Lemon Shark in black and white

Sharks

Great Hammerhead Sharks of South Bimini

Like a fashion model up on the catwalk, great hammerhead sharks sashay into one’s field of vision, and, if they were human, you would probably say they have just “made an entrance”. Their strange mallet-like head, robust body girth and tall sickle-shaped dorsal fin make them well-nigh instantly recognisable, and most other sharks in the immediate area spot that too and give them a wide berth.

Removal of large shark species by fishers may lead to explosions in smaller shark species

Sharks influence fish communities at coral reefs

The research team from University of Western Australia arrived at this conclusion after a study involving two coral reefs. At one of the reefs (Scott Reef), shark hunters had been legally permitted to hunt sharks while the other reef (Rowley Shoals) was situated in a marine protected area.

Sand Tiger Shark. Evidence of complex social behaviors in sharks and other elasmobranchs is sparse, however we are beginning to understand the importance of studying shark aggregations

Sand tiger sharks have a friendly side

While many sharks are solitary predators, some are known to live in groups and are suspected of engaging in complex social behaviors. Meanwhile others simply aggregate due to similar habitat, food, or mating requirements.

Using a novel tagging procedure, scientists in the United States, have discovered that some shark species like to spend their time mixing and chilling out together.

Tom Haight's portrait of a megamouth shark
The sixth megamouth shark, found off California

The Mysterious Megamouth Shark

It was not until eight years later, in November, 1984, that another one was found, in a deep-sea net off California. It too, was a male 4.5 metres in length. The third, also male, was a metre longer, and washed up on the shore of Australia, on August 18, 1988. In the following years, megamouth sharks appeared more frequently in a variety of places around the globe.

Tiger shark dance
Enjoying the 'Shark ballet'

The Value of Shark Dives

So shark dive clubs usually bring some fishy scraps—in most cases the remains left over after big fish have been cut up for sale. The scent attracts the sharks into view and provides a bit of excitement as the animals investigate and try to get a piece. But little actual food or nourishment is given. The sharks circle far and wide through the vast volume of the visible ocean, in a memorable and dramatic display, as they look over the scene, zoom in for a closer look, try for a scrap, and socialize.

Hammerhead, Bahamas
Hammerhead, Bahamas. The great hammerhead—considered endangered by the IUCN Red List—is the largest of the nine hammerhead shark species

Large sharks benefit from marine reserves

Current research has shown that waters off Florida and the Bahamas are important pupping and feeding grounds for several sharks, providing them with the critical habitat required for the conservation of these slow-to-mature ocean animals.

Researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science studied the core home range of 86 bull, great hammerhead and tiger sharks tagged in waters off south Florida and the northern Bahamas.

Great White Shark
Great White Shark

Stewart Island shark cage diving creates controversy

A New Zealand parliamentary select committee has raised concerns about the potential human risk from shark cage diving around Stewart Island. The Local Government and Environment Committee published a report considering a petition calling for the Department of Conservation (DOC) to immediately and permanently cease shark diving. The petition was created by Stewart Island resident Helen Cave and signed by 768 people.

Although Bull sharks have been implicated in many attacks on bathers, divers are normally not harassed unless they are spear fishing.

Divers cautioned about disturbing breeding bull sharks

Bull shark diving is becoming a popular tourist activity in the waters around Cancun, Playa del Carmen and Cozumel.

Be quiet

Luis Lombardo Cifuentes, director of Saving Our Sharks, told the Riviera Maya News they have noticed the sharks displaying fearful behaviour this year and are asking divers to use extreme caution when approaching them by being very quiet and not make noise in the water.