Old & Cold – lifespan of the Greenland shark (Håkjerringa of Havboka)
Fish that were alive during the Age of Enlightenment are still swimming strong. Based on radiocarbon dating, a Greenland shark has lived at least 272 years and maybe as long as 500 years, making the species the longest-lived vertebrate in the world – smashing the previous record held by a 211-year-old bowhead whale. Because of their extreme longevity, Greenland sharks may still be recovering from being over-fished before WW2. The sharks' livers were once used for machine oil, and they were killed in great numbers before a synthetic alternative was found and the demand fell. Sexually mature females and newborn pups are rarely encountered. There are probably quite a few 'tweenagers' swimming around, but it will take them another 100 years to become sexually active. The findings raise concerns about Greenland shark conservation, because a species that takes so long to begin reproducing could be at risk of being over-exploited by fisheries.
Welcome!
When: 22.03.17 at 12.00–13.00
Where:
NFH: LAUD-E102
Location / Campus: Tromsø
Target group: All
Responsible: Ekaterina Nikitina
E-mail: ekaterina.nikitina@uit.no