When we think of coral reefs, we typically picture the colorful shallow-water reefs found in tropical destinations. But hidden in the cold, dark depths of the ocean lies an equally important and fascinating ecosystem: deep-sea coral.
A Different Kind of Coral
Unlike their shallow-water cousins, deep-sea corals do not rely on symbiotic algae for nutrition. Instead, they filter feed on tiny particles drifting down from the surface. These corals can be found at depths ranging from 200 to over 6,000 meters.
Deep-sea coral ecosystems support hundreds of species, including commercially important fish, crabs, and sponges. They grow incredibly slowly – some colonies are over 4,000 years old – making them extremely vulnerable to damage.
Threats to Deep-Sea Corals
Bottom trawling is the greatest threat to deep-sea coral. A single pass of a trawl net can destroy coral colonies that took millennia to grow. Climate change and ocean acidification also pose significant risks, as these corals are adapted to stable, cold conditions.
Our Research Efforts
The Ocean Conservation Alliance is working with partners to map and protect deep-sea coral habitats. Using remotely operated vehicles (ROVs) and advanced sonar technology, we are discovering new coral gardens and advocating for their protection.
In 2025, our team documented a previously unknown coral reef off the coast of Chile, spanning over 100 square kilometers. This discovery led to the creation of a new marine protected area.