Bonnethead Sharks

bonnethead shark
I am often asked if the island has sharks nearby, and like most marine ecosystems, the answer is yes. One of the most common sharks sighted from Dewees Island in summer is the bonnethead shark, Sphyrna tiburo, a member of the hammerhead family. This harmless shark is usually found in warm (over 70 degrees) shallow waters from North Carolina to Brazil.  bonnethead shark off Dewees BeachWe enjoyed watching this bonnethead shark fishing just off the beach. To feed, the shark moves it’s head in an arc, swinging back and forth like a metal detector to locate prey hiding just below or on the surface of the sand. In fact, they are able to detect electro-magnetic changes to find crabs, small fish, etc. Their large head is believed to assist in this process. They give birth to live young, and a pup is about 12 inches long when born. At 3-5 feet, they are one of the smallest hammerhead sharks. It is legal to fish for them in the surf: anglers are limited to 1 per day.

Bonnetheads can live for quite some time. In 2011, some College of Charleston students made the news by discovering the oldest known bonnethead, at 17 years. (The shark had been tagged as an adult, and recaptured twice.)

visual track of Mary Lee the Great White Shark

There are other sharks that visit our waters. A jogger found a dead blacktip shark on Sullivan’s island last week, and many people have been captivated by the travels of a great white shark in our area.  “Mary Lee” is a 16 foot great white shark tagged off Cape Cod, who travels all around the Atlantic Ocean. She is tagged with a radio transmitter that pings her location and transmits it on a map. It’s not completely exact (Mary Lee appeared, at one point, to be on land in Charleston County,) but for a broad picture of how a shark travels, it’s really neat. The Osearch Global Shark Tracker lets you follow the progress of 40 different sharks around the ocean in order to draw awareness to the valuable role sharks play as an apex predator in the ecosystem. You can even get email letting you know of the shark’s progress.

At SCDNR, there are projects in place to learn about all kinds of sharks in the estuaries.  Most of the sharks in our waters are not a danger to people, and when there are occasional bites, they appear to be a case of mistaken identity.  I am not aware of any shark bite stories from Dewees Island.  Our common bonnethead might surprise you (or your dog) by bumping into you, but they aren’t interested in you as food.  They are fun to watch from the beach or the ferry dock.  Does anyone out there have a shark story you want to share?

This Post Has One Comment

  1. Ginny Moser

    We often catvch Bonnetheads off our dock. They tend to be small at about two feet but put up a great fight. One can tell it is no red drum or other fish but it is too late to do anything about it. Very interesting critter.

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