Fish displaced by rising water temperatures or natural disaster may soon be getting 3D-printed coral homes, thanks to researchers at the University of Delaware (UD).

Danielle Dixson and Emily Ruhl, both of UD, devised a technique for 3D printing artificial coral to protect fish from larger predatory species and coral reefs from the ravages of warm water temperatures, ocean acidification, human interference, natural disaster and coral bleaching, which is the expulsion of critical algae from the coral’s tissue that turns coral fully white.

To create the artificial coral replicas, Ruhl and Dixson 3D-printed artificial coral composed of filaments including polyester, cornstarch and a cornstarch-stainless steel mixture. Of the different versions, the cornstarch and the cornstarch-stainless steel mixtures were biodegradable, according to the team.

The researchers tested the artificial coral on damselfish, which are small reef fish, and on mustard hill coral larvae. Placed in a fish aquarium among four 3D-printed artificial coral replicas and one coral skeleton of calcium carbonate, the damselfish did not indicate a preference for one habitat, nor did they prefer a material. Instead, their behavior went unchanged.

The team also observed that the mustard hill coral larvae, which are critical coral reef building blocks without which coral reefs cannot be rebuilt, settled on both the genuine and artificial coral surfaces without demonstrating a preference. Researchers predict that if the larvae take to the artificial coral, they may promote the growth of calcium carbonate around the artificial structures, which will eventually biodegrade.

Going forward, Dixson and Ruhl will continue to test the 3D-printed habitats and are currently conducting an experiment in the waters around Fiji where they have deposited 3D-printed cornstarch filament tiles. That research is ongoing.

The results from the 3D printed artificial coral study appear in the journal Plos One.