the sunscreening effect for the symbiotic algae which some members of this pigment family have in shallow water corals,” Dr. Wiedenmann explained to redOrbit. The findings will help researchers understand the structure of coral communities, and how they adapt to life in different depths of water.
That information, he said, “is important to guide management efforts to protect coral reefs,” which “are threatened by climate change, overfishing, enrichment with nutrients and sediments, and destructive coastal and maritime developments. If we don’t learn to take better care of them and the rest of our planet, we risk that they may vanish…within the lifetime of our children.”
Pigments could potentially also have other biological functions
Furthermore, the authors report that the diversity of pigments discovered in these mesophotic corals could enable some of the to be rendered into new types of imaging tools for biomedical and pharmaceutical research. They also noted that they are in the process of exploring other potential biological functions that these pigments could fulfill.
“In shallow water corals, some members of the fluorescent protein family protect their symbiotic algae from excess sunlight. Their production is tightly controlled by the corals and dependent on the light intensity,” Dr. Wiedenmann told redOrbit. “The more light they get, the more colorful they become. In contrast, several fluorescent pigments from mesophotic are produced constantly by the corals at high levels.”
“Such an energy investment makes sense only if it is coupled to a biological benefit,” he added. “Since corals and their symbionts do not suffer from excess light at these depth – on the contrary they struggling to receive enough light – a sunscreening function can be excluded.”
It is possible that they could enhance the amount of light available for the symbiotic algae, but the underlying mechanisms behind this are not yet fully understood. Dr. Wiedenmann hopes that his team’s work will shed new light on their function.