Deep-Sea Oases: The Mysterious Life of Seamounts
Far below the surface of the world’s oceans lie thousands of underwater mountains known as seamounts. Rising from the seafloor like drowned volcanoes, they can reach thousands of metres in height—taller than many mountains on land—yet their summits never break the surface.
These giants are born of fire. Most seamounts began as volcanoes, formed where molten rock burst through the oceanic crust at weak points or along tectonic boundaries. Over time, many became dormant, sculpted by currents and covered in marine life. Others, like those in the Pacific “Ring of Fire,” remain active, still growing and occasionally shaking the sea above them with tremors.
Oases in the deep
What makes seamounts so mysterious is how little we know about them. Scientists have identified 14,500 seamounts, but estimate there are many more worldwide. Only a small fraction has been explored. Many are home to unique ecosystems that depend on the upwelling of nutrient-rich waters around their slopes. These currents attract plankton, fish and large marine creatures—sharks, tunas and whales—making seamounts oases of life in the deep ocean’s desert.
Life on the hidden peaks
Recent expeditions, using submersibles to explore some of the deep ones, and using mapping technologies, have revealed coral gardens hundreds of years old, rare deep-sea sponges and strange new species that thrive in perpetual darkness. Each seamount seems to host its own distinct community—as if every one were a separate island in the vast deep-sea realm.
Fragile and unseen
Yet, despite their importance, seamounts face growing threats. Deep-sea trawling can destroy their fragile corals in minutes, and mining companies are eyeing their mineral-rich crusts. Because most seamounts lie in international waters, they are beyond the protection of any country.
Silent sentinels of the deep
Still, these hidden mountains continue to stir curiosity and wonder. But for now, they keep most of their secrets as silent sentinels of the deep, guarding the stories of Earth’s fiery past and the life that flourishes in its shadowed depths.
Ethologist Ila France Porcher, author of The Shark Sessions and The True Nature of Sharks, conducted a seven-year study of a four-species reef shark community in Tahiti and has also studied sharks in Florida with shark-encounter pioneer Jim Abernethy. Her ethological observations, the first of their kind, have yielded valuable details about the reproductive cycles, social biology, population structure, daily behaviour patterns, roaming tendencies and cognitive abilities of sharks. Visit: ilafranceporcher.wixsite.com
