Shark bites are traumatic events that spark fear and anger. Globally, the trend is flat, but in Australia, bites are increasing. Recent incidents near Sydney's beaches have raised concerns among surfers, swimmers, and politicians, though the reasons are not straightforward.
Global Trends vs. Australian Spike
Worldwide, shark bites have remained stable for decades. In 2023, there were 65 unprovoked incidents, close to the 10-year average of 72 bites per year, which mirrors the 20-year and 30-year averages. However, Australia experienced a significant rise: from 12 bites annually in the 2000s to 21 per year this decade.
Sydney's beaches have seen several serious and fatal bites. Earlier this year, bull sharks were involved; in June, a suspected white shark caused life-changing injuries to 34-year-old Leah Stewart, who remains in hospital after multiple surgeries, including amputation of her arm, but is no longer in critical condition.
Factors Behind the Rise
Rob Harcourt, leader of the marine predator research group at Macquarie University and a daily ocean swimmer, says there is no definitive answer but some factors are clear. Population growth is likely a contributor—Australia's population has grown by 7 million in 20 years, though data on water users is scarce. Warming waters are altering shark behaviour: tiger and bull sharks are staying longer in the Sydney area each year.
Increasing humpback whale populations, which migrate along the east coast and serve as food for large sharks, may also influence shark movements. Similarly, recovering seal populations attract sharks. Experts believe sharks often mistake humans for seals, or bite out of exploration or competition for food.
Misconceptions and Mitigation
Despite claims by former Prime Minister Tony Abbott of an "explosion" in shark numbers, there is no evidence to support this. Experts note little change in shark catches in nets. Mitigation measures include drones used by volunteer surf lifesavers, alerts for tagged sharks, and controversial nets and baited lines that trap other marine species and may not reduce risk.
The risk of being bitten remains extremely small. In 2023, Australia recorded five shark bite deaths but 82 drownings at beaches. Humans naturally fear uncontrollable events, leading to disproportionate fear of sharks.
Conclusion
Reporting on shark bites is challenging due to their deadly and life-changing nature. The question of why bites are rising in Australia lacks a clear answer, and one may never emerge.
