Creature Feature: Great White Shark

Great White Elias Levy

Photo by: Elisa Levy

Da, Da! Da, Da! Da,Da,Da,Da,Da… This week’s shark is probably one of the most famous. The Great White Shark (Carcharodon carcharias) is the largest predatory shark, reaching a length of 20ft (or more) and weighing 5000lbs (or more). Now, this shark is a lot scarier in our minds than in real life. The thought that this shark is a man-eater stemmed from fears that were fueled by movies. Nowadays this thought is slowly dissipating.

Shark mouths are full of sensory organs, they take “exploratory bites” to test potential food items, and will abandon objects that are not suitable food.  Let’s think about how we look in the water: especially on surf boards, we swim splash and move like their food, seals and sea lions. Once they get a taste of us, plus the plastic and neoprene of our gear, generally the sharks will let go and swim away.

Great white Travelbag Ltd

Photo by: Travelbag Ltd

Great White Sharks are ambush predators that hunt in temperate waters around. They utilize counter-shading to blend into their surroundings and surprise their prey. They have a dark grey upper body (dorsal side) to camouflage to the depths when viewed from above, and a white underside (ventral side) that looks like the surface of the water viewed from below. Locally, you can find an amazing feeding ground located at the Farallones National Wildlife Refuge, just 30 miles west of the Golden Gate Bridge. This is an amazing protected habitat, where limited numbers of people have the opportunity to view and study Great White Sharks. Researchers are able to identify white sharks by their scars and with satellite relay tags. These tags have helped to see the migration patterns of these individuals going from the Farallones to Hawaii to Southern California, and back to the Farallones.

Like many sharks, human pressures on the population makes them vulnerable. For years, the white shark was killed and hunted because of the “Man-eater” label and increased after media influence. Jaws and teeth are considered highly valuable, and trade throughout the world has led to a decrease in population. However, sharks have another value; they play an important ecological role. Studies have shown that if even a couple of white sharks are extracted from the habitat it could have an influence on the health of the ecosystem, including a cascade throughout the food chain. For example, white sharks keep the population of seals and sea lions in check. Because of their important role, and to protect their numbers from further diminishing, this species is protected in certain waters throughout the world including the US.

Sharks are magnificent creatures that share our waters. Check out next week’s creature feature–the number one most “dangerous” shark. Do you know what it is? Write your answer below.

References:
Edited by KC O’Shea
Photography: Elisa Levy and Travelbag Ltd
http://animals.nationalgeographic.com/animals/fish/great-white-shark/
http://www.enchantedlearning.com/subjects/sharks/species/Greatwhite.shtml
http://www.ucmp.berkeley.edu/vertebrates/Doug/shark.htmlhttp://www.fws.gov/refuge/Farallon/about.html
http://www.iucnredlist.org/details/3855/0

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