Threats From Fishing
Despite legal protections in Australia, grey nurse sharks continue to face significant risks from fishing activities. While targeted fishing is prohibited, incidental bycatch remains a major concern, particularly at known aggregation sites. Sharks can accidentally ingest fishing gear, leading to severe injuries and mortality.
Autopsies frequently reveal hooks embedded in their throats, stomachs, and even livers, causing infections, septicemia and death.
It is crucial to avoid handling or harming these protected animals. The Spot a Shark team has documented numerous cases of hook injuries, with a substantial portion of the grey nurse shark population having fishing-related injuries.
Video Credit: Joe at South West Rocks Dive Centre
Scoliosis
Scoliosis is a skeletal disorder that the Spot a Shark team has documented in at least 10 individual sharks. The most famous is Lumpy (GNS-1045) who has been sighted regularly by the diving community in Sydney, Broughton Island, and Kiama. Some sharks in our database appear to be perfectly healthy and then suddenly have scoliosis. Others appear to develop scoliosis over time and it appears to get worse with each passing year. While the exact causes of scoliosis in grey nurse sharks remain unclear, several factors may contribute, which include:
- Genetic factors: Inbreeding within the population could lead to inherited health issues, including scoliosis. This theory is supported further by evidence of the limited gene pool within this species.
- Injuries: Handling of these sharks, such as in the removal of fishing hooks, can cause trauma that may contribute to spinal deformities.
- Environmental factors: Pollution in the water could potentially impact embryonic development and lead to abnormalities like scoliosis.
The Spot a Shark team uses images collected to assist researchers (including Professor Adam Stowe and Nik Otway) to help understand this condition further. This knowledge will help inform conservation efforts and potentially improve the health of the population.
Starvation
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.
Photo credit: Geoff Aquino
Shark Nets
Photo credit: Peter Simpson
Shark nets have been installed across NSW and QLD since 1937, in the name of bather protection from dangerous shark species. However, scientific evidence overwhelmingly demonstrates the ineffectiveness of these nets.
High bycatch rates and threatening endangered species: Shark nets have a significant problem with bycatch, capturing and killing numerous non-target species. In recent years, nets have caught more turtles than target sharks. In fact, over 90% of animals caught in these nets are not the intended target species. Every year dolphins, turtles, rays, seals and whales are caught and approximately 60% of the bycatch died. The impact on grey nurse sharks, a critically endangered species is particularly concerning. Between 2012 and 2024, as many as 166 critically endangered grey nurse sharks have been caught in the nets with nearly half of them dying.
The government has officially recognized shark nets as a key threatening process and major threat to the survival of the grey nurse shark species.
False sense of security: The shark nets do not stretch the beach, do not reach the floor, do not reach the surface. Sharks swim over, under and around them. With the high rate of bycatch caught in these nets, the concern is that the nets attract and lure dangerous sharks to shore. The lack of awareness about these factors is a key concern, with people having a false sense of security.
The continued use of shark nets despite their proven ineffectiveness raises serious concerns about their impact on marine ecosystems. The Spot a Shark team tries to raise awareness and encourage people to move toward modern alternatives only. Learn more at www.savingnorman.com.au
