Underwater Caves Could Offer a Lifeline for Mediterranean Corals

Published 5 days agoon October 1, 2026

Underwater caves could provide vital refuges for Mediterranean corals as warming seas and increasingly frequent marine heatwaves take their toll, new research has found.

Colonies inside the cave. Image Julia Sarda/UndResCoral

Scientists studying white gorgonian corals (Eunicella singularis) at Cova de la Vaca, a submerged cave in Spain’s Medes Islands, discovered striking differences between colonies living inside the cave and those exposed to conditions outside.

The team studied colonies at depths of around 19–21 metres, monitoring temperature and light levels and examining coral mortality, reproduction and physiological responses.

Outside the cave, where corals experienced more light and slightly higher temperatures, 61% of colonies surveyed were dead. Inside, mortality was 17 times lower, with 85% of colonies showing little or no affected tissue.

Corals sheltering within the cave also showed greater reproductive output and were generally larger than those outside.

Researchers believe the darker, slightly cooler conditions inside Cova de la Vaca may reduce the combined stress caused by high temperatures and intense light during marine heatwaves. Other factors, including water movement and food availability, may also contribute.

The findings suggest that some submarine caves could act as natural climate refuges, helping vulnerable marine species withstand the effects of warming seas.

However, researchers say protecting these habitats will be important if they are to continue providing sanctuary as ocean temperatures rise.

Image credit: UndResCoral

Source: Frontiers in Marine Science

Jane Morgan

Jane’s lifelong love for the ocean began in childhood and has shaped the course of her life and career. After learning to dive in 1991, she spent much of the '90s teaching scuba and working on marine conservation projects in the Philippines and Borneo. A chance encounter with a film camera on a dive trip to Egypt in 2001 ignited a passion for underwater photography, inspiring her to leave the corporate world and pursue a full-time career in dive travel and photojournalism. Since then, her work has been published in a wide range of national and international magazines, books, and newspapers. She has filmed underwater for the BBC, judged major photography competitions, and received numerous accolades—including the prestigious Plongeur d'Or at the Festival Mondial de l'Image Sous-Marine. In 2009, Jane became a freelance photojournalist, and in 2011 completed a BA (Hons) in Marine and Natural History Photography at Falmouth University, where she now works as a Dive Safety Officer. Based in Cornwall, Jane dives locally year-round and is passionate about showcasing the rich marine life found in UK waters. As a proud ambassador for Dynamic Nord and Fathoms Free, she actively supports marine conservation initiatives and advocates for ocean protection through her storytelling. In her newest role with Scubaverse, Jane combines her love of travel, diving, and storytelling—sharing experiences from around the world to inspire others to explore, protect, and connect with the underwater world.