SHARKS: feared or revered, but rarely understood.

The creators of “Jaws” had it backwards. People prey on sharks far more than sharks prey on people.

For some, sharks are the stuff of nightmares. Others rely on them for a living – and humankind has driven many species into decline. Perhaps it is time to think again about how we treat these beautiful creatures.

Shark fins have no taste and no nutritional value, but they’re nonetheless a hot commodity in Asia. People consider shark fin soup a high-status, luxury dish, and their demand for the soup fuels the decline of shark populations around the world.

To feed that craving, fishing fleets capture millions of sharks each year, cut off their fins, and in many cases, toss the dying animals back out to sea to make more cargo space on board for the fins. Slow to mature, sharks are often killed before they have a chance to reproduce.

As a result, 20 percent of all sharks and their closest relatives are threatened with extinction, according to the most recent IUCN Red List of Threatened Species.

The shark fin trade is perhaps three to four times larger than previously estimated by the United Nations Food and Agriculture Organisation (FAO), the main monitoring database for the world’s fisheries. According to a paper published in the October 2006 edition of Ecology Letters, co-authored by the Pew Institute for Ocean Science, an estimated 26 million to 73 million sharks are killed each year for their fins.

“Wholesale removal of top predators from ecosystems will very likely bring unexpected and undesirable problems,” says Scott Henderson, Conservation International’s (CI) coordinator for the Eastern Tropical Pacific Marine Program.

Protecting sharks requires extensive collaboration among scientists and governments around the world.

Things You Didn’t Know Sharks Do For You

In reality, you are more likely to be killed by your toaster than a shark … and if sharks were to disappear, it would be bad news for all of us. Here are just a few of the reasons why.

Sharks keep the food web in check.

Many shark species are apex predators, meaning they reside at the top of the food web. These sharks keep populations of the species they prey on in check, weeding out the weak and sick animals to keep the overall population healthy. Their disappearance can set off a chain reaction throughout the ocean — and even impact people on shore.

For example, a study found that large sharks have declined dramatically in the northwest Atlantic since the mid-1980s. The presence of fewer sharks led to a population explosion of species like cow nose rays, which in turn depleted the region’s bay scallops. This was an important factor in the collapse of North Carolina’s century-old bay scallop fishing industry.

Sharks could hold cures for diseases.

It has puzzled researchers for years: Why don’t sharks get sick? (They do, of course, but not as often as other species.) Shark tissue appears to have anticoagulant and antibacterial properties. Scientists are studying it in hopes of finding treatments for a number of medical conditions, including viruses, cystic fibrosis and some forms of cancer.

Sharks help keep the carbon cycle in motion.

Carbon is a critical element in the cycle of life; as you might remember from high school biology class, all living things contain carbon.

By feeding on dead matter that collects on the seafloor, scavengers like deep-sea sharks, hagfish and starfish not only keep themselves alive, they also help to move carbon through the ocean.

In addition, research has found that, like trees, large marine animals such as whales and sharks sequester and store large amounts of carbon in their bodies. When they die naturally, they sink to the seafloor where they are eaten by scavengers, as mentioned above. However, when they are hunted by humans, they are removed from the ocean, disrupting the carbon cycle.

Sharks aren’t just tough on the outside—a substance in their bodies can stop viruses in their tracks, a new study says. Christine Dell’Amore

Sharks boost local economies.

Over the last several decades, public fascination with sharks has developed into a thriving ecotourism industry in places such as the Bahamas, South Africa and the Galápagos.

According to a study recently published in the journal Oryx, shark tourism generates about US$ 314 million per year and is predicted to more than double in the next 20 years. These activities — which support businesses like boat rental and diving companies — are said to provide 10,000 jobs in 29 countries. Several studies have indicated that in these places, sharks are worth much more alive than dead.

In addition to these benefits for people, it’s likely that sharks fulfill other roles in their habitats that we have yet to understand or appreciate.

Species are sometimes called the “building blocks of ecosystems,” Yet humans continue to remove these blocks without fully understanding the consequences. Up to 100 million sharks are currently killed every year, largely for the shark fin trade.

Think of the world’s biodiversity as a giant game of Jenga: if you keep removing blocks, eventually the whole thing will come tumbling down. Say: Molly Bergen.

Why Do Sharks Attack?

Sharks attack and kill 10 humans per year, on average. Humans, in contrast, annually kill about 20 to 30 million sharks, according to the Florida Museum of Natural History’s Department of Ichthyology. That shark death estimate, based on commercial and sport fishing landings, could even be conservative. It is therefore not too difficult to see which species poses the greater threat to the other. After 400 million years of shark evolution, we could potentially wipe out the world’s sharks in a century’s time.

The fact remains, however, that sharks can, and do, result in human deaths. Dogs and even traditionally mild-mannered animals like cows may kill people too, but the nature of shark attacks seems to fascinate and terrify us more. This year alone, two surfers from Mexico and two from California lost their lives after bleeding to death due to shark bites. The cluster of deaths puzzles researchers because, as shark numbers are declining overall, attacks seem to be holding steady, or are even rising, depending on the region.

How Sharks Attack People.

According to author Murray Suid and George Burgess, a senior biologist and director of the International Shark Attack File, there are four basic types of shark attacks on humans. The first and, by far, the most common are provoked attacks. These occur when people in some way touch, or otherwise disturb, sharks. Fishermen removing sharks from their nets, for example, might lose a finger or limb if not careful. Sometimes divers have taunted or tried to grab a shark, with not-surprising consequences.

Unprovoked attacks can happen in three principal ways. The most frequent of this type are hit-and-run attacks — when the shark grabs, releases and leaves the scene. The shark could be investigating the individual, thinking he or she was its usual prey. It might also perceive the individual as a threat, similar to how a more aggressive, yet fearful, dog could attack anyone who mistakenly treads on its turf. The two other types of unprovoked attacks are sneak attacks, when a deep-sea shark moves upon a diver unawares; and, finally, bump-and-bite attacks, when a shark head-butts a person before it takes a bite.

Ways of Preventing Shark Attacks

The NOAA Fisheries Service offers the following tips on minimizing the risk of shark attack:

  1. Stay in groups and do not wander away from your companions, since sharks are more likely to attack individuals.
  2. Avoid being in the water during early morning and late afternoon, since sharks actively feed at those times.
  3. Never go into the water if you are bleeding, even if the cut or injury is minor. Sharks possess very keen senses, and blood could attract one from several feet away.
  4. Don’t wear shiny jewelry when in the water. The glisten mimics fish-scale sheen and visually labels you as shark prey.
  5. Stay away from sport or commercial fishermen when in the water, as their catches could attract sharks.
  6. Avoid wearing brightly colored clothing in murky waters, since sharks easily perceive color contrasts.
  7. Refrain from excessive splashing, which could mimic the movements of injured or disoriented prey fish and animals.
  8. Sandbars, steep drop-offs and estuary inlets tend to be shark hangouts, so avoid swimming in these places.

While fear of sharks is well founded, the greater fear should be of shark extinctions, since no one really knows what could happen to ocean ecosystems without the managing presence of these elasmobranches. Since everything from total ocean system collapse to food shortages for humans, due to diminished fish catches, has been theorized, hopefully such fear can fuel conservation action before any of these unthinkable scenarios come to pass.

We at GreenDustries work for our Environment.

 

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