Oceanographers have discovered two pristine deep-sea coral reefs near the Galapagos Islands and mapped two undiscovered seamounts off the coast of Ecuador.

The larger of the two cold-water reefs is more than 2,600 feet (800 meters) long, according to the release. Both reefs lie 300 meters below the ocean surface in the Galapagos Marine Reserve and feature a rich variety of stony coral species that have thrived there for thousands of years.

“The Galapagos Marine Reserve is an area of ​​outstanding biological importance,” Stuart Banks, senior marine scientist at the nonprofit Charles Darwin Foundation, said in a statement. “Finding such deep, long-lived reefs takes us important steps towards protecting hidden dimensions of ocean diversity and understanding the role deep habitats play in maintaining our ocean health.”

The researchers found the coral reefs during a 30-day expedition to study reef ecosystems around the Galapagos Islands. They used a remotely operated vehicle (ROV) to capture images of colorful species that support other life forms, such as crustaceans, anemones, brittle stars and sea urchins.

The expedition also confirmed the presence of two seamounts in the marine reserve that scientists had previously discovered using satellite data. The team mapped the objects using a laser scanner, which creates extremely high-resolution maps. These maps are so detailed that you can make out the animals living on the seabed one by one.

The researchers also created detailed maps of newly discovered coral reefs covering vertical cliffs at depths of 370 to 420 m (1,200 to 1,400 feet). But these aren’t the first cold-water reefs found in these waters: In April, scientists documented the first deep-sea coral reef found atop a previously undiscovered seamount in the Galapagos archipelago.

The expedition also traveled to the sheltered waters of a remote volcanic island known as Cocos Island, in the northeast of the Galapagos Archipelago. There, the team observed more deep-sea corals covered in eggs, according to the statement.

“These exciting new findings continue to support important research to better manage existing and future marine protected areas in the region,” Banks said.