'Alien-like' marine life found on underwater mountains includes 100 new species

When you digest the fact that humans know less about the seamounts dotting our planet’s oceans than about the vast expanse of outer space, it might take a moment to sink in. Only a fraction of these grandiose underwater mountains have even been mapped.

The 14,500 seamounts mapped to date are projected to be a mere fraction (less than 1%) of the actual total. This staggering disparity highlights how much of our oceanic world remains unexplored.

A dormant volcano teeming with life

The story of the Davidson Seamount is just one example. Its name is a misnomer of sorts, as it is an underwater inactive volcano that is nestled off the Californian coast.

Discovered way back in 1933, this expansive entity covers 25 miles (40 kilometers) and has been dormant for the last 9.8 million years.

Despite the seeming desolation its description might suggest, this “dead” volcanic structure is buzzing with life.

It’s home to magnificent coral reefs and extensive deep-sea octopus gardens, and offers a thriving ecosystem for marine animals including whales.

The unique biodiversity of the Davidson Seamount has made it a vital area for marine research that has focused attention on the ecological importance of these underwater mountains.

The mysteries of underwater mountains

The Davidson Seamount, however, supports just a tiny fraction of the underwater splendors that remain unexplored.

Take a voyage to the Canadian coast where another ancient, and notably active, volcano was discovered. The site was found to be covered in millions of colossal eggs, laid by the ethereal Pacific white skates.

For comparison, the previously known nursery of this species (in the Galapagos) had a mere sprinkling of eggs, as noted by a marine biologist at Fisheries and Oceans Canada.

The most recent voyage of discovery was led by experts from the Schmidt Ocean Institute. The team unearthed a staggering 1.5-mile-high (2.4 kilometer) seamount, accompanied by three others in the southern Pacific.

One of these seamounts, situated along the Nazca ridge off the Chilean coast, offered a vision so astonishing that the explorers were left awe-struck.

They found themselves amidst a multitude of species that had never been seen by human eyes, which led them to draw parallels with a journey “through the cosmos.”

Diverse marine species revealed

The month-long expedition proved highly fruitful. Unexpected residents of these depths were identified, including ghostly white sponge gardens, flying spaghetti monsters (a type of colonial hydrozoan), Casper octopuses, millennium-old glass sponges and vast forests of bamboo corals.

A fascinating fact about the glass sponges is that they build intricate, cylindrical structures using spiky “spicules” and often house crustaceans until their death.

This unique interaction between different species creates a mutual relationship, where the captivated crustaceans clean the sponges and breed within them.

Vibrant marine life on underwater mountains

The expedition revealed a vibrant and unexpected color palette in the depths of the Chilean seamount, with numerous species displaying bright red hues.

Strange as it may seem, this coloration acts as a form of invisibility cloak in the depths where red light is absorbed first, leaving the species to appear black in the depths.

Alongside these species were cactus-like sea urchins and marine sponges that towered to human height.

A consortium of scientists from Ocean Census, who led the expedition planning, noted that this region of the southern Pacific exhibited a high level of endemic species – those that cannot be found anywhere else in the world.

Seamounts in a changing climate

The significance of seamounts extends beyond hosting unique and vibrant marine life.

According to the National Oceanic and Atmospheric Administration, seamounts are emerging as vital sanctuaries for marine life amidst the growing threats of climate change and warming oceans.

Their steep surfaces offer the right conditions for cold-water corals, sponges, and other surface-growing creatures.

The currents around these seamounts stimulate an upsurge of nutrients from the ocean floor, triggering phytoplankton growth that supports food chains within the marine world.

Additionally, these nutrient-rich areas act as hotspots for biodiversity, supporting species that are often rare or endemic to these environments.

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