Whale Teeth Reveal Life Stories Via Nuclear Fallout

Researchers have employed a groundbreaking 'dental time machine' method, utilizing sophisticated radiocarbon dating on whale teeth, to reconstruct the life stories of marine animals. This technique analyzes radioactive fallout from mid-20th century nuclear weapons testing, which is preserved in the annual growth layers of whale teeth.

By examining these layers, scientists can ascertain a whale's age and infer details about its diet and environment. The study focused on teeth from three killer whales and two sperm whales that died on Scottish shores in recent decades.

One analyzed sperm whale, Moby, stranded in the Firth of Forth in 1997, was determined to be at least 43 years old. His teeth's inner layers predated significant nuclear fallout in the marine environment.

Another specimen, a killer whale named Lulu stranded in 2016, showed a 'Sellafield signal' from radiocarbon discharges, distinct from direct nuclear testing fallout. Analysis of a killer whale from South Uist suggested an age of 65 or more, potentially one of the oldest recorded.

This research, combining radiocarbon and stable isotope analysis, was led by scientists at SUERC: Centre for the Isotope Sciences in partnership with several Scottish universities and National Museums Scotland. It aims to deepen the understanding of killer whale and sperm whale life histories.