Famous sea monsters have long been the stuff of fish-stories, warnings, and mariners’ tales. From dangerous drawings on early maps to souvenirs sold by the shores of Loch Ness, the tales of sea monsters have intrigued and frightened humans for centuries. As human knowledge of marine biology increases, many of the sea monsters our ancestors feared have become mundane, even harmless, realities. Yet some, like the giant squid, Loch Ness, and Lake Champlain Monsters seem to defy our attempts to understand and identify them, leaving the waters of the world still open to fantastical stories.
The Kraken, a many-tentacled, ship-eating sea monster, has been recorded in Norse history since the mid-13th century. Large enough to be mistaken for an island, the Kraken was said to be able to pull a ship to the bottom of the ocean. Descriptions for this sea monster ranged somewhere between squid and octopus, and experts now believe the Kraken legend is based on real stories of Architeuthis, the very real and very large giant squid. These real-life sea monsters have lent itself to legend quite easily, as they are famously elusive. Not until 2006 was a live giant squid ever recorded on film, although carcasses have washed up on beaches for many years.
The other depiction of the Kraken as a giant octopus has never truly been debunked. The largest specimen of octopus ever found measured at 23 feet (7 m) and weighing 156.5 lb (71 kg.) Yet stories of truly giant octopus continue, with some claiming carcasses have been discovered, just not correctly identified. The St. Augustine Monster, an enormous carcass of unidentifiable animal tissue, is considered by some to be positive evidence of a giant octopus.
Stories of mermaids or Sirens have existed since at least 1000 B.C.E., and give these half-fish, half-human creatures a murky reputation. Sirens are true sea monsters based on Greek mythology, who would lure sailors by singing to them before drowning them. Mermaids are sometimes given a gentler portrayal, occasionally given credit for rescuing shipwrecked sailors. The modern explanation for mermaid sightings is that the viewers were seeing manatees or dugong. Although theories cannot quite explain mistaking the cow-like visage of a manatee for the long haired, beautiful mermaid, they point out that the manatee and dugong were given the scientific name Sirenia and were often referred to as mermaids by sailors.
Stories of surviving plesiosaurs have given rise to the belief in a class of creatures often called “lake monsters.” These rarely seen, not entirely disproved sea-monsters include the Loch Ness Monster, the Lake Champlain Monster, and the Lake Okanagan Monster, also called Ogopogo. Evidence for lake monsters dates back hundreds of years, and sightings are based on eyewitness accounts and occasionally photographs or videos. The existence of lake monsters is taken so seriously, several scientific studies have been undertaken to discover if they are real or not. No conclusive evidence has ever been found.
In ancient maps, sea monsters frequently appear as illustrations. These creatures are variously depicted as resembling snakes, alligators and sharks. To ancient mariners, actual sea creatures did pose real danger in case of shipwreck, but most sea-monsters were eventually discovered to be mostly harmless whales, dolphins, and eels. Nevertheless, it is undeniable that some reports of sea monsters have not yet been explained. Human knowledge of the depths of the oceans is far from complete, and it is possible the waters of earth hold sea monsters we have not yet discovered.