Humanity is on the verge of causing something unprecedented in Earth’s history—a mass extinction unlike any that has come before.
For the first time ever, the largest marine creatures are vanishing before the smaller ones.
This is a sharp departure from previous extinction events, where size did not determine survival.
But in today’s world, the bigger the species, the higher the risk of being wiped out.
Why Size Matters in Modern Extinction
According to a recent study led by Stanford University paleobiologist Jonathan Payne, there is a direct correlation between body size and extinction threat.
“We’ve found that extinction threat in the modern oceans is very strongly associated with larger body size,” Payne explains. The primary reason? Humans.
For centuries, we have hunted large species for food, sport, and resources, drastically reducing their populations.
This practice has now reached the deep ocean, where industrial fishing technology enables humans to harvest marine life at an unprecedented rate.
To understand how serious this trend is, Payne and his team analyzed fossil records dating back 445 million years.
They found that in past extinction events, smaller marine creatures were more likely to disappear, or size did not play a role at all. But today, the rules have changed.
The Bigger They Are, the Harder They Fall
The numbers are shocking. Payne’s study reveals that for every tenfold increase in body size, the odds of being threatened by extinction rise by a factor of 13.
In other words, the larger the species, the more likely it is to be in danger.
This pattern spells disaster for ocean ecosystems. Larger marine animals are crucial for maintaining ecological balance.
They regulate food chains, cycle nutrients, and help sustain the health of marine environments.
Losing them could cause cascading effects, destabilizing entire ecosystems.
Extinctions Have Never Looked Like This
Traditionally, extinctions were driven by natural disasters—asteroid impacts, volcanic eruptions, or sudden climate shifts.
When the dinosaurs perished 66 million years ago, they did so alongside creatures of all sizes.
But today, the driving force behind this extinction event is neither nature nor chance. It is human activity.
“We see this over and over again. Humans enter into a new ecosystem, and the largest animals are killed off first,” says researcher Noel Heim.
For most of history, marine life was relatively safe from human impact. Unlike land animals, deep-sea creatures were beyond our reach.
That is no longer the case. With modern industrial fishing fleets, humans now have the technology to hunt and deplete fish populations on a global scale.
Why It’s Worse Than You Think
If you assume that eliminating large marine species might benefit smaller ones, think again. Smaller species do not necessarily thrive when their larger counterparts disappear.
In fact, they often struggle, as food chains collapse and marine ecosystems become unbalanced.
According to the study’s authors, the loss of large ocean creatures poses a disproportionate threat to the entire ecosystem.
Their presence is crucial for maintaining the natural order of the seas.
Without them, oceanic food webs could crumble, leading to unpredictable and potentially irreversible consequences.
The One Thing We Can Change Right Now
Unlike climate change, which requires long-term global efforts to reverse, the overfishing crisis is something we can fix immediately.
Unlike ocean acidification or rising sea temperatures—both of which could take centuries to stabilize—fish populations can recover relatively quickly if given the chance.
“We can change treaties related to how we hunt and fish,” Payne states.
“Fish populations have the potential to recover much more quickly than climate or ocean chemistry.”
This means that enforcing sustainable fishing practices, banning destructive techniques like bottom trawling, and establishing marine protected areas could drastically slow down the extinction crisis.
We Are Not Too Late—Yet
The study makes one thing clear: we still have a choice.
The sixth mass extinction is not yet inevitable. But if we continue on our current path, we may soon cross a threshold from which there is no return.
“We have the opportunity to totally avert this, if we make the right decisions,” Payne told Gizmodo.
“To claim we’re in a sixth mass extinction is something very enormous. It is a possibility. It is not the reality yet.”
The fate of Earth’s oceans is still in our hands. The question is: What will we do about it?
