AI Article Synopsis
- Conservation and management of white sharks are hindered by insufficient demographic data, particularly regarding their age and growth rates.
- Researchers utilized radiocarbon dating to estimate the age of white sharks, revealing that the largest female was up to 40 years old and the largest male was 73 years old.
- These findings extend the understanding of white shark longevity, suggest potential differences in growth rates between genders, and indicate that white shark populations may be more vulnerable to human activities than earlier believed.
Article Abstract
Conservation and management efforts for white sharks (Carcharodon carcharias) remain hampered by a lack of basic demographic information including age and growth rates. Sharks are typically aged by counting growth bands sequentially deposited in their vertebrae, but the assumption of annual deposition of these band pairs requires testing. We compared radiocarbon (Δ(14)C) values in vertebrae from four female and four male white sharks from the northwestern Atlantic Ocean (NWA) with reference chronologies documenting the marine uptake of (14)C produced by atmospheric testing of thermonuclear devices to generate the first radiocarbon age estimates for adult white sharks. Age estimates were up to 40 years old for the largest female (fork length [FL]: 526 cm) and 73 years old for the largest male (FL: 493 cm). Our results dramatically extend the maximum age and longevity of white sharks compared to earlier studies, hint at possible sexual dimorphism in growth rates, and raise concerns that white shark populations are considerably more sensitive to human-induced mortality than previously thought.
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|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3885533 | PMC |
| http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0084006 | PLOS |
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