• Shark cage diving in Gansbaai, South Africa with Marine Dynamics. Experience the exceptional and come face to face with a great white shark! 

  • The exact world record white shark is a contested issue, but chances are it is between 6-7m. In Gansbaai, the largest white shark ever caught was at Danger Point and measured up to 5.9m.

  • If you see a white shark in the water don’t panic. Chances are high that the shark has already detected you and isn’t interested. White shark attacks are normally associated with poor visibility, so avoid murky conditions.

  • White sharks have a unique system called a “counter current heat exchange”, which keeps their body  tempreture +/- 7C above the surrounding water temperature. 

  • All sharks have an incredibly unique system on the tip of their nose called the “ampillae of Lorenzini”. These are small pores filled with a gel that transmits the electrical currents in the water to the shark’s brain so that it can assess its environment.

  • White sharks give birth to live young (not eggs), and they give birth to 6-8 pups at one time. Pups are usually between 1.0-1.5m in length and are born with teeth.

  • Body language has been a well documented form of shark communication and has identified body arching, jaw gaping, and other postures as specific social tactics.


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Thresher shark necropsy at the Dyer Island Conservation Trust

Monday, May 07, 2018 |  0 Comment

Author: Marine Dynamics (Shark Cage Diving Company)
Marine Dynamics is a Shark Cage Diving company based in Kleinbaai, a small harbour town, part of Gansbaai in the Western Cape of South Africa. This area is known as a hotspot for the Great White Shark and the best place in the world to see and dive with these iconic creatures in their natural environment.

On Sunday 6th of May, at 2h30 pm, a deceased shark was reported to the Dyer Island Conservation Trust. The Marine Dynamics team with the help of their international marine volunteers retrieved the animal from the high tide mark at die Skip near Pearly Beach. The necropsy was led by PhD candidate, Alison Towner and took place at the volunteer lodge the next day.

Exactly a year to the day that two orcas killed four white sharks in the Gansbaai area (see link to Marine Dynamics timeline) and concerns were that this could be connected as the now infamous ‘Port and Starboard’ were recently seen in Western Cape waters. However, the necropsy provided no evidence to pin point a cause of death.

The shark measured 4 metres from its head to the end of its enormous tail, which makes up half its body length. It was a reproductively mature male as determined by the calcified condition of its claspers (external mating appendages). “There were no obvious signs of trauma or fishing related damage/gear on this shark. We opened the shark and found an intact liver - it seemed to be in good condition,” said shark biologist Alison Towner. “It was fascinating for the team to compare the different internal shark anatomy with the great whites they had previously worked with.” The shark had remnants of fish vertebrae in its stomach contents.  Tissue samples were collected for genetic and diet studies along with body measurements.

Thresher sharks are known in Afrikaans as ‘Sambokhaai’. They use their tremendous whip like tail to stun and kill their prey and are capable of fully breaching the surface of the water. Compared to great whites their jaws and teeth are very small as most of their hunting power comes from their tails. There are three types of Thresher shark, the pelagic, the big eye and the common. All three have high value meat and were listed last year on CITES appendix 2. They are also listed as vulnerable on IUCN, the same as the great white sharks. It was agreed that this specimen was a common thresher shark (Alopias vulpinus). They are rare in South Africa and this was a first for the Dyer Island Conservation Trust team.

Special thanks to Koos and Hanneke De Wet who together with their children discovered the shark and reported it to Alison Towner. Special thanks to those who assisted with the necropsy. 

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