The discovery of an active underwater volcano off Canada’s Pacific coastline has revealed an unexpectedly vibrant deep-sea habitat centered around the life cycle of the Pacific white skate. Long believed to be dormant, the seamount was found to be warm, chemically rich, and covered in hundreds of thousands of large skate eggs. This finding provides an unusually detailed look at how a geological structure can influence animal reproduction in the deep ocean, particularly in regions where environmental conditions are typically cold, dark, and inhospitable. The interaction between volcanic heat and embryonic development has therefore become a focal point for researchers examining how life adapts in extreme marine environments.
How active underwater? Volcano shapes deep-sea life
During a recent deep-sea expedition, researchers mapped and explored a towering underwater volcano located about 1.5 kilometers beneath the ocean surface. The seamount rises roughly 1,100 meters above the surrounding seabed, forming a steep and complex structure that supports diverse marine life. The science team initially approached the site expecting to find a cold, inactive landscape, but the summit instead emitted warm, mineral-laden fluids that drifted into the surrounding water column. This venting activity indicated that the volcano is still geothermally active, contradicting earlier assumptions about its extinction.The combination of heat and mineral enrichment created a surprising habitat around the summit, which was covered in living corals and other organisms that typically rely on stable surfaces in otherwise barren deep-sea regions. The coral growth helped stabilize the summit’s terrain, creating pockets and ridges where biological communities could develop. As the remotely operated vehicles surveyed the area, the scientists not only confirmed ongoing volcanic activity but also began to notice irregular shapes carpeting the seafloor at the very top of the seamount.
How the Pacific white skate survives nearly 3,000 meters deep
The Pacific white skate, a large, deep-dwelling species that can reach up to two meters in length, is adapted to life far below sunlight. It is found at depths ranging from around 800 to nearly 2,900 metres, placing it among the deeper-living relatives of sharks and rays. Females of the species lay eggs enclosed within leathery capsules, sometimes referred to in common language as “mermaid’s purses,” though in this case the eggs are significantly larger than those of most other skate species.Each Pacific white skate egg case is roughly half a meter long, which is unusually large even among deep-sea egg-laying elasmobranchs. These eggs require several years to develop, and the prolonged incubation period is heavily shaped by environmental temperature. In cold water, metabolic processes slow considerably, making the deep ocean a challenging place for developmental biology. For this reason, the discovery of a warm deep-sea volcano immediately suggested a potential evolutionary advantage for skates nesting in the region.
Why this underwater volcano is covered in nearly a million giant eggs
When the science team’s cameras captured what lay across the summit, they were met with the extraordinary sight of hundreds of thousands of skate egg cases densely spread across the warm seafloor. The Livescience report described them as shaped like giant ravioli, closely packed in all directions. Initial counts based on the area surveyed suggested that there may be between several hundred thousand and nearly one million eggs on the summit, making the site one of the largest known nurseries of any deep-sea animal.Further into the dive, the researchers recorded a rare moment: a female Pacific white skate was seen laying an egg directly on the summit of the volcano. This observation provided essential behavioral evidence linking the species’ reproductive cycle with the seamount’s thermal activity. The warmth, although subtle compared to surface waters, appeared significant enough at depth to influence developmental rates. The biological team noted that even a modest increase in temperature can shorten the length of embryonic growth, potentially reducing the years-long incubation period associated with this species.The summit itself acted as a natural incubator. The coral garden surrounding the egg cases likely offered additional shelter against currents and predators, creating an unusually secure breeding environment in the deep sea.
Why skates rely on volcanic heat for their long incubation
Previous scientific research has explored the idea that hydrothermal vents may accelerate the development of skate embryos. The newly documented nursery strongly supports this concept, demonstrating how a warming effect from a volcano can shape reproductive success. Although deep-sea conditions usually slow down biological processes, the warmth detected on the summit provides a microhabitat where embryos can develop more efficiently.The Livescience report cites comments from the expedition’s lead biologist, who explained that the heat produced by the active volcano could effectively speed up the growth of the embryos, offering a survival advantage that would be impossible in surrounding cold waters. The presence of such a large number of eggs also suggests that skates may return repeatedly to this site, possibly recognizing it as a location that optimizes reproductive outcomes. Over time, this behavior could have ecological implications, potentially shaping population structures in the region.
Why this deep-sea skate nursery may need urgent conservation
Beyond its biological importance, the volcano-top nursery highlights a deeper ecological pattern. The coral garden, the geothermal activity, and the concentration of eggs create a rare intersection of geological and biological processes. According to the Livescience account, however, the site currently lacks legal protections despite its importance. Deep-sea fishing or human disturbance could disrupt the fragile nursery, especially given that skates, like many deep-sea species, reproduce slowly and have low population turnover.Researchers intend to return to the volcano to continue monitoring the site and gather more data on how temperature shapes embryo development. Long-term observation may help clarify how frequently skates use the nursery, how stable the volcanic heat remains over time, and how vulnerable the area is to external environmental pressures.Also Read | How the discovery of the ‘inner kernel’ may hold the answers to Neptune’s migration
