What The Greenland Shark Gave Up To Live 400 Years

Three things most documentaries get wrong, and this video corrects: • "It was alive when the first telescopes were turned on Jupiter." Galileo did that in 1610. The central estimate puts the birth of that shark at around 1624. The claim is attached to a number that does not reach it. • "The Greenland shark is blind." Stronger than the evidence carries. What has been demonstrated is heavy infestation of the cornea and progressive damage. Serious visual impairment is a reasonable inference. Total blindness across the population is an assumption repeated until it sounds like a measurement. • "They eat polar bears." The land mammal records — reindeer, moose, horse, the polar bear — are mostly old, anecdotal, and reported long before anyone did systematic stomach content work. Modern surveys come back dominated by fish, with seal a real and recurring component. Scavenging explains the rest. CHAPTERS 0:00 The number, and the range around it 2:03 Welcome to Nethermarine 3:05 The clock hidden inside the eye 5:44 The parasite it does not seem to mind 8:48 Too slow to catch anything, and it does anyway 12:18 Why the meat is poisonous 15:11 What four centuries of living actually cost 18:07 The one number it cannot survive 21:00 The long trade The number it cannot survive is 150. That is roughly how long a Greenland shark takes to reach sexual maturity, and there is no other vertebrate that does this — bowhead whales mature in their twenties, tortoises in their thirties. Through much of the twentieth century these sharks were hunted for their liver oil, tens of thousands a year at the height of it. That fishery collapsed commercially, so the pressure now is quieter: bycatch, hauled up in gear set for something else. The species is listed as Vulnerable by the IUCN. Here is the awkward part. Remove every breeding adult from a region of the Arctic and the survey numbers would not obviously fall for decades, because the animals still swimming were born centuries ago and will go on swimming for centuries more. The population would look intact. The population would be finished. This is an animal that can be functionally extinct long before it looks like it is in any trouble. Nethermarine makes long, slow documentaries about the parts of the ocean that do not get filmed very often, built out of what the science actually says. Subscribe if that is the kind of thing you want more of.