One quarter of the world's cartilaginous fish such as sharks and rays are in danger of disappearing within the next few decades.

The survey is the first to stretch their observations into "coastal seas and oceans." They found 249 (one-quarter) out of 1,041 shark, chimaera and ray species are considered threatened under the IUCN red list, a Simon Fraser University news release reported. large_great-white-shark A quarter of ray and shark species are in grave danger. We now know that many species of sharks and rays, not just the charismatic white sharks, face extinction across the ice-free seas of the world," Nick Dulvy, a Simon Fraser University (SFU) Canada Research Chair in Marine Biodiversity and Conservation, said in the news release. "There are no real sanctuaries for sharks where they are safe from overfishing." A study involving 300 experts and taking place over 20 years took "distribution, catch, abundance, population trends, habitat use, life histories, threats and conservation measures" into account when looking at the conservation status of the species'. One-hundred-and-seven species of rays and skates and 74 shark species were defined as "threatened." Only 23 percent of all the species studied were considered to be of "Least Concern." The team found the regions where these species were most threatened were the Indo-Pacific, the Red Sea, and the Mediterranean. In the most peril are the largest species of rays and sharks, especially those living in relatively shallow water that is accessible to fisheries. The combined effects of over exploitation -especially for the lucrative shark fin soup. manta ray Manta rays are large eagle rays, , typically with large triangular pectoral fins and forward facing mouths. A whole bunch of wildly charismatic species is at risk. Rays, including the majestic manta and devil rays, are generally worse off than sharks. Unless binding commitments to protect these fish are made now, there is a real risk that our grandchildren won't see sharks and rays in the wild," he said. Losing some of the aquatic food chain's top predators could cause problems throughout the entire ecosystem. The loss of these species would also be like losing "a chapter of our evolutionary history," according to Dulvy. "They are the only living representatives of the first lineage to have jaws, brains, placentas and the modern immune system of vertebrates," he said.    

 

 

Published in Marine Wildlife
Thursday, 28 February 2019 13:36

White Shark Facts

Did you know that....

  • White Sharks are also known as Great White Sharks, Carcharodon carcharias(Latin) and White Pointer Sharks.
  • 070507ali1 080812IMG_9024
  • Their bodies are counter-shaded with a charcoal to black, grey or even dark brown top (dorsal surface) and completely white underneath (ventral surface)
  • Counter-shading makes it difficult for their prey to see them
  • One of the most successful predators in the world
  • Live on a diverse diet of fish, other sharks, seals, dolphins and even scavenge on dead whales
  • They have many different ways to catch their food from chasing fish, to sneaking up on stingrays to attacking from below when trying to eat seal
  • Have taste buds inside their mouth and throat and are more fussy than other sharks like tiger sharks
  • Have a lateral line made of special hair-like cells which runs from their tail to their head and can detect small water vibrations and currents 090711DSC_0286
  • Use their electrosense to detect the electric field given off by all living animals and can even find prey hidden under the sand
  • They are sensitive to low frequency sounds as produced by struggling prey
  • They use body language and smell to communicate with one another

  • Deepest recorded dive was over 1200
  • Can breach out of the water over 2m into the air
  • One of the most widely distributed sharks found in all oceans, except the polar seas
  • Areas with the highest concentrations are Western Cape, South Africa, South Australia, West coast USA, Guadalupe Island Mexico and New Zealand
  • Found near the coast and in deep oceanic waters
  • Grow slowly only becoming mature after 10 years (males) and 15 years (females)
  • Live for more than 60 years
  • Reproduce slowly with litters of 2 - 10 baby sharks, called pups
  • Gestation is thought to be over 12 months
  • Give birth to live young (viviparous)Each pup is between 1.2 - 1.7 meters long when it is born
  • There is no parental care
  • World's largest predatory shark/fish growing up to 6.1 metres
  • Females grow bigger than male 09080224-03-09
  • They weigh over 2000 kgs
  • They have six senses: sight, smell, taste, touch, hearing and electroreception
  • They can see in the day and at night and can see colour
  • They don't have eyelids, but instead roll their eyes back to protect them
  • Sometimes they will stick their heads out of the water which is called spyhopping
  • They have the strongest smell out of all sharks and can smell one drop of blood in a million parts water
  • Man kills over 100 million sharks a year,
  • Sharks cause less than five deaths worldwide per year.
  • Chairs and toasters kill more people than sharks
  • Great White Sharks are Vulnerable to Extinction

 

Published in Sharks

 

 

 

 

 

--

For nature lovers

  • Big 5 Game Safari
  • Whale watching
  • ECO - Marine Tours
  • Shark Tours
  • Penguin & seabird

For the connoisseur

  • Wine tasting
  • Arts & culture
  • Scenic Drives
  • Cape Aghulas Tour
  • Hermanus Tour

For the adventurous

  • Shark cage diving
  • Mountain biking
  • Quad bike tours
  • Cape Town Zipline
  • Paragliding

Truck

Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet.

Storage

Vero eros et accumsan et iusto odio dignissim qui blandit praesent luptatum zzril delenit augue duis dolore te feugait.

Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volutpat. Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper.