I've heard rumors about gargantuan animals living in the deepest parts of the sea that we haven't been able to explore properly yet. One such tale was of deep rumbling sounds that could come from the belly of an enormous beast. Is there any truth to these stories? Are there large enough stretches of unexplored ocean to reasonably suggest there might be unknown animals there?
Illustration by Slug Signorino
You bet. While finding new megafauna is tougher than it used to be, there are still remote reaches of the globe where you might stumble across an animal nobody’s ever seen before. However, be forewarned: don’t get your hopes up if it goes “bloop.”
That’s the lesson we draw from those rumbling ocean sounds you refer to, which were recorded by underwater microphones in the South Pacific in 1997. The Bloop, as it was soon nicknamed, sounded like Godzilla with a bad case of gas. Unfortunately for cryptozoologists, the National Oceanographic and Atmospheric Administration declared it was most likely vibrations from the breaking of Antarctic sea ice. To the lay ear the sound files NOAA provided don’t sound much alike, possibly because the Bloop for some reason was sped up to 16 times its original frequency, whereas the comparable sea ice recording was sped up only three times. However, the people at NOAA work for the government. One presumes they know what they’re doing.
But let’s get to the heart of the matter: yes, there are large stretches of ocean where unknown megafauna could be hiding. NOAA estimates 95 percent of the sea remains unexplored. Since the ocean covers 70 percent of the Earth’s surface, that means almost two-thirds of the planet is as mysterious to us as it was in Magellan’s day.
The immense mid-ocean ridges formed by plate tectonics, which at 40,000 miles are by far the longest continuous mountain range in the world, weren’t discovered until the 1950s. The amount of properly mapped seafloor in the public domain is 2 to 3 percent, and even when you add in what’s been mapped by the world’s navies and kept secret, the figure is likely no more than 10 percent. Bear in mind this is strictly topographical mapping, to keep submarines from crashing into underwater mountains. (The USS San Francisco did this in 2005, killing one sailor.) So we have no systematic account of what’s living in even that 10 percent.
A 42-day expedition to the Philippines in 2011 found hundreds of new marine species, including a type of swell shark (which can inflate itself with water) and a pancake-shaped sea slug. The ocean around Antarctica is vast, deep, and poorly explored, and more than half the deep-water creatures known to live there have been spotted only once or twice.
Most newly discovered species don’t qualify as gargantuan, but some are pretty big. The megamouth shark, undiscovered till 1976, can reach 18 feet in length. The giant squid, long believed to be the largest invertebrate in the world, had never been seen alive till 2004, when a specimen more than 25 feet long was caught on camera; meanwhile an apparently even bigger critter, the colossal squid, remains elusive. Researchers from the massive Census of Marine Life project reported in 2010 that even though there are 250,000 known ocean species, perhaps 750,000 more await discovery, to say nothing of more than a billion types of microbes.
But it’s not just the sea that holds mysteries. The forested mountains of the Sierra de Maigualida region of Venezuela, covering more than 4,500 square miles, are almost entirely unexplored. The same is true of large swaths of Antarctica, most surveys having been done from aircraft. Antarctica also features enormous freshwater lakes locked deep under the ice. The largest, Lake Vostok, holds about 1,500 cubic miles of million-year-old water, potentially harboring prehistoric creatures unlike anything else we’ve encountered.
Megafauna could be hiding in caves. By some estimates, even in well-explored regions like the U.S. only 50 percent of caves have been investigated, and worldwide it’s maybe 10 percent. However, big critters would have big appetites, and a cave, lacking photosynthesis, is necessarily a low-energy environment. As a result, most new wildlife discoveries in caves are bug-scale.
Personally I’d stick with the tropics. The Vu Quang ox of Vietnam wasn’t proven to exist until 1994, when a live specimen was captured. Soon afterward, a new species of deer was discovered in the same Vietnamese rain forest. In fact, since 1993 more than 400 new species of mammal have been discovered, about 10 percent of the total mammalian species known. Most of these are small (lots of rodents and bats), but 40 percent are large and distinctive. Some researchers think we’ll eventually find another 100 to 200 new mammal species, most of them in North and South America.
Are there swarms of enormous beasts out there, waiting for a doughty explorer to find them? Probably not. But just because we’ve got Google Earth doesn’t mean we’ve discovered all there is to know about the world.
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