That’s a hard question to answer as the best way to get age information from the giants is to measure the amino acid levels in their eyes.
But an easier dating tool was found in a bowhead whale that was killed off of the coast of Alaska earlier this year. Embedded in the whale’s neck was an arrow-shaped tool, about three inches long, that was patented in 1879. So whale experts are figuring that the bowhead survived some kind of fishing attack at least 100 years ago. They’ve targeted the whale’s age to be between 115 and 130 years old.
In fact, the particular type of arrowhead found in the whale was groundbreaking for its time. It was filled with explosives that were supposed to go off on impact to further hurt the whale. With the particular case, that didn't work out, and the whale was probably annoyed, but not stopped, by the hit.
It’s rare to find centurion whales, but a few can live that long and there are documented cases of whales living to be 200 years old.
The captured Alaskan bowhead was 49 feet long and was speared using today’s more modern technology. It’s capture was completely legitimate. The Alaskan Eskimo Whaling Commission allows native villagers to take up to 255 whales from Alaskan waters each season