We
live in the midst of the sixth great Extinction and no one gives a
fuck
Why
scientists are so worried by the huge, sudden loss of insects
A
stunning paper on Puerto Rican insects is just one story in an age of
mass extinction.
Puerto
Rico’s protected rainforests are losing insects — fast. Wolfgang
Kaehler/LightRocket/Getty Images
17
October, 2018
In
Puerto Rico’s rainforest, scientists have observed an astounding
loss of life at the very base of the food web. It’s the insects.
As
an alarming new study in Proceedings of the National Academy of
Sciences outlines, between 1976 and 2013, the number of invertebrates
(like insects, spiders, and centipedes) in the Luquillo rainforest
caught in survey nets plummeted by a factor of four or eight. When
measured by the number caught in sticky traps, invertebrates declined
by a factor of 60. These dramatic drops occurred despite the fact
that the forest is a protected wildlife area.
The
researchers note that this loss of invertebrates — which serve as
food for many other forms of life in the ecosystem — has also
coincided with losses of birds, lizards, and frogs. “The food web
appears to have been obliterated from the bottom,” the Washington
Post’s Ben Guarino reported on the study. Guarino’s story quotes
one invertebrate expert who called the research “hyper alarming.”
The
report is just one example of a larger, troubling trend: Insects —
including yes, bees — and other critters are rapidly disappearing
around the world. A 2017 study in Germany noted a 75 percent decline
in flying insects over three decades. “The widespread insect
biomass decline is alarming,” the authors wrote, “ever more so as
all traps were placed in protected areas that are meant to preserve
ecosystem functions and biodiversity.”
There’s
no one reason why so many critters are dying, and researchers are
still unclear on what’s driving the change. Climate change (and
changing drought and weather conditions) is strongly implicated. And
it’s also partly due to environmental toxins and possibly
pesticides. But it’s fair to say they’re mainly dying because
humans are changing the world for the worse.
Humans
are driving a huge array of species to extinction
A baby monkey is cuddled by its mother to keep warm as the sub-zero temperatures freeze life during a fresh snowfall in Tangmarg. Tauseef Mustafa/AFP/Getty Images The
world is losing biodiversity, fast. If you take stock of all the
studies that point to the fact we’re living in an age of mass
extinction, perhaps even the sixth mass extinction, it can all feel
overwhelming.
Mammals,
the branch of the animal kingdom to which we belong, are also in
peril, another study, also published in PNAS this week, illustrates.
More than 300 mammal species have been wiped out since humans overran
the world after the last ice age (and an additional 25 percent of all
mammals alive today are threatened with extinction). The study asks a
simple question: How many years would it take for evolution to
naturally replace all the species that have died as a result of
humans?
Their
answer: 3-7 million years. Science writer Ed Yong points out “that’s
at least 10 times as long as we have even existed as a species.”
It’s
important to take stock of what we lose when we lose species. A 2017
report in Science Advances found that around 60 percent of primate
species are threatened with extinction — all due to human activity.
The
report found every member of the primate family Hominidae (great
apes, which includes gorillas and chimpanzees) is endangered or
critically threatened (except for us). Around 87 percent of Indriidae
(larger lemurs) are similarly endangered or threatened.
Think
of what that means: Primates are our closest relatives on Earth. If
we can understand them better, we can understand ourselves. Here’s
how Carl Zimmer at the New York Times explains it:
The
first primates evolved roughly 80 million years ago, and then split
into the living lineages over millions of years. By comparing our
biology to those of other primates, we have learned about the
evolution of our brains, our vision and our vulnerability to
diseases.
But
don’t necessarily consider primate losses to be more important, or
painful, than insect losses. Insects and other arthropods form a
hugely important foundation in many ecosystem animal food webs. They
also are the world’s pollinators, ensuring that plants produce new
seeds and new generations. Without the foundation of insects, the
ecosystem collapses.
We
need to take stock of the wildlife we’ve lost
Here’s
one more sobering example of just how many species around the world
are threatened.
The
past few decades have seen a massive die-off of amphibians, which
scientists fear are some of the most vulnerable animals to losses in
a rapidly changing world. That may be because amphibians need both
healthy aquatic and terrestrial environments to thrive. Change just
one enough, and species suffer.
In
2010, a survey of 25,780 species of vertebrates found that 41 percent
of the amphibians were threatened with extinction. “On a
per-species basis, amphibians are in an especially dire situation,
suffering the double jeopardy of exceptionally high levels of threat
coupled with low levels of conservation effort,” the study noted.
Since just 1970, 200 species of frog have perished.
Earlier
this year, researchers, tried to estimate a weight for all of life on
Earth. It was a fun exercise, putting humanity’s relative small
weight on Earth in dramatic contrast to the weight of all the other
forms of life. There are an estimated 550 gigatons of carbon of life
in the world. And we all weigh just .06 gigatons.
If
everyone on the planet were to step on one side of a giant balance
scale, and all the bacteria on Earth were to be placed on the other
side, we’d shoot violently upward. That’s because all the
bacteria on Earth combined are about 1,166 times more massive than
all the humans.
We’re
a small part of the living world, but yet, we make such an outsized
impact on it.
The
authors of the weight estimate were also sure to calculate what was
missing from their figures. They estimated that the mass of wild land
mammals is seven times lower than it was before humans arrived.
Similarly, marine mammals, including whales, are a fifth of the
weight they used to be because we’ve hunted so many to near
extinction.
Although
plants are still the dominant form of life on Earth, the scientists
suspect there used to be approximately twice as many of them —
before humanity started clearing forests to make way for agriculture
and our civilization. Animals are going extinct 1,000 to 10,000
faster than you’d expect if no humans lived on Earth.
Insects
dying off in Puerto Rico may seem like a small — but shocking —
story. What’s all the more alarming is that stories like it are
happening everywhere.
With
so much devastating and widespread loss, it’s hard to say where we
should focus our attention — other than just working to stem the
progression of climate change. In Science, Jonathan Baillie, the
chief scientist at the National Geographic Society, and Ya-Ping
Zhang, the vice president of the Chinese Academy of Sciences, argued
that half of all land should be protected for wildlife by 2050, to
give plants and animals a chance to thrive.
This
is a lofty, perhaps unrealistic goal. But we’ve taken so much from
wildlife. We need to think more about how to stop taking environments
away from plants and animals. “Simply put,” they write in
Science, “there is finite space and energy on the planet, and we
must decide how much of it we’re willing to share.”
Posts
/cdn.vox-cdn.com/uploads/chorus_image/image/61807793/GettyImages_454207082.0.jpg)
:no_upscale()/cdn.vox-cdn.com/uploads/chorus_asset/file/7855801/GettyImages_631966276.jpg)
