Sharks

[denise]

Sharks are probably the best known and best recognized fish, more than 350 worldwide. They have a cartilaginous skeleton, streamlined body, a covering of denticles that gives their skin a rough, sandpaper texture, replaceable teeth (gray sharks may use over 20,000 teeth during its life!). Sharks show the most diverse range of feeding habits, habitats, size and distribution than any other fish group.

Sharks are famous for their varied and somewhat unusual senses:
· Smell: two thirds of a shark's brain is dedicated to smell, its keenest sense, some can detect as little as one part per million of blood in seawater!
· Vision: Excellent, likened to that of cats
· Hearing: Sharks can hear sounds from more than 500 feet away!
· Touch: ability to feel tiny vibrations through their lateral lines.
· An amazing ability to detect electrocurrents, through their Ampullae of Lorenzini, which detect weak electrical fields generated by prey.

Sharks rarely attack humans unless provoked. Only a few sharks are dangerous to humans, out of the 370 species, only 3 have been involved in a significant number of fatal, unprovoked attacks on humans: the great white, tiger and bull sharks. On average, there are only about 100 shark attacks each year and only 10 of those result in a human death. One is more likely to be killed by a bees or a coconut falling on their head than by a shark attack!!!

In fact, sharks have more to fear from us humans than the other way around. Humans slaughter millions of sharks per year, in the name of sport and food. Other threats to sharks include habitat alteration, damage and loss from coastal developments, pollution and the impact of our excessive fishery on their prey species.

Sharks are keystone predators, and on the top of all the worlds marine food chains. They play a pivotal role in maintaining the balance of our delicate marine ecosystems, and it is our responsibly to ensure their survival in the future. One hundred million years ago, sharks comprised 60 percent of all the ocean species; they are just three percent of the ocean's species today.

If the amazing life stories of these beautiful species doesn’t inspire us to take action to save these threatened species, consider this:
· They have strong connections to our past: They lived in the time of the dinosaurs, and have survived long past them. One shark recently found had medieval armour found in its stomach!!
· Sharks never get cancer! Their cartilage is now being used in studies with the hope of developing anti-cancer drugs.
· We kill more than 10 million sharks per year, compared to the average of 10 human fatalities caused by sharks per year! More than 75 species of shark are in danger of becoming extinct, and we are their only hope of survival.

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Nurse Shark, Ginglymostoma cirratum, Boynton Beach
Photo by Robert Palmer

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Pair of nurse sharks resting under a ledge, Lantana Beach

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Close up of a nurse shark, West Palm Beach

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Even closer..........

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Reef shark, Carcharinus perezii, CaySal Banks

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Reef Shark hunting at night, Cay Sal Banks

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Close up and underside of reef shark, Grand Bahamas

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Bull shark, Carcharinus leucas, CaySal Banks

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Blacktip shark, Carcharhinus limbatus, Grand Bahama

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Blacktip Shark, Nassau
Photo by Robert Palmer

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Blacktip Shark, Nassau
Photo by Robert Palmer