Great white sharks, top predators of the world oceans, may live far longer than previously thought - up to 70 years and more, according to a new study.
Researchers used radiocarbon dating to determine age estimates for adult white sharks, also known as great whites, in the Northwest Atlantic Ocean.
The first successful radiocarbon age-validation study analysed vertebrae from four male and four female white sharks (Carcharodon carcharias) caught between 1967 and 2010 in the Northwest Atlantic Ocean.
Researchers from National Oceanic and Atmospheric Administration (NOAA) and the Woods Hole Oceanographic Institution (WHOI) compared radiocarbon values from the shark vertebrae with reference chronologies documenting the marine uptake of carbon 14 produced by the atmospheric bomb testing.
Samples were dated and the result was the first radiocarbon age estimates for adult white sharks.
Estimated bomb radiocarbon dating age of the oldest female white shark sampled was 40, and for the oldest male 73.
Ages for the three other males were 9, 14, and 44, while the other females sampled had estimated ages of 6, 21, and 32.
Previous studies of white sharks from the Pacific and Indian Oceans suggested that none of the examined specimens were older than 23 years.
Researchers suggest that either white sharks are living significantly longer and growing slower in the Northwest Atlantic than either the Pacific or Indian Oceans, or longevity has been underestimated in previous studies.
Knowledge is limited about the age and growth rates of white sharks, apex predators that live in coastal and offshore waters throughout the world.
Sharks are typically aged by counting alternating opaque and translucent band pairs deposited in sequence in their vertebrae.
It is unclear whether these band pairs are deposited annually, making it difficult to accurately estimate age or provide estimates for longevity for many shark species.
The study was published in the journal PLOS ONE.