June 30, 2021

In first-ever deep-sea survey on both ends of the Salas y Gómez and Nazca ridges, researchers found significant marine biodiversity

Arlington, VA (June 30, 2021) – A new study found a unique deep-sea ecosystem and recorded over 120 species along the Salas y Gómez and Nazca ridges in the southeastern Pacific Ocean, many of which are extremely fragile or not known to inhabit anywhere else. This study, published today in the scientific journal PlosOne, is the latest of only a few scientific explorations in the deep waters of this region, which until now has been largely unexplored. 

The Salas y Gómez and Nazca ridges boast a rich marine biodiversity with one of the highest rates of unique species on Earth. Nearly half the species found in this region live nowhere else on the planet and scientists have identified these ridges as one of the most ecologically important areas globally. Still, most of the deeper waters in this remote region remains a mystery to science.

“The Salas y Gómez and Nazca ridges are one of the most unique biodiversity hotspots on Earth, and we’ve only just begun to explore it,” said Alan Friedlander, lead author of the study and chief scientist for National Geographic Pristine Seas. “This region needs to be protected using the best available conservation measures if we hope to preserve its extraordinarily unique biodiversity.” 

The study was the first to systematically survey animal inhabitants along both ends of the Salas y Gómez and Nazca ridges, two underwater mountain ranges that stretch across 1,800 miles. The study was conducted by a team of scientists from Conservation International, the National Geographic Society, Universidad Católica del Norte (Chile), University of Hawaiʿi and University of Texas Rio Grande Valley, as part of the Coral Reefs on the High Seas Coalition, a global alliance of partners that aims to generate the science, communication and support to conserve coral reefs on the high seas. 

Collectively, the science team identified over 120 species along the seafloor, 14 of which are considered indicator species for vulnerable marine ecosystems – these species are particularly fragile to human impacts. 

“We recorded a wide range of deep-sea corals and sponge species,” said Daniel Wagner, technical advisor of ocean science at Conservation International and co-author of the study. “These species are much like the redwood trees of the ocean – they are not only slow-growing and long-lived, but they also provide critical habitats for many other species.”

Among the recorded 58 invertebrates and 65 fish species – ranging from various types of corals, sponges, shrimp, sharks, fishes, eels – many have only ever been found within the Salas y Gómez and Nazca region. Some of the rarest species recorded by the study were: 

  • A neon-colored damselfish (Chromis mamatapara) discovered just last year and to date only known from the islands of Rapa Nui (Easter Island), Salas y Gómez and adjacent seamounts
  • A newly discovered beardfish (Polymixia salagomeziensis), which has only ever been recorded from the Salas y Gómez Ridge
  • The deep-dwelling moray eel (Gymnothorax bathyphilus), found only in the waters of the study region 
  • The red sploge fish (Plectranthias nazcae) a type of deep-sea bass found only in the reef ecosystems along the Nazca Ridge for which it is named

Due to the location and large size of the Salas y Gómez and Nazca ridges, international collaboration will be key to protecting it. While some of the ridges’ underwater mountains fall within the national waters of Chile and Peru, over 73% of the area lies beyond national jurisdiction in the high seas. If left unprotected, the region faces threats from overfishing, seabed mining, pollution and climate change. 

Due to the remote location and great depth, the Salas y Gómez and Nazca ridges have remained relatively lightly impacted. To date, commercial fishing has been limited and seabed mining has been absent. If protections are instituted now, these unique ecosystems can remain intact. 

“The remoteness of this region has sheltered its unique biodiversity from many human impacts,” said Wagner. “However, future climate change impacts in this region are predicted to be substantial, so we must act now.” 

The region surrounding the Salas y Gómez and Nazca ridges has been recognized as a prime candidate for conservation measures by several international organizations including the Convention of Biological Diversity, the Global Census of Marine Life on Seamounts, the Global Ocean Biodiversity and others. This new study further confirms that the deep-sea biodiversity of this region is equally significant and vulnerable to that of shallower waters and should therefore be protected using the best available conservation measures. 


About Conservation International Conservation International works to protect the critical benefits that nature provides to people. Through science, partnerships and fieldwork, Conservation International is driving innovation and investments in nature-based solutions to the climate crisis, supporting protections for critical habitats, and fostering economic development that is grounded in the conservation of nature. Conservation International works in 30 countries around the world, empowering societies at all levels to create a cleaner, healthier and more sustainable planet. Follow Conservation International's work on Conservation NewsFacebookTwitterInstagram and YouTube.