Animal Feature – Grey Nurse Sharks at Shark Cave
The first instinct when most people see a Grey Nurse Shark (Carcharias taurus) is “I want to be as far away from that as possible”. Unfortunately that fear combined with it’s fierce appearance lead to overfishing, the shark was prized and targeted as a trophy catch. The Jaws with rows of teeth were often sold or seen wall mounted.
Grey Nurse Sharks are also known as Sand Tiger Sharks or Ragged Tooth Sharks overseas, their conservation status is listed as vulnerable. They are classified as a protected species in Western Australia. The GNS only gives birth to two pups once every two years and females are only able to reproduce after the age of 6-8 years which means human impacts can very quickly decimate their numbers in the wild.
Despite the terrifying toothy gaze, Grey Nurse sharks feed on fish and are known to be passive and placid when observed by divers.
Welcome back Al!
Perth SCUBA divers are lucky enough, when the weather is just right, to meet the real GNS. Local dive boats will guide advanced divers to the specific sites the sharks live in, about an hour’s boat ride from Perth. This year an old familiar face made a reassuring come back.
“This week we were lucky enough to head out to one of our favourite sites to visit our shark friends. Unfortunately one of them had a large chunk missing just below and connecting to it’s gills. Chatting with Alex Hoschke, author of the Rottnest Island fish book, we learnt the shark’s name is Al, or M152.” Kate Scollary, Bucket List Diver.
Alex Hoschke told us “He’s been around with the same wound since at least 2016 so it doesn’t seem to be slowing him much! It’s good to know he’s still around though, and to see the first sighting for 2021! It’s amazing that he’s survived.”
Ian “Sharky” Jones was the first to Photograph Al the Grey Nurse Shark, shown above and below. He named him Al, after Al “Scarface” Capone. Check out some of Sharkey Jones’ vlogs on the Aquatic Australia YouTube channel.
How to ID a Grey Nurse Shark
Apart from wounds and scars, divers lucky enough to observe these gentle giants up close have identified individual sharks by photographing the faint bronze/brown spots down their sides. Other useful information could include a size estimate from the tip of the nose to the tip of it’s tail, the date and the site location.
Grey Nurse sharks usually swim in repetitive circuits, so it’s best to pick a spot and stay close to the bottom to wait for them to cruise past you.
Do you have any clear identifiable images of a Western Australian Grey Nurse Shark? If so we’d love to see them and pass them on to see if any are already Identified. Email your pictures to [email protected] with any information on the date and location.
It’s suspected that Al’s injury was related to amorous activities. Sharks are known to bite their mates during the act. The Grey Nurse Shark is known to be Ovoviviparous, it carries it’s offspring in it’s uteri (it has two uteri!) but they are formed in eggs rather than attached to an umbilical cord. The first of the baby sharks to grow large enough will then survive by eating it’s yolk and then it’s siblings! Two live pups are usually born.
Pups are born around a meter long and are mature at about 2 meters in length, adults have been known to reach around 3.5 meters.
You can help save the GNS by refusing to buy souvenirs such as shark teeth and by finding out if your seafood is ethically and sustainably sourced.