Health of Population
Hooks and Ropes
It is illegal to fish for Grey Nurse sharks, however they still are harmed unintentionally from fishing hooks. All line fishing methods that use hooks have the potential to harm Grey Nurse Sharks. Aside from the countless sightings of these sharks with hooks in their gills, mouth and eyes, autopsies of Grey Nurse Sharks found that hooks can become embedded in the throat and stomach, and can puncture the shark’s large liver. This can lead to bacterial infection, septicaemia (blood poisoning) and ultimately death, and is the largest known source of human-induced mortality of the species.
Under no circumstances should a shark be gaffed or have a tail rope applied to the shark to assist in the removal of fish hooks.
Spot a Shark has successfully helped arrange and conduct 4 rescues of severe hook damage, including the photographed shark with a nasty hook in its eye.
Estimates show that at least a third of the Grey Nurse shark population in East Coast of Australia has a visible hook, or visible damage from hooks. It is unknown how many sharks have hooks inside their gut but it could be greater than 50% of all the sharks.
A natural phenomenon but seemingly common in the East Coast of Australia population is a skeletal disorder known as Scoliosis. Lumpy the shark has had this disorder for many years and is still surviving well and so it does not appear to adversely affect them.
It is not understood why many of the population has scoliosis but it could be due to their limited gene pool from suspected in-breeding or it could be from injuries sustained when lifted out the water as fishing hooks are removed.
Some of the shark population appears particularly skinny and malnourished. This is not a good sign and could indicate internal damage from ingesting a fishing hook that prevents them from properly digesting food.
Another sign that a shark may not be digesting food is if they have algae on their teeth.
It is not known exactly how long a shark may survive in this state and it is not legal to euthanise this species of shark due to its critically endangered status.
Drumlines and Shark Nets
Each year across NSW and QLD a number of grey nurse sharks get caught in the government's lethal drumlines, SMART drumlines and in shark nets as bycatch. Whilst they are not the targets for these programmes it can result in injury or death.
When the sharks are released and reported as alive they can have severe injuries which impede their ability to survive.
This photo was taken by South West Rocks Dive Centre. It is uncomfirmed if this injury was caused by a drumline.