US scientists create gel that draws coral babies in drive to save reefs

In efforts to give life to degraded reefs, researchers from San Diego have created a gel that draws coral larvae to settle on dying or artificial reefs.

- Shabana Begum

The gel emits a scent that corals associate with healthy reefs. Coral larvae are picky about where they attach to, and if they fail to settle, they will be eaten by predators or washed out to sea.

When researchers from the University of California (UC) San Diego's Scripps Institution of Oceanography coated a man-made surface in the lab with the gel, it drew about 20 times more coral babies than an untreated surface.

The tank experiment involved one Hawaiian coral species - the stony Montipora capitata.

While more studies are needed to prove that the gel can work with other corals, this innovation is among several that have emerged to save the world's reefs, which are threatened by climate change and habitat destruction.

Singapore is home to a variety of corals, including more than 250 species of hard corals.

The reefs here serve as habitats for more than 100 species of reef fish and about 200 species of sea sponges, as well as rare and endangered seahorses and clams, among other marine life.

Other research includes running electricity through corals to speed up their growth - which has been trialled in Singapore - and "coral IVF". In the latter initiative, scientists in Australia collect the eggs and sperm of resilient corals and rear the larvae in inflatable pools, before releasing them to reefs.

The world's coral reefs are facing the most prolonged and widespread bleaching in recorded history, with more than 80 per cent affected by marine heatwaves. When corals get stressed by high ocean temperatures, they expel the algae that give them their striking colours and turn a ghostly white, which is known as bleaching.