Showing posts with label shark finning. Show all posts
Showing posts with label shark finning. Show all posts

Sunday, 9 February 2014

The Disappearing Sharks









My interest in sharks was like everyone’s – morbid. A shark attack with photos was front page news and each sparked debate in the dive clubs over the best way to avoid becoming the next victim. I sometimes carried a ‘bang stick’ so I could fight these villains if it came to the worst.

When I started work on the Great Barrier Reef , I got a surprise. The sharks seemed bigger, more numerous, and very brave compared to their Caribbean brothers. Australian shark attacks were front page stories and dominated the news for days.




And yet there I was working for hours every day, year after year within metres of these predators and all I had to do to avoid trouble with the tropical species was respect their territories and not swim around with speared fish on my belt.



So how real is the case against sharks?
 Every year about 100 shark attacks are reported worldwide. In 2011,  just 17 fatalities were recorded as having being caused by sharks, out of 118 attacks.  Although shark attacks are infrequent, there is a heightened awareness due to occasional serial attacks; “it’s out there and it’s after me”. Horror fiction like Jaws appears on TV just often enough to keep this fear alive and even “nature” shows only show sharks in frenzied feeding.



Shark attack experts are adamant that the danger has been greatly exaggerated. According to the International Shark Attack File (ISAF), between the years 1580 and 2011 there were 2,463 confirmed unprovoked shark attacks around the world, of which 471 were fatal. Surprisingly, that’s only 1.09 fatalities per year for the last 431 years.
Australia is ranked second in terms of global shark attacks with 877 attacks since colonial settlement in the 18th century; it’s ranked the highest in terms of shark fatalities, with only 217 during this long period.
The results of Gore’s Michigan State University study reviewing worldwide media coverage of sharks found that more than 52 percent of global coverage focused on attacks on people and sharks were portrayed as aggressive and dangerous in nearly 60 percent of the reports. Positive PR was tougher to find with only 10 percent of stories dealing with shark conservation and just 7 percent looking at biology and ecology.
According to Time/ CNN : Zoologists today estimate elephants around the world kill 500 people a year while the great white sharks (Jaws)  kill only 4 people.

Incredibly, there are about 24,000 lightning deaths (one every 20 minutes) and 240,000 injuries worldwide annually (Royal Aeronautical Society, 2003). When was the last time we read stories of the lurking danger above or watched a movie where people were struck down like dominoes by searing thunder bolts?

Why is shark conservation so important and why is it being neglected?

The first part of this question is easy. Sharks are in big trouble. "Overfishing of sharks is now recognized as a major global conservation concern, with increasing numbers of shark species added to the International Union for the Conservation of Nature's list of threatened species," say Mizue Hisano, Professor Sean Connolly and Dr William Robbins from the ARC Centre of Excellence for Coral Reef Studies and James Cook University.
 Why we are neglecting shark conservation is harder to answer. First, there have been powerful economic reasons to turn a blind eye to shark fishing and shark finning. These may not have been good reasons but greed is a characteristic of human behaviour and we make lots of poor decisions because of it.





A second explanation comes from deep in the primitive part of our brains. Our prehistoric ancestors had the very same fears that we do according to Psychology Today. We were ‘designed’ to be afraid; fear was our operating manual for things we didn’t understand or that could do us harm. Fears protected our ancestors. “Our distant ancestors who were afraid of heights didn’t fall off cliffs, those that feared wild animals didn’t get eaten, those that ran the fastest left the rest behind---and they survived.” 

 Elephants are not on our list of feared animals and we donate millions of dollars each year to protect them even though they kill thirty times more people than sharks. Why can’t we see that the health of our ocean hangs in the balance and that we are making decisions with our ancestor’s fears and not with our future in mind?

Special thanks to my friends Ellen Cuylaerts and Shawn Heinrichs whose photos 'tell' the story.







Friday, 6 December 2013

Whale Sharks in the Andaman Sea









The largest living fish species is the whale shark, Rhincodon typus. Whale sharks grow up to 12.2 m and can weigh up to 13.6 tonnes. The species is believed to have first appeared about 60 million years ago and is now the last surviving species of this group of giant sharks.



The shark is found in tropical and subtropical temperatures mostly in the open sea. It will enter lagoons and coral atolls, bays, and rarely estuaries if the water is rich with plankton (microscopic marine plants and animals). It is migratory and probably returns to the same areas to feed each year.

 
 Whale sharks grow up to 12.2 m and can weigh up to 13.6 tonnes

Little is known about this ocean giant. Scientists believe that they live for about 70-100+ years. The whale shark is generally solitary. They reach sexual maturity at around 30 years, when the female can become pregnant with up to 300 pups. These are born alive after the eggs hatch inside her (they are ovoviviparous). The pups are about 40-60 centimetres long at birth.

 
The whale shark is no threat to the diver


Although whale sharks have very large mouths, they feed solely on plankton and other small animals by filter feeding. To catch their meal they pass water through their five pairs of gills which are covered in fine, bristle-like structures that strain and hold the food (anything above 2 to 3 mm in diameter is trapped). Studies show that their diet consists of plankton and larger algae, zooplankton, krill and slow swimming animals like small squid and juvenile fish.


 


About 60 million years ago whale shark evolution solved the problem of finding enough dolphins and small whales to eat. They switched their diet to the tons of plankton that could not escape their huge mouths (which can be up to 1.5 metres wide). Evidence of their once predatory nature is still provided by 300 -350 rows of tiny teeth. These teeth are no longer used in feeding and have become very small in size.



When feeding in low concentrations of plankton, the whale shark simply cruises along at an average speed of about 5 km per hour with its mouth open. When it encounters schools of krill or small fish it slows and begins gulping and filtering water at hundreds of liters per minute.

 
 Many thanks to my friend Ellen for this great whale shark feeding photo


Two small eyes are located towards the front of their head and their vision is probably poor. A whale shark’s 10 centimeter thick skin protects them from the bite of smaller sharks. It is believed that adults have few predators.



The largest specimen recorded was caught near Karachi, Pakistan. It was 12.65 metres long, weighed more than 21.5 tonnes, and had a girth of 7 metres. There are stories of much larger specimens (quoted lengths of 18 metres) in the popular shark literature but no scientific records support their existence.


 

These gentle giants are not a danger to humans. They are actually quite gentle and will play with divers. Divers and snorkelers can swim with whale sharks without risk other than being struck by the shark's large tail as it swims past.

Sadly, these wonderful animals, the largest fish in the sea, are killed just for their fins. The fins are used to make soup for fancy dinners.




Check out some other really cool creatures in some of the other posts on this blog site.