Even though I don’t live in the tropics and am not physically able to dive, I can still stare at coral reefs all day long.
Reefs are the vibrant, bustling cities of the sea. Though they cover less than 1% of the ocean floor, they support a staggering 25% of all marine life. But these vital ecosystems are in trouble, facing threats from warming waters that cause coral bleaching. In this stress reaction, corals expel the algae living in their tissues, leaving them pale and vulnerable to predation.
For a long time, restoration meant slow, manual work. But today, a wave of incredible technology is giving us a fighting chance to restore these natural wonders on a scale we never thought possible.
In Australia, scientists have repurposed a robot originally designed to hunt coral-eating starfish and given it a new, life-giving mission. Meet LarvalBot, an underwater drone that acts like a “crop duster” for the reef, gently dispersing millions of microscopic baby corals (larvae) over damaged areas. By collecting spawn from corals that have survived bleaching events, scientists can rear more heat-tolerant larvae in floating nurseries before sending them out with LarvalBot to re-seed the reef.
But where do these baby corals land? That’s where 3D printing comes in. Companies like Archireef are creating incredible, custom-designed “Reef Tiles” from natural materials, such as terracotta clay. These structures mimic the complex shapes of natural reefs, giving the free-swimming larvae a perfect, sheltered place to attach and grow. The results are astounding, with some projects reporting a coral survivorship rate of over 95%.
Finally, how do we keep these newly settled corals healthy? Corals are animals that need to eat. Scientists have developed a brilliant tool called the Underwater Zooplankton Enhancement Light Array (UZELA). It’s an autonomous, programmable light that attracts zooplankton—the microscopic animals that corals feed on—directly to the reef. Studies have shown that this can boost a coral’s feeding rate by 10 to 50 times, providing them with the energy they need to grow strong and resilient.
