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The Great White Shark (Carcharodon Carcharias) is the largest predatory fish in the world. While they are found in all oceans and seas, they tend to prefer coastal temperate waters. There is very little known about the Great Whites migration pattern, but thanks to tagging, more is being learned every year. In one study, the female Great Whites migration pattern is studied, and in another the lipid filled liver of the Great White proves to be a great energy source for their long trek. The movie ‘Jaws’ gave Great Whites a horrible reputation. However, they are not quite the man-eaters they have been made out to be. Most shark attacks could be avoided by being more aware of your surrounds. Great Whites in captivity, while being extremely helpful for research, study and overall awareness of these great creatures, could have some adverse side effects to the animal.

Abstract

Introduction

So little is actually known about the migratory pattern of the Great White Shark, but in recent years tagging has become much more popular and has revealed a lot more about their journey. In an article on the Animal Biotelemetry website, a two year study by Michael Domeier and Nicole Nasby-Lucas about the two-year migration of adult female Great White Sharks is reported. The study was released in 2013 and has revealed a great deal about the long journey the female Great White Shark makes. The sharks were tagged with satellite tags off the coast of Guadalupe Island. The tags aloud the researchers to track the sharks on their long migratory journey. After becoming pregnant, the female Great Whites would swim great distances out into the open ocean. This journey, according to the study, lasted roughly fifteen and a-half months. The sharks would then return to the coast at Baja, California where they gave birth a few months later (Radford, 2013). One huge point this study was able to prove, was that Guadalupe Island serves as a mating site for adult white sharks and is visited every year by males and every two years by females (Domeirer and Nasby-Lucas, 2013). It also provided further proof that the white sharks gestational period is in fact 18 months. It proved this because the study showed the female Great Whites out in the open ocean for roughly sixteen months and giving birth two months after returning to the coast at Baja, California.

This image was taken directly from the published study. It shows Four female Great Whites that were tagged off the coast of Guadalupe Island. They make their journey out into the open ocean, and then back to the coast of Baja California to give birth. The white circle represents the male White Sharks presence every year, right around the island. Source: http://www.animalbiotelemetry.com/content/1/1/2

Another study conducted by Susan Milius proved just how important the Great Whites oily, lipid filled liver is to its migration from California to Hawaii. Great Whites in the Eastern Pacific make this migration during springtime and travel back in late summer. The almost 2500 mile journey to Hawaii takes one month to complete. Those Great Whites need a lot of energy to complete a trek like that. Using a combination of different tags, Great Whites traveling to Hawaii showed their buoyancy decreasing as they got closer and closer to their destination (Milius, 2013). The oily liver in Cartilaginous fish is like the swim bladder in bony fish. In bony fish, the swim bladder is a gas filled structure that keeps the fish from sinking. In the shark, its main purpose is to help keep the shark afloat with all of the lipids stored in it. The fact that the shark’s buoyancy is decreasing shows that those lipids are being used as energy to get the shark to its destination. This data provides researchers with the first piece of evidence that proves the great white uses stored lipids in the liver as an energy source during migration (Milius, 2013). Not only does it help them float, but it also provides them with a great energy source for long journeys.

Migration The release of the infamous movie ‘Jaws’ in 1975 depicted The Great White Shark as a ruthless killing machine, eating everything in its path. However, looking strictly at the facts, this just doesn’t seem like an accurate depiction. According to the International Shark Attack File, between 2000 and 2010, of the 700 reported shark attacks, 66 were from Great Whites and only 14 were fatal (Civard-Racinais, 2012). The Great White doesn’t have hands like humans do, so they must use something else to test out new things they come across. Their mouth and taste buds are the most readily available, so they take a test bit to identity new objects that attract them (Civard-Racinais, 2012). This is probably why The Great White tends to bite and then release their victim, not liking what it has just tasted. Also, most shark attacks occur because people are unaware of sharks in the area and could unknowingly be entering their territory, threatening them and provoking an attack. In a piece written by Frederic Buyle, an underwater photographer and free-diving world champ, Buyle talks about the Great White and how he doesn’t believe them to be anymore dangerous then other sharks in the ocean (Civard-Racinais, 2012). Most of what he discuses is how when diving with Great Whites, or any shark for that matter, it is important to realize that this is their environment and be very respectful of them and their space.

Relationship With Humans

References: Civard-Racinais, A. (2012). Great White Shark: Myth and Reality. Buffalo: Firefly Books Ltd.

Lineback, N., & Gritzner, M. (2013, February). Geography in the News: The Great White Shark’s Habitats. Retrieved from http://newswatch.nationalgeographic.com/2013/02/03/geography-in-the-news-the-great-white-sharks-habitats/

Radford, E. (2003, April). Great White Shark Migration And Mating Secrets Revealed. Retrieved from http://www.inquisitr.com/603732/great-white-shark-migration-and-mating-secrets-revealed/

Monterey Bay Aquarium (2013). Saving Great White Sharks. Retrieved from http://www.montereybayaquarium.org/cr/whiteshark.aspx

Domeier, M., & Nasby-Lucas, N. (2013). Two-Year Migration of Adult Female White Sharks (Carcharodon carcharias) Reveals Widely Separated Nursery Areas and Conservation Concerns. Animal Biotelemetry, 1(2), full text. doi: 10.1186?2050-3385-1-2

Milius, S. (2013, Aug 10). Liver fuels white shark migration. Science News, 184, 12. Retrieved from Proquest database (1420185032)

Huffington Post. (2011, November). Monterey Bay Aquarium’s Great White Shark Dies A Week After Release. Retrieved from http://www.huffingtonpost.com/2011/11/05/monterey-bay-aquarium-great-white_n_1076187.html

Carcharodon carcharias, or The Great White Shark as it is more commonly known, is a cartilaginous fish that is considered to be the largest predatory fish in the world. They can grow up to twenty feet long and can reach speeds of thirty miles an hour. They can be found in all oceans and seas in the world, though they are more common in coastal, temperate waters. Great Whites are very much solitary animals, but are known to travel and live in groups on occasion. While Great Whites are known for their attacks on humans, we are not typically on their menu. Their main source of food comes from the order of Pinnipedia that includes seals, sea otters, and sea lions. They are also known to occasionally feed on bony fish, sea birds, dolphins and sometimes other sharks. The Great Whites tendency to eat large prey has forced them to develop large, serrated, triangular teeth to saw chunks out of their large prey. The Great White reproduces ovoviviparously. This means the egg develops inside the mother with a large yolk that nourishes the babies. The egg then hatches inside the mother just before she gives birth to the live young.

By: Alexa Erickson The Great White Shark

Distribution/Habitat The Great White Shark is present in all oceans and seas of the world, and while they do tend to prefer temperate and subtropical waters, they are known to visit more tropical waters as well (Civard-Racinais, 2012). They are most common in the upper portion of the ocean, between 0 and 820 feet. They aren’t permanently found out in the open ocean, but do spend some time there when making migrations or, for females, when they become pregnant and return to coastal waters just before giving birth. They are most commonly found off the coast of North America, Australia, Japan, and Chile to name a few (Lineback and Gritzner, 2013). One of the largest known Great White populations is around Dryer Island, South Africa. This fact makes this area the prime place for research to take place (Lineback and Gritzner, 2013).

This image shows, in purple, the areas where the Great Whites live. Source: http://newswatch.nationalgeographic.com/2013/02/03/geography-in-the-news-the-great-white-sharks-habitats/

In Captivity The Monterey Bay Aquarium in Monterey California started a program in 2002 called Project White Shark. The goal of this project was to promote the study, awareness and conservation of the Great White Shark (Monterey, 2013). They have held in captivity 6 juvenile Great Whites between 2004 and 2011. Each time, they draw in huge numbers of people, all eager to see and learn about these powerful creatures. All six stayed on exhibit for different amounts of time, but all of them went back into California coastal waters with tags to track them and learn even more. While this new method seems to be working well for scientists who want to study and learn more about these creatures, what about the animal itself? In 2011, The Monterey Bay Aquarium released their latest Great White back into the wild, where it died shortly after (Huffington Post, 2011). Being captured and placed in a large tank for a few months must be very stressful for this animal, never having been in captivity before. The concept is great, pulling in lots of people to see and learn more about this animal, but there seems to be some flaws that need to be address before the aquarium brings in another Great White.

A solitary Great White Shark swimming in the open ocean. Source: http://www.bbc.co.uk/nature/life/Great_white_shark Photo taken by Doung Perrine

The official poster for the film ‘Jaws’. Source: http://www.scubadiving.com/article/news/celebrating-film-jaws

The dissected underbelly of a Great White. This image shows just how large the liver is, as it was pulled out of the fish and laid out. Source: http://www.digitalfishlibrary.org/featured/great_white/slideshow.html

This image shows one of the six juvenile Great Whites that the Monterey Bay Aquarium has held in captivity. Source: Monterey Bay Aquarium website.