Thursday, 02 June 2016 11:22

Great White Shark Sightings

Winter in the Southern Hemisphere is known as the best season to view Great White Sharks. Here in Gansbaai, we have sharks all-year-round, but Winter is still traditionally considered as the best season. There are a few contributing factors, such as the fact that there are more sharks hanging around Shark Alley during Winter, the water visibility improves and the water temperature is a few degrees warmer than in Summer. Thanks to the Great White Shark’s rete mirabile, they are able to raise their body temperature about 10’C warmer than that of the surrounding water, which in layman’s terms relates to the sharks being a little lazy when the water is cold and when the water is warmer, they feel a little friskier. The big males make their appearance in winter, just in time for the Cape Fur Seal pups to take their first plunge into the Atlantic and test their aquatic skills. Generally, we see more females than males during Summer and more adult males during Winter.

Published in Latest News
Tuesday, 19 April 2016 07:55

8 Facts about the vision of Sharks

1. Effective up to 25 meters

2. 10 times greater than humans in clear water

3. Eyes very similar to humans – cornea , lens, retina, iris, pupil

4. Contains rods and cones so can detect colour and see in low light – new research (2011) shows not all sharks have the same cones cells, bull sharks cannot see in colour.

5. Tapetum lucidum – detects very small amounts of light which is why they can see in very murky water

6. Can see out of the water as well – pupil dilation

7. Iris is a vivid blue colour

8. Nictitating membrane (eye lid) lacking in great whites so they roll their eye back for protection

Published in Latest News
Wednesday, 11 February 2015 08:26

I’m FINished with FINS

Love, that curious, chemically charged emotion which we feel towards our favourites, will be celebrated again on Valentine’s Day, this coming Saturday. (And yes, it is my pleasure to have reminded you . . .) If you are reading this, then there is no doubt in my mind that you are a shark lover! And so why not combine the two? Valentine’s Day with Sharks as the emphasis? How preposterous, right?! Shark lovers will probably find this idea adorable but really, what’s the relationship between sharks and couples? 

Well, we all know that shark fin soup is usually a must-have core dish served at Chinese weddings. The team from wedding.com.my aims to raise awareness under their platform to encourage their fans to not feature shark fin soup at wedding banquets. Co-founder of Wedding.com.my, Petrina Goh, told Vulcan Post said that “The whole idea came about when we were thinking… What will be a better way for couples to celebrate their love while doing a good cause at the same time?”

In March 2014, Shark Savers Malaysia (SSMY) was launched and powered by Malaysian volunteers with the support of corporate pro bono resources and local NGO partners. The Malaysian government instituted a ban on shark fin soup at all official state level dining and entertainment in October 2014. 

The wedding.com.my team planned a 3-part event for Valentine’s Day – the main event being the Shark Savers Couple Challenge where they aim to raise public awareness and hand out pledges which says “I’m FINished with FINS”. As an online wedding marketplace, they feel that they have a strong social responsibility to bring awareness to their 200,000 bridal community, since shark fin soup is mostly consumed at wedding banquets.

According to the latest reports, Malaysia is globally ranked 8th for shark catchment and 4th for shark fin imports. Hopefully the efforts of wedding.com.my and Shark Savers will filter through the Malaysian population and help to reduce the above mentioned statistics. 

Conversely, what will you and I be doing to show our love for sharks this Valentine’s Day?

Well, let’s look at what we can do:

  • Take your loved one for a walk on the beach, clean up some debris and then enjoy a lovely romantic picnic on the beach at sunset.
  • Buy your lover a t-shirt or jewellery from a shark conservation organisation.
  • Adopt a shark as a gift for your Valentine!
  • Donate funds to a shark NGO on behalf of your Sweetheart.
  • Spend a day volunteering together at a shark organisation.
  • And on Valentine’s Day, as with every other day of the year, be the best Shark Ambassador you can be! Say no to shark products!

 Wishing you all a very Happy Valentine’s Day!

Published in Latest News
Thursday, 19 February 2015 07:41

Remains of a 15-million-year-old shark found

And in other shark related news;

Donald Gibson found the first vertebra just as he had begun to dig out the space for the sunroom he had promised to build in the back yard of his parents' home in Calvert County, Maryland, USA.Over the following week more and more vertebrae were found — each one about 18 inches deep into the groundBut then they found a straight column of vertebrae, two feet long as well as a tooth.

The digging stopped.

What the Gibsons unearthed were the remains of a 15-million-year-old Snaggletooth shark found, which palaeontologists say is more complete than any other fossil of its kind in the world.

The Gibsons' discovery is so unusual because of the number of bones they found — more than 80 vertebrae and hundreds of teeth, all from the same shark — as well as the position they were in and their unusually good preservation.

Palaeontologists Godfrey and Nance were called to the scene and they were amazed at the find. They immediately wrapped the entire skull cavity in a stiff plaster cast, like one used to set a broken bone.

Sharks' skulls are made mostly of cartilage, not bone, so they almost never withstand the ravages of time. Yet somehow, the shark that came to rest in the Gibsons' backyard sank belly-up when it died during the Miocene Epoch. It became buried in sand, then by sediment eroding from the Appalachian Mountains. And its skull cavity — containing hundreds of the distinctively shaped teeth, up to an inch-and-a-half long, that give the snaggletooth its name — kept its shape.

Using a microscope, the scientists digging in the Gibsons' yard were able to see the distinctive hexagonal shape of shark cartilage, fossilized and preserved.

Godfrey said that this shark was 8 to 10 feet long during its life.

Having preserved the teeth and surrounding remnants of cartilage in exactly the positions they were found in, the palaeontologists will be able to take CT scans of the cast and analyze the specific three-dimensional layout of the prehistoric shark's mouth, something scientists have never done.

"For the first time, we're going to be able to know what the dentition — what the teeth — looked like in this kind of shark," Godfrey said.Then they will remove the cast, gently clean each piece and put the discovery on exhibit.

Godfrey said he is receiving emails from palaeontologists up and down the East Coast who are excited about the discovery.The skeleton will allow scientists to compare the prehistoric snaggletooth, an extinct species, and modern snaggletooths, a descendant species that lives in the Pacific.

Comparing the teeth of snaggletooths then and now will help scientists understand the workings of shark evolution, the likely diet of prehistoric species and the climate during the Miocene Epoch.

And the fact that the spine and the skull cavity of the shark found by the Gibsons are definitively associated with each other, the most complete snaggletooth skeleton ever found will allow scientists to identify whether smaller pieces of future fossils come from snaggletooths or other species.

"When in the future we find just a single vertebra, we'll be able to say, 'This comes from that kind of shark.' And only because we have this association being made," Godfrey said. "It's just incredibly unlikely that we would make this kind of discovery."

Published in Latest News
Thursday, 12 March 2015 08:12

White Shark Projects

Published in Latest News
Wednesday, 27 May 2015 08:50

Great White Shark Pups

Very little is known about the location of mating and pupping of Great White Sharks. A Great White Shark birth (and mating) has yet to be photographed/filmed/or otherwise documented anywhere in the world!  They are ovoviviparous, give birth to 2-14 live pups, and may only produce 4-6 litters in a lifetime. The size of newborn pups can be up to 1.5m, and they are highly mobile from birth, further complicating our understanding of where they are born.

Due to the warmer waters brought on by this year’s El Niño, baby shark season has officially begun off the Southern California Coast. White sharks throughout the world move inshore during certain seasons. It is very rare to see adult Great Whites along the Californian coastline. However, the presence of large adult females and then the immediate presence of young pups (<1.5m) strongly suggests that these waters are also a white shark pupping ground from spring – early summer

In Southern California, white shark pups favour many of the same coastal fish species that humans do, like halibut.  So it should come as no surprise that white shark pups are often caught accidentally by coastal fishermen as bycatch.     

Dr Chris Lowe and his students took advantage of this great opportunity to work with local fishermen in the area in order to study baby white sharks.  From their catch/tag/release study, the Lowe Lab found that these white shark pups follow fairly predictable behaviours inshore, staying shallower than the “isotherm” at 60m depth.  Isotherms are boundaries in the water column between warm surface waters and cold deep waters. White shark pups don’t stray deeper than the 60m mark, whether they are in relatively shallow waters or in the deeper waters of the continental slope.  This shows that their choice in habitat relates to water temperature. 

Dr. Lowe and his team release a juvenile white shark back to its inshore waters.

Fewer large predators and an abundance of food, like stingrays and flatfish, draw sharks to the shallower waters

The great white shark is most commonly associated with the coasts of Australia, California and South Africa, but there have been occasions when this increasingly rare animal has been spotted in the Mediterranean. Some experts believe that the Mediterranean is a nursery where great white sharks give birth. The Sicilian channel, near the Italian island of Lampedusa, is the only location in the Atlantic region where both pregnant females and newly born great whites have been sighted. The warm waters of this particular area of the Mediterranean are high in nutrients and attract large pelagic fish, dolphins and turtles which form the staple diet of great whites. This area is a shallow shelf area which keeps the young in warm water throughout the year and reduces competition from blue and mako sharks.

Interesting facts obtained from Dr Lowe and his team:

While it’s rare for white sharks to become stranded on the shore, baby salmon sharks, a close cousin to the white shark, will often strand themselves because of a bacteria that infects their brain and causes them to die, according to Dr Lowe.

85% of all the great white sharks that are by-caught in their study area were <1.75m in length 

These sharks were often found alive when the soak time of the fishing nets was less than 20hr

When released, 92.9% of the pups survived - those are some tough babies!

Published in Latest News
Subscribe to our mailing list
 

capetowntourism fairtrade sasy

saytsa tomsa satsa

tripadvisor