Larvae-Attracting Gel Could Help Restore Destroyed Coral Reefs

We can’t leave coral reef restoration to chance. To help coral larvae settle in damaged reef areas, researchers developed an algae-based gel that actively attracts them.

The Hidden Builders of Coral Reefs

Although many people assume coral polyps produce all the calcium carbonate in reef structures, crustose coralline algae actually produce a significant portion of that material.

These algae not only reinforce reef structure but also create favorable conditions for free-swimming coral larvae to attach. Once they settle, the larvae turn into polyps and begin producing their own calcium carbonate, contributing to reef growth.

This mutual relationship benefits both coral and algae. While the reef offers physical protection to the algae, coral polyps release ammonia, which the algae use as a nutrient. To attract passing larvae, the algae release chemical compounds called metabolites that serve as natural signals.

Introducing SNAP-X: A Gel to Boost Coral Recovery

A team of scientists led by Dr. Daniel Wangpraseurt from UC San Diego’s Scripps Institution of Oceanography has now embedded those compounds into a gel called SNAP-X, designed for direct application on degraded reefs. According to the team, the substance can increase coral larval settlement by up to 20 times compared to untreated surfaces.

Because these metabolites would quickly dissipate if released directly into the water, the researchers encapsulated them in durable silica nanoparticles.The researchers then suspended these nanoparticles in a biocompatible liquid blend of gelatin methacrylate and polyethylene glycol diacrylate.

How SNAP-X Works Underwater

When sprayed or brushed onto surfaces—such as dead coral—and exposed to UV light, the mixture forms a hydrogel. This gel adheres to the surface for up to a month, even in flowing water, and slowly releases the larvae-attracting particles over time.

In initial lab experiments, SNAP-X led to a sixfold increase in larval settlement. Later trials, which better mimicked real reef water flow, saw results jump to a 20-fold increase.

Wangpraseurt believes researchers can adapt the technology for other coral species with some adjustments, even though testing has so far involved only one species.

“I see this material as a breakthrough that can make a real difference in coral restoration,” he says. “Biomedical researchers have spent years developing nanomaterials for drug delivery, and now we’ve been able to apply that knowledge to marine conservation.”

Read the original article on: New Atlas

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