The expedition was led by the Schmidt Ocean Institute, in partnership with Ocean Census and the University of New Hampshire’s Center for Coastal and Ocean Mapping/Joint Hydrographic Center. The mission focused on exploring and mapping seamounts in international waters, about 900 miles off the coast of Chile.

Seamount discovery

One of the highlights was the discovery of a new seamount on the Nazca Ridge. This underwater mountain stands over 3,100m tall (1.9 mi) and hosts a flourishing deep-sea ecosystem. The team used advanced mapping technologies and an underwater robot to explore one of the mountain’s ridges, uncovering vibrant sponge gardens and ancient coral formations. These ecosystems are vital for marine biodiversity, providing essential habitats for a range of species, from brittle stars to king crabs.

The team also surveyed nine other seamounts in the region. One of the most significant finds was a pristine coral garden, spread across approximately 800 sq m, about the size of three tennis courts. This deep-sea coral habitat supports a wide variety of marine life, offering shelter to species like rockfish, king crabs and brittle stars.

Rare sightings

In addition to mapping these underwater features, the expedition made history by capturing the first video footage of a live Promachoteuthis squid. This squid genus is so rare that it had previously only been identified through a handful of specimens, some dating back to the late 1800s. Until now, scientists only knew of the species from dead specimens found in nets. The team also documented a Casper octopus, marking the first time this species has been sighted in the Southern Pacific, and encountered two rare Bathyphysa siphonophores, known as flying spaghetti monsters due to their appearance.

Significance of the findings 

The discoveries from this expedition highlight the richness and uniqueness of the deep-sea ecosystems in this region, contributing valuable knowledge about species that have remained largely unknown. The data collected could also play a crucial role in efforts to protect these underwater habitats, as the Nazca Ridge, along with the adjoining Salas y Gómez Ridge, is being considered for designation as a high-seas marine protected area. 

Co-Chief Scientist and Schmidt Ocean Institute Marine Technician Tomer Ketter said, “Our findings highlight the remarkable diversity of these ecosystems, while simultaneously revealing the gaps in our understanding of how the seamount ecosystems are interconnected. We hope the data gathered from these expeditions will help inform future policies, safeguarding these pristine environments for future generations.”