Dating a whale's age with an 1879 patent: what the Barrow fragment established about bowhead longevity

Determining the age of a bowhead whale is a genuine methodological problem: the species has no teeth to section, and it does not form the earwax plug whose layers are used to age other mysticetes. In May 2007, a subsistence catch in Alaska yielded a piece of evidence of unusual precision on this question: a metal fragment of industrial origin, dated by its patent, lodged in the skeleton of an animal that was still alive.

The object and the circumstances of its discovery

On 16 May 2007, the crew of Captain Arnold Brower Sr. was flensing a bowhead whale near Barrow, Alaska, as part of the Inupiat subsistence hunt regulated by the Alaskan whaling commission and the United States oceans administration. A metal fragment came to light during the butchering and was handed to Craig George, a biologist with the North Slope Borough.

Two clarifications are needed, because successive retellings of the episode have lost them along the way. The object is not a harpoon but the fragment of a bomb lance: a metal cylinder charged with explosive and fitted with a delay, fired from a shoulder gun and designed to detonate inside the animal a few seconds after impact. And it was not in the neck, but embedded in the right shoulder blade.

First method: dating the object by its typology

The fragment was compared with the collections of the New Bedford Whaling Museum by John Bockstoce, associate curator. The dating proceeds by successive cross-checks, each one narrowing the interval.

The typology of manufacture. The piece matches a model patented in 1879 by Ebenezer Pierce, of New Bedford. Pierce amended that patent in 1885, improving the firing mechanism. The fragment does not show that modification, which places its manufacture between 1879 and 1885.

The ownership marks. The point bears six small notches, interpreted as the marks of an Indigenous whaling captain. The object was therefore not fired from a commercial ship, but by an Inupiat crew.

The regional chronology. Inupiat hunters took up industrial weaponry only after commercial shore whaling stations were established, in 1884 at Point Barrow and in 1887 at Point Hope. Since stocks of bomb lances ran out quickly, these three elements taken together place the shot in the late 1880s.

What this dating allows one to conclude

The reasoning is simple, but it is worth setting out explicitly, because the figure most often quoted does not survive it. Between a shot placed in the late 1880s and a death in 2007, about 120 years elapse. Since the animal must have been large enough to interest hunters at the moment it was struck, its total age is greater than that value.

The range of 115 to 130 years that circulated in the press therefore rests on a later date for the shot than the one the museum settled on. The lower bound of 115 years is incompatible with a survival of 120 years after the impact. What the fragment establishes with certainty is a minimum, and that minimum is more than a century.

The case is not an isolated one: stone points and bone harpoon heads, far older, have been found in the blubber of other bowheads taken in recent years. What is singular here is the precision, since a manufactured and patented object can be dated to within a few years.

Second method: aspartic acid racemisation

The standard method for ageing the species relies on the lens of the eye, a tissue whose nucleus is not renewed at any point in the animal’s life: the molecules present in it at birth stay there.

What is measured in it is the racemisation of aspartic acid. This amino acid exists in two forms that are mirror images of one another, like a left hand and a right hand. Proteins synthesise only one of them, and time slowly tips the proportion towards an equal mixture, at a known rate. The ratio between the two forms therefore works as a chemical clock. Applied by Craig George and colleagues in the Canadian Journal of Zoology in 1999, it gave one male estimated at 211 years and three others beyond the century.

Method	What it measures	Precision
Bomb lance fragment	Time elapsed since impact	A few years on the date of the shot, but gives a minimum age only
Racemisation in the eye lens	Total age of the individual	Wide margin of error, growing with age
Stone or bone artefacts	Predating industrial weaponry	Indirect dating, poorly resolved

Caution is called for on the figure of 211 years. The margin of error of the method is wide, as the authors themselves stress, and this value is the top of a range rather than a measurement. What all the approaches together do establish firmly is that the species commonly exceeds a century, which makes it the longest-lived mammal known. Our page on cetacean records places this figure alongside the others.

The underlying biological mechanism

Longevity of this order raises a well-known theoretical problem. An animal of eighty tonnes has several thousand times more cells than a human, and therefore that many more opportunities for a mutation to initiate a cancer. Set against two centuries of life, the cumulative risk ought to be considerable. It is not, which implies a protective mechanism.

A study published in Nature in 2025 by the teams of Vera Gorbunova and Andrei Seluanov, at the University of Rochester, identifies one component of it. Bowhead whale cells contain the DNA repair protein CIRBP at concentrations roughly a hundred times higher than those of other mammals. This protein acts on double-strand breaks, the most damaging lesions in the genome.

The strategy is notable by contrast. Many long-lived species limit tumour risk by eliminating their damaged cells. The bowhead repairs them, and with high fidelity. The functional test supports the hypothesis: introduced into cultured human cells and then into Drosophila, the whale protein improved DNA repair in both systems, and lengthened the lifespan of the flies. CIRBP production also rises when the temperature falls by a few degrees, which takes on a particular meaning in an Arctic animal. Our pages on sequenced genomes and cetacean life cycles develop this ground.

What the Barrow case illustrates beyond longevity

One last element is worth noting, and it belongs less to biology than to history. This animal carried the fragment of an explosive charge in its shoulder blade for about 120 years. It survived the commercial whaling that reduced its Arctic population to a fraction of its original numbers, and it was still swimming at the start of the twenty-first century.

The dating of the fragment is, finally, the result of a collaboration between the Inupiat hunters who passed it on, the North Slope Borough wildlife department and a New England museum holding the reference collections. The fragment is now on display at the Inupiat Heritage Center in Barrow.

Sources: press release from the New Bedford Whaling Museum of 7 June 2007, with the North Slope Borough Department of Wildlife Management; George J. C. et al., “Age and growth estimates of bowhead whales (Balaena mysticetus) via aspartic acid racemization”, Canadian Journal of Zoology, 1999; “Evidence for improved DNA repair in the long-lived bowhead whale”, Nature, 2025, and the University of Rochester press release.