The snow had
melted, the sun was shining and the river beckoned, so I took a long walk by
the water this weekend. Being outside was satisfying enough, but I got an
unexpected treat: frogs.
I heard them
first, croaking a chorus in shallow water, then was rewarded with a glimpse as
one swam away. The daffodils haven’t bloomed yet, but the frogs told me spring
is coming. It’s a scene that has delighted children and adults across America
But what if
next year, they’re gone?
and other amphibians are disappearing around the world at an alarming rate and
scientists are trying to figure out why. A recent study points to at least one
have known for more than a decade that pesticides poison frogs, in some cases
giving male frogs female parts. But a study published in the journal
Scientific Reports this January shows that pesticides kill them too.
sprayed European common frogs with six formulations of chemicals regularly used
on crops around the world, at the same doses utilized on fields. They even used
the same kind of sprayer that commercial growers use. One pesticide killed all
the frogs within one hour. Another killed them all within a week. In fact, all
the common, currently used pesticides tested were deadly: A single spraying by
each killed at least 40 percent of all frogs within a week.
If you ever
caught a frog as a kid, or still catch them with your own kids today, you can
easily understand why this happens. That slimy skin is permeable—frogs and
other amphibians breathe through it. Air and water easily pass through it too.
So whatever chemical pesticides get washed into a water body where amphibians
live or breed, seeps inside their bodies.
1,800 species of amphibians (frogs, toads, salamanders and their relatives) are
now threatened or endangered—a third of all those on the planet, according to
the International Union for the Conservation of Nature. More than a hundred
species have vanished in the wild and at least nine have gone extinct since
1980. In some places, their forest and wetland habitats have been destroyed. In
other places, people collect them for food. And as the climate changes
globally, it warms and alters waters where amphibians breed, contributing to
Fish and Wildlife Service has listed 26 amphibian species threatened or
endangered across the nation, in California, Arizona, Arkansas, Florida,
Georgia, Mississippi, Missouri, Nevada, New Mexico, Puerto Rico, South
Carolina, Texas, Virginia, West Virginia and Wyoming.
sensitive, permeable skin of frogs and toads makes them early indicators of
toxins in the environment that could harm other living things—including people.
Amphibians also eat harmful insects, the reason farmers use pesticides in the
first place. So it doesn’t make much sense to kill them off, especially when so
much food can be grown organically and without pesticides.
U.S. and Canadian researchers reviewed dozens of scientific studies comparing
organic and conventional food crops (grown with artificial pesticides and
fertilizers), and reported their findings in the scientific journal Nature.
They found that overall, crops grown with organic methods produce about
three-fourths as much food as conventional methods using pesticides. Some
organic crops, such as fruits, can yield nearly as much food as conventional
techniques. Not bad when you consider all the frog lives saved, and all the
insects they’ll eat. Additionally, the soil on organic farms holds water better
than conventional farms; something worth considering as climate change worsens
drought across the West, Midwest, and South.
something to think about this year when planting a garden or maintaining your
lawn—can you do without chemical pesticides and fertilizers?
More than 50
years ago in her bestselling book, Silent Spring, biologist Rachel
Carson warned of a spring with no bird song because of toxic DDT. Today’s scientists
raise another question: will there soon be a springtime without spring peepers?
Mathews Amos is an independent environmental consultant and a regular columnist
for Blue Ridge Press.