In recent years, fishermen in the Sea of Cortez have reported seeing a shark of truly frightening proportions. This creature is reported to be 20 to 60 feet long, weighing between 50,000 and 100,000 pounds, dark in coloration with a huge tail that whips to the surface before diving away quickly. The locals refer to the creature as the “Black Demon, and some believe that this creature could be a remnant population of Megalodon Sharks. In the MonsterQuest episode Mega Jaws, the team goes to the Sea of Cortez in search of this animal.
The History
On 15 July, 2008, fisherman Eric Mack was on his boat in the Sea of Cortez. His boat struck some large object that stopped it quickly in the water. As Mack tried to figure out what it was that his boat struck, he saw a large tail rising five feet out of the water and then dive away quickly.
Mack’s story is similar to that of many local fishermen on the Sea of Cortez. They report quick encounters with a massive shark that they refer to as the Black Demon. They blame the Black Demon for dismembered seals, sea lions and whales that have had massive chunks of flesh ripped from them.
Expert diver, Dale Pearson believes that the Sea of Cortez could be an excellent location for a mystery shark. The Sea of Cortez is located between mainland Mexico and the Baja Peninsula. This body of water is roughly 1,000 miles long and 200 miles wide and it can be as deep as 12,000 feet in spots. The diverse aquatic species in the Sea of Cortez could provide an adequate food supply for a large predator.
One explanation for these large shark sightings is that the eyewitnesses are seeing a whale shark. The whale shark is the largest shark known to be in existence today. It can grow up to 40 feet in length and weigh up to 20 tons. The diet of whale sharks is made up of plankton and krill and they are not a threat to larger animals. The size of a whale shark would match the eyewitness accounts but it would not account for the observed aggressive behavior or the attacks on sea mammals.
Another theory that many believe is that the witnesses are observing a relic population of megalodon sharks. According to Steve Alten, the author of “Meg: Hell’s Aquarium”, the megalodon was the largest carnivorous shark to ever live. It could be up to 70 feet in length and weigh up to 70,000 pounds. Alten says that you should imagine a great white shark the size of a tractor trailer truck to get the right impression.
Our knowledge of the megalodon shark comes from fossilized teeth that have been found throughout the world. Like other sharks the body would of had cartilage instead of bones, so the rest of the body would not fossilize. The tooth remnants are found to be 3 to 4 times the size of great white shark teeth. They can have a diagonal length of over 6 inches with sharp serrations along the edge. Most experts believe that the megalodon shark went extinct about 1.5 million years ago.
At least one expert disagreed with the timetable for megalodon extinction. In 1872, the HMS Challenger conducted a four year scientific expedition dredging and mapping the seafloor of the Pacific. Examples of megalodon shark teeth were found in the depths of the Mariana Trench. The Mariana trench is 1500 miles long, 40 miles wide and so deep that you could place Mt. Everest inside it without breaking the surface. The type of area that could easily hide an aquatic species. In 1959, Dr. W. Tschernezky of London’s Queen Mary College analyzed a megalodon shark tooth found by the Challenger expedition and estimated in to be only 10,000 years old. His method of dating was based on measuring the manganese dioxide deposits around the teeth and is widely questioned by most scientists. Supporters of the remnant population theory believe that Tschernezky findings show that it is still possible that the megalodon is still around today.
Most experts agree with Dr. Tom Demere, the Curator of Paleontology at the San Diego Museum of Natural History. He does not believe that it is possible for a remnant population of megalodon sharks to be alive in the Sea of Cortez. He points out that this type of shark did not inhabit these waters 2 million years ago so it would not make sense for them to be there today.
The Investigation
The MonsterQuest team undertakes the search for Megalodon in two parts. They will mount an expedition to the Sea of Cortez in search of the shark. The second part will be a reexamination of the megalodon tooth that Dr. Tschernezky identified as being only 10,000 years old.
The Sea of Cortez Expedition
The MonsterQuest team to the Sea of Cortez will be headed up by expert divers Scott Cassell and Dale Pearson. These are the same divers that worked on the MonsterQuest expeditions in the episodes Giant Squid Found and Giant Squid Ambush. Their plan is to use a spot plane to search for the unmistakable shark shape from the air, then attempt to rapidly intercept the shark with a boat. They will then attempt to rapidly dive in front of the shark and gather footage of the creature.
The team sets up base camp in Puertecitos, Mexico and the spot plane will fly out of San Diego, CA. They begin by examining the area around Lobos Island. This island is home to a large population of sea lions and seals, so it would be appealing to any population of large predators. The sea lions and seals seem very skittish in the area but the team can not find any large predators.
Over the next several days the spot plane is able to find what appears to be large sharks swimming in the area. The cameraman on the plane is able to capture footage of the sharks from the air but by the time the dive team arrives the sharks have dove away and disappeared.
After several days of attempts, the team receives a tip from a local fisherman that he had spotted the Black Demon in Gonzaga Bay. The spot plane is sent to the area and is able to locate a large shark from the air. The boat team is able to get to the area, locate the shark and deploy the dive team. Pearson and Cassell find a very large shark in the water but it turn out to be a 16 foot whale shark not a megalodon shark.
The HMS Challenger Tooth Study
The MonsterQuest team attempts to radiocarbon date the megalodon tooth that Dr. Tschernezky identified as being only 10,000 years old. The test is to be conducted by Dr. Tom Higham, the Deputy Director of the Radiocarbon accelerator at Oxford University. Radiocarbon dating can determine the age of organic material that is up to 60,000 years old. Modern bones should have a nitrogen percentage of around 4.5% and if the nitrogen percentage is below 0.7% they are too old and can not be dated using radiocarbon dating.
Higham obtains a sample from the HMS Challenger megalodon shark tooth for analysis. He finds the nitrogen level in the tooth to be only at 0.1% which is not enough to conduct radiocarbon dating and is a strong indication that the tooth is significantly older than the estimate by Tschernezky.
Conclusions
This MonsterQuest episode seems to show that it is very unlikely that a Megalodon shark population is still around in the Sea of Cortez. The most likely explanation for eyewitness sightings would be the misidentification of large whale sharks.
Megalodon Reference: The Monster Site
MonsterQuest Episode: Mega Jaws
Original Airdate: 18 March, 2009
Official MonsterQuest website: http://www.history.com/content/monsterquest
