Just like us, corals breathe in oxygen and eat organic carbon. And just like us, as a byproduct of converting energy and oxygen in the body, corals produce reactive oxygen species (ROS), a family of chemical compounds that are naturally made by cells during cell division, while fighting off pathogens, and performing other physiological functions. But until now, it was unknown whether healthy, deep-sea corals produce a particular type of ROS, called superoxide (O^2-). Superoxide is a highly reactive ROS known for influencing ocean ecology, organisms' physiology, and driving chemistry in the ocean including the breakdown of carbon and the bioavailability of metals and nutrients.

 

A new study published in PNAS Nexus reveals, for the first time, that deep-sea corals and sponges do produce the ROS superoxide, meaning that these chemicals have a string of previously unknown effects on ocean life and chemistry in the deep sea. The authors prove that ROS are not only produced as a stress response, but as a fundamental part of its functioning. In the study, authors took direct measurements of superoxide in water closely surrounding corals, by bringing a one-of-a-kind deep-sea chemiluminescent sensor called SOLARIS, into the ocean over 2,000 meters deep, on board the Alvin submersible.