Scientists Discover Active Underwater Volcano Serving As A Massive Nursery For Deep Sea Eggs

A routine deep-sea expedition off the coast of Canada has uncovered a geological and biological marvel, revealing that a mountain long presumed to be an extinct volcano is not only active but serves as a massive nursery for marine life. Located nearly 1.5 kilometers beneath the surface, the seamount rises 3,600 feet (1,100 meters) from the seafloor, providing a warm, mineral-rich sanctuary for thousands of Pacific white skates (Bathyraja spinosissima).

A Hidden Volcanic Incubator

The research team, led by Fisheries and Oceans Canada biologist Cherisse Du Preez, initially anticipated exploring a cold, dormant volcanic structure. Instead, they discovered a thriving ecosystem fueled by active hydrothermal fluids. The volcanic heat appears to create an ideal environment for deep-sea corals to flourish, which in turn provides a stable habitat for the skates to deposit their eggs.

This discovery highlights a significant ecological strategy. While deep-sea environments are typically frigid, the warmth generated by this underwater volcano appears to act as a natural incubator. Similar behaviors were previously documented in 2018 near the Galápagos Islands, where researchers identified skate eggs clustered near hydrothermal vents, suggesting that this species relies on geothermal warmth to support its reproductive cycle.

An Unprecedented Scale of Life

The sheer density of the site caught the research team by surprise. While previous nurseries, such as the one found in the Galápagos, contained only a few dozen eggs, this Canadian site hosts an estimated 100,000 to one million eggs. These large, rectangular capsules—often referred to as “mermaid purses”—measure approximately 1.5 feet (0.5 meters) in length.

“I’d estimate the summit of the seamount, which was covered in eggs, had, I don’t know, 100,000? A million?” Du Preez noted in an interview with Live Science. She described the location as “a really special place on top of a really special place.”

Biological Advantages of Geothermal Heat

Pacific white skates, which can reach lengths of up to 6.5 feet (2 meters), are generally enigmatic creatures that inhabit depths between 2,600 and 9,500 feet (800 to 2,900 meters). The expedition captured the first recorded footage of a female skate depositing her eggs, offering researchers a rare look into their life cycle. Scientists hypothesize that the elevated temperatures at the summit significantly shorten the development time of the embryos, which typically takes about four years.

By accelerating the gestation period, the volcanic heat increases the likelihood of juvenile survival. Once the young skates hatch, they use the coral-rich summit as a nursery, gaining strength before migrating into the deeper ocean. As the site currently lacks formal protection, the team plans to continue monitoring the area to ensure the long-term viability of this critical habitat against potential environmental pressures and commercial fishing activities.