The devastation of the vast majority of the world's marine life is much closer than we think.
Picture a beach along the same vast ocean you know today—the same powerful waves and shifting tides, reflecting the same beautiful sunsets, even the same green-blue water. Now imagine a crowd gathered at the shoreline, standing in a big circle, gawking at something that just washed up. Kids tug on their parents’ shirt sleeves, asking questions about the dead creature lying on the sand. Reporters arrive. The story is momentous even if the takeaway isn’t much fun. Everyone knows there used to be fish in the oceans—kind of like the ones that still live in some rivers and lakes, except they could be much bigger, sometimes meaner, more diverse, more colorful, more everything. But those mythical ocean fish all died. Except maybe this one. This one was alive in there, and now it’s dead too.
According to Stanford University paleobiologist Jonathan Payne, an expert in marine mass-extinction events, a scenario where all the ocean's fish, mammals, and other creatures—even tiny animals like krill—are all gone is far from science fiction. The type of die-off that would lead to a largely lifeless ocean has happened before, and we're well on our way to seeing it happen again.
To get into Payne's frame of mind, we have to look at two areas of history. First, there's pre-dinosaur times, where we can find a precedent for the kind of huge-scale extinction we're seeing now. Then, we have to look at the past few hundred years, to understand why our fishless future kind of looks like, uh, the present.
We know that, about 250 million years ago, some extremely bad stuff happened, because almost everything on Earth that was alive at that time died very quickly, taking only a few million years to die off. This event is not to be confused with the meteorite impact that happened 65 million years ago—the one that supposedly wiped out the dinosaurs. That was nothing. A lot of those dinosaurs never went truly extinct; they're now known as "birds," and quite a few mammals made it, and evolved into humans, in pretty short order. This earlier event, the Permian–Triassic Extinction, is frequently called "the Great Dying" by paleontologists who like historical events to sound like Morrissey album titles. It made the Earth pretty quiet for a while—the oceans quietest of all.
In 2017, Payne and several colleagues looked into the source of the aforementioned extremely bad stuff that led to the Great Dying. They concluded that temperature-dependent hypoxia—loss of oxygen due to changes in temperature—caused about 70 percent of the losses. An oddly familiar culprit was fingered for this temperature change: "rapid and extreme climate warming." Payne and his pals weren't the first to draw comparisons between the events leading up to the Great Dying and the changes we're seeing today. A previous study had found that the Great Dying had resulted from rising carbon emissions—caused at that time by geothermal events—that occurred over the span of two to 20 millennia; in other words, the blink of a geological eye.
"The relevant thing we know from these recent results is that the patterns of warming, and loss of oxygen from the ocean that can account for the extinction at the end of the Permian are the same features we're starting to see right now," explained Curtis Deutsch, a chemical oceanographer at the University of Washington and one of Jonathan Payne's colleagues on that 2017 study.
Thanks to our species' multi-pronged and comprehensive approach, humanity's present day "Kill All the Marine Life" project is going extremely well. Here's a quick cheat sheet listing our main strategies:
"Shifting baselines" have to do with everyone's gut-level perception of the natural world. The term refers to our tendency to perceive our own early experiences of ecology as the norm, in contrast to what we see later in life. To explain with a non-oceanic example, my own childhood memories of summers in California's Inland Empire include street gutters choked with thousands of California toads. Twenty years later, those toads are mostly gone—likely decimated by chytrid fungus infections. Their loss leaves me with the false impression that the natural order in Southern California has vanished in a very short time, when actually, the damage humanity has caused here is of much longer duration and much larger in scale than the loss of one species of toad (a species that arguably wasn't "supposed to be there" in the first place). Much more serious losses of biodiversity have been rolling out for centuries, but I don't miss animals like the Southern California kit fox, which went extinct over a century ago, because my own baseline never included them.
Similarly, according to Deutsch, we won't collectively care about the death of all the fish, because when it finally happens, our baselines will have shifted so much that the lack of fish will seem normal.
by Mike Pearl, Vice | Read more:
Image: Cathryn Virginia
Picture a beach along the same vast ocean you know today—the same powerful waves and shifting tides, reflecting the same beautiful sunsets, even the same green-blue water. Now imagine a crowd gathered at the shoreline, standing in a big circle, gawking at something that just washed up. Kids tug on their parents’ shirt sleeves, asking questions about the dead creature lying on the sand. Reporters arrive. The story is momentous even if the takeaway isn’t much fun. Everyone knows there used to be fish in the oceans—kind of like the ones that still live in some rivers and lakes, except they could be much bigger, sometimes meaner, more diverse, more colorful, more everything. But those mythical ocean fish all died. Except maybe this one. This one was alive in there, and now it’s dead too.
According to Stanford University paleobiologist Jonathan Payne, an expert in marine mass-extinction events, a scenario where all the ocean's fish, mammals, and other creatures—even tiny animals like krill—are all gone is far from science fiction. The type of die-off that would lead to a largely lifeless ocean has happened before, and we're well on our way to seeing it happen again.
To get into Payne's frame of mind, we have to look at two areas of history. First, there's pre-dinosaur times, where we can find a precedent for the kind of huge-scale extinction we're seeing now. Then, we have to look at the past few hundred years, to understand why our fishless future kind of looks like, uh, the present.
We know that, about 250 million years ago, some extremely bad stuff happened, because almost everything on Earth that was alive at that time died very quickly, taking only a few million years to die off. This event is not to be confused with the meteorite impact that happened 65 million years ago—the one that supposedly wiped out the dinosaurs. That was nothing. A lot of those dinosaurs never went truly extinct; they're now known as "birds," and quite a few mammals made it, and evolved into humans, in pretty short order. This earlier event, the Permian–Triassic Extinction, is frequently called "the Great Dying" by paleontologists who like historical events to sound like Morrissey album titles. It made the Earth pretty quiet for a while—the oceans quietest of all.In 2017, Payne and several colleagues looked into the source of the aforementioned extremely bad stuff that led to the Great Dying. They concluded that temperature-dependent hypoxia—loss of oxygen due to changes in temperature—caused about 70 percent of the losses. An oddly familiar culprit was fingered for this temperature change: "rapid and extreme climate warming." Payne and his pals weren't the first to draw comparisons between the events leading up to the Great Dying and the changes we're seeing today. A previous study had found that the Great Dying had resulted from rising carbon emissions—caused at that time by geothermal events—that occurred over the span of two to 20 millennia; in other words, the blink of a geological eye.
"The relevant thing we know from these recent results is that the patterns of warming, and loss of oxygen from the ocean that can account for the extinction at the end of the Permian are the same features we're starting to see right now," explained Curtis Deutsch, a chemical oceanographer at the University of Washington and one of Jonathan Payne's colleagues on that 2017 study.
Thanks to our species' multi-pronged and comprehensive approach, humanity's present day "Kill All the Marine Life" project is going extremely well. Here's a quick cheat sheet listing our main strategies:
- We dump several metric tons of plastic garbage into the oceans every year.
- Bottom trawling, or dragging fishing equipment across the seafloor, is turning "large portions of the deep continental slope into faunal deserts and highly degraded seascapes" according to a 2014 report on the long-term effects of this widespread practice.
- The planet is heating up really fast, and the resulting extinctions are happening in real time. (Although, for the record, at this rate it will take a few more centuries for this effect to reach the lifeforms at the deepest depths of the oceans.)
- Ocean acidification—the other major side effect of CO2 emissions besides global warming—is causing countless die-offs, most famously in corals, the backbone of coral reefs, the most biodiverse ecosystems on earth.
- Fertilizer and pesticides poison the ocean, and when combined with the above factors, they help create "dead zones," nearly oxygen-free patches of ocean where almost nothing can live. According to a 2018 paper published in Science magazine, dead zones make up four times as much of the oceans as they did in 1950.
- We eat the sea's living creatures—which is the number-one cause of their declining numbers. There are rates at which we can supposedly fish sustainably—meaning in such a way that we don't run out—but the fishing industry operates in volumes that meet, or surpass the peak equilibrium rate. (Right now, we're hauling up 90 percent of fish stocks globally, according to the UN.) In other words, we're killing as many fish as we possibly can as a byproduct of our industries, and then on top of that, we're also eating as many as we can.
"Shifting baselines" have to do with everyone's gut-level perception of the natural world. The term refers to our tendency to perceive our own early experiences of ecology as the norm, in contrast to what we see later in life. To explain with a non-oceanic example, my own childhood memories of summers in California's Inland Empire include street gutters choked with thousands of California toads. Twenty years later, those toads are mostly gone—likely decimated by chytrid fungus infections. Their loss leaves me with the false impression that the natural order in Southern California has vanished in a very short time, when actually, the damage humanity has caused here is of much longer duration and much larger in scale than the loss of one species of toad (a species that arguably wasn't "supposed to be there" in the first place). Much more serious losses of biodiversity have been rolling out for centuries, but I don't miss animals like the Southern California kit fox, which went extinct over a century ago, because my own baseline never included them.
Similarly, according to Deutsch, we won't collectively care about the death of all the fish, because when it finally happens, our baselines will have shifted so much that the lack of fish will seem normal.
by Mike Pearl, Vice | Read more:
Image: Cathryn Virginia
