'Most Wanted Sharks': Meet Deep Blue who could be the largest and oldest living great white shark
National Geographic's Sharkfest programming may be an eye-opener for many viewers who get to learn about some of the most terrifying predators in the ocean much more. The latest special, 'Most Wanted Sharks' focuses on some of the most famous sharks in the ocean, including Patches, a hammerhead shark, and Zapata, a great white shark. One of the sharks of great interest that was featured on the program is Deep Blue, touted as one of the oldest and largest living sharks.
Deep Blue measures 20 feet from tip to tail -- most female Great White sharks usually measure 15-16 feet when they are fully grown -- and it is estimated that she is still growing. She is also estimated to be at least 50 years old. Great White sharks are generally elusive creatures -- while they are terrifying, there is not a lot that researchers know about the species. The species is also listed as vulnerable by the International Union for Conservation of Nature (IUCN) and is featured on the organization's Red List. The Great White sharks face many threats, including sport fishing and accidental killing as bycatch.
Deep Blue's reputation as the “biggest” shark on record can be attributed to Discovery Channel's 2014 'Shark Week' episode (shot in 2013) in which Mauricio Hoyos Padilla, director of the shark nonprofit Pelagios-Kakunjá, and others filmed the large female near Mexico’s Guadalupe Island. In 2015, Padilla wrote on Facebook that she was “the biggest white shark ever seen in front of the cages in Guadalupe Island,” which somehow became “the largest great white shark ever caught on film.”
One of the most amazing facts about Deep Blue is that multiple times when she was spotted, she has been pregnant. Great white sharks are elusive when it comes to mating and reproduction, so having the most famous living shark commonly be spotted pregnant gives the world an amazing glimpse into this little known part of their lives.
Great whites don’t reach sexual maturity until very late in life, estimated to be around 26 years for males and 33 years for females by Woods Hole Oceanographic Institution. Great white sharks are ovoviviparous, which is a fancy term for saying they grow and lay eggs inside the mother, who then keeps the living young in the womb during gestation. Females have an eleven-month gestation period before giving birth in spring and summer.
This long gestation period means females usually breed every other year, sometimes even skipping years depending on various factors such as scarce food or availability of mates. The whole reproduction cycle is extremely slow, starting from the great whites taking so long to reach sexual maturity to long gestation periods and infrequent mating. This all causes great white sharks to be extremely vulnerable to population drops due to hunting, scarce food from overfishing, and unsuccessful pregnancies or health problems caused by bioamplification.
'Most Wanted Sharks' first airs on Thursday, July 23, at 10/9c on National Geographic. An encore presentation will follow on Tuesday, August 11, at 7/6c on Nat Geo WILD.