Norfolk Island tiger sharks grow twice the size of East Coast cousins
Tiger sharks at Norfolk Island reach 4.5 metres long, far exceeding East Coast populations, because they live long and eat abundant prey.
Tiger sharks at Norfolk Island are among the largest in the world, a Flinders University study of tagged sharks has found. The median Norfolk tiger was 4 metres long, with the largest female reaching 4.5 metres and the largest male 4.1 metres.
East Coast tigers are much smaller: the largest female there was about 3.8 metres and the largest male 3.3 metres. The Norfolk sharks grow so big because they live to old age in pristine waters and have access to abundant food.
Only about 5 per cent of their diet comes from cattle offal dumped at Headstone Bay; seabirds make up most of the rest. The sharks roam freely from New Zealand to New Caledonia, rarely troubled by humans.
A federal proposal to expand marine sanctuary protections around Norfolk may help them continue thriving.
- 4.5 metres
- Largest Norfolk female
- 3.8 metres
- Largest East Coast female
- 35
- Sharks tagged in study
- 1400 kilometres
- Distance from mainland
Why it mattersThe study reveals how wildlife populations adapt to their environment and the importance of protected waters for predator survival.
AustraliaNorfolk Island's shark population offers insights into Australian marine conservation and how marine sanctuaries support apex predators.
✓ Claims checked against the source and corrected before publish. checked 5 d ago
