“Oh, we’re above that,” Paine replied. “We’re hyperkeystones.”
We are the influencer of influencers, the keystone species that disproportionately affects other keystone species, the ur-stone that dictates the fate of every arch.
Paine coined the term as a play on ‘hyperparasites’—organisms that parasitize other parasites. There are body-snatching wasps, for example, that lay eggs in the bodies of other insects, and other wasps that lay eggs in the eggs of those first ones—the latter are hyperparasites. So if hyperkeystone sounds grandiose, it’s not meant to; it’s almost the opposite.
The concept is clearest in the Pacific Northwest, the area where Paine and a large number of his students did most of their work. There, in the tidal zone, starfish control the numbers of mussels and barnacles. Sea otters keep kelp forests healthy by eating sea urchins that would graze the fronds down, and orcas hunt the otters. By migrating upstream, salmon carry nutrients from the sea into rivers; when they are killed by bears and wolves, their carcasses are dragged into the forests, where they fertilize the trees.
Bears, wolves, salmon, starfish, orcas, and sea otters: we influence the lot. Whether directly through hunting and fishing, or indirectly through light and noise pollution, climate change, or deforestation, we change the levels of keystone species everywhere.
“People now strongly influence all natural ecosystems,” says Julia Baum from the University of Victoria. “We do so to such an extent that as scientists we cannot even begin to understand how the ecosystems work if we do not first account for the ways in which people are changing them.”
Wait, aren’t we doing that? Isn’t that what ecology is all about?
Sort of, says Worm. He says that he and his peers have been increasingly obsessed with finding big patterns—how fish stocks rise and fall with time, or how communities of species change as temperatures rise. And in doing so, ecology had become a largely descriptive science. But in the meantime, it moved away from what Paine called “kick-it-and-see ecology”—experimental work that, like his starfish study, would reveal not only what is changing, but why and how.
“Bob felt that we had lost the way a little bit,” says Worm. “In the media, you read that we’re losing species, and birds are affected by plastic pollution, and tigers are dwindling, and that’s bad. That’s often the extent of it. But there’s a deeper and more profound side to this. Those losses set off these cascading interactions that we only know about in a few settings, largely because of people who are now in their seventies and eighties, like Bob.”
A few more recent examples hint at what we’re missing. In the northwest Atlantic, we overfished big sharks, releasing smaller sharks and rays from predatory control; they devoured shellfish and caused a century-old scallop fishery to collapse. In Ghana, we killed off lions and leopards in Ghana, allowing baboons to flourish; they then ate other primates, small antelopes, birds, and even crops, forcing local villagers to enlist school-age children as crop guards. In both cases, the direct consequences of our actions were clear, but it took a lot of work to understand everything that happened afterwards.