Great Dog is just one island in the BVI that boasts an amazing dive site called The Chimney. The teen divers on one of our June adventures began exploring The Chimney with a trip through a winding underwater channel blanketed with living sponges and rainbow coral. Sun shined through the chamber from above to reveal a spectacular hammerhead shark!
We usually see nurse sharks in the BVI, and like the nurse sharks, most hammerhead species are considered harmless to humans and they are generally rather small in size. They live twenty to thirty years in the wild. The most interesting anatomical feature is their crazy-looking mallet-shaped head. That head certainly has its advantages, improving the shark’s ability to find prey. First, the distance between its widely spaced eyes makes for a range of vision that exceeds the range that most other sharks have. It’s incredible to think that this shark can see 360 degrees in a vertical plane, meaning everything above and below simultaneously.
This shark is a carnivore and its wide head is packed full of extremely specialized sensory organs that do a great job of scanning for food on the ocean floor. Some of these sensory organs are so sensitive that they can actually detect the electrical fields generated by prey. That is a huge help when it comes to sweeping the sandy bottom for food. They enjoy eating a variety of fish, squid, octopus, crustaceans, and other sharks, but their favorite meal is a stingray. Catching a stingray is also accomplished using the hammerhead. The shark pins its prey against the ocean floor until it tires, weakens, or goes into shock. At that point, it’s an easy meal!
Approximately 100 million sharks are killed each year in commercial fisheries. It’s likely that more than half of all sharks and shark-like species are threatened or near-threatened with extinction. Many threatened or near-threatened shark species, including the oceanic, whitetip, scalloped hammerhead, tiger, and Caribbean reef sharks, swim in the waters off the British Virgin Islands. In 2014, the BVI Government took action and established a permanent shark sanctuary throughout its waters prohibiting commercial fishing of all shark and rays species and banning the sale and trade of sharks and shark products.