Corals and sea anemones turn sunscreen into toxins – understanding how could help save coral reefs

What is the News?

Researchers have identified a mechanism by which oxybenzone – a common sunscreen component – may be hastening the demise of reefs. 

What is Oxybenzone?

Oxybenzone is the sun-blocking agent in many sun creams. Its chemical structure causes it to absorb UV rays, preventing damage to skin cells.

But it has attracted controversy in recent years after studies reported that it can damage coral reefs. These concerns have led to some beaches in Hawaii, Palau and the US Virgin Islands, banning oxybenzone-containing sunscreens. 

However, the mechanisms by which oxybenzone does harm have largely remained a mystery, making it difficult to ensure that sunscreen components proposed as alternatives are truly safer for corals.

To find out the mechanism, Stanford researchers conducted a study.

What did the researchers find out?

The scientists used sea anemones and mushroom corals as models and exposed them to oxybenzone in a tank filled with artificial seawater.

In one of the experiments, this treatment was combined with simulated sunlight, which saw all anemones die off within 17 days. In a parallel experiment where there was no sunlight, the creatures all remained viable. 

This runs counter to what the scientists expected from oxybenzone which is designed to absorb light energy and dissipate it as heat to prevent sunburn.

Hence, these findings suggest that sunscreen pollution and climate change combined could be a greater threat to coral reefs and other marine habitats.

Source:  The post is based on the article “Corals and sea anemones turn sunscreen into toxins – understanding how could help save coral reefs” published in Down To Earth on 9th May 2022