When will the slaughter end?

Nick Pyenson, curator of fossil marine mammals at the Smithsonian Institute in Washington, is quick to tell us he’s not a ‘whale hugger’. ‘I didn’t fall asleep snuggling stuffed whales or decorate my room with posters of humpbacks suspended in prismatic light.’ Pyenson sees whales through their ancestral bones, and their contemporary entrails, digging up their past or scrying their future. Spying on Whales begins its surveillance in the fossil-rich site of Cerro Ballena (‘Whale Hill’) in the Atacama desert. Here, in the Miocene layers, he uncovers an entire pod of ancient, stranded whales, stilled in the moment of their deep-time death. It’s an Indiana Jones moment. He may disavow cetacean sentimentality in favour of scientific rigour, but Pyenson can’t resist enlivening his exploits with a boyish excitement.

And it is an exciting world, this one of prehistoric whales: 600 extinct species —compared to the current 85 extant ones — which include the wondrous ‘walrus whale’, a mash-up of the Arctic tuskers with dolphin-like bodies; and the ferocious ‘killer sperm whale’, arrayed with canines in both upper and lower jaws. In Pyenson’s evocative phrase, the Miocene is

a kind of fever dream of the present, drawing on familiar members of today’s ecosystems, in similar settings, but with occasional aberrant and nightmarish forms.

But it’s when Pyenson turns to our era that things become really interesting. Drawing on his whale evolution work, he notes that modern whales are even more monstrous than their forebears, reaching 100 feet or more in the case of the blue whale, an animal whose size may only be restricted by the size of its mouth and the attendant drag factor on its yawning jaws.

Could whales get any bigger, he asks? His answer comes in the slaughter of the last century, when the whaling fleets of Norway, the Soviet Union, Japan and Britain, mostly working in the Southern Ocean, killed the largest whales, thereby destroying the genetic strength of populations and the actual size of subsequent individuals.