Is modern agriculture’s toxic
hold on nature becoming a death grip?
By Larry Powell
This summer, the tragedy of dying
pollinators took on a new dimension. A team of Dutch researchers found that, in addition to bees, “significant declines in populations of insect-eating
birds are also associated with high concentrations of neonicotinoids.”
Another insectivorous species in decline, the purple
martin. Are they becoming "neonic" victims, too?
PinP photo.
“Neonics,” as they are commonly called,
have become the most widely used group of insecticides in the world – and, the
most infamous. As well as killing the crop pests they are supposed to, they’ve
been implicated in the deaths of billions of honeybees from near and far, for
well over a decade. The European Union even clamped a two-year moratorium on
their use, last year.
Various formulations of the chemical
are made by multinational corporations like Bayer CropScience, Syngenta and
Monsanto. They’re used as seed dressing on crops ranging from canola, soya and
corn, to potatoes. They are “systemic” poisons. That means they penetrate all
part of the plant, even the nectar and pollen. But as little as 2 percent of the plant takes
up the active ingredient. The rest gets washed off,
contaminating both soil and water. “Neonic” use exploded onto the farm scene
about two decades ago, on crops that now cover vast areas of the world’s
farmlands.
The study, by scientists at Radboud
University, was published in the journal, Nature. It concludes, the most
widely-used “neonic,” imadacloprid, poisons not only insects harmful to the
crops, but others which form an important part of the birds’ diets, especially
during breeding season and while raising their young. These would include
grasshoppers, butterfly caterpillars, mosquitoes, midges and mayflies (an
important food source for fish, as well as birds).
“In the Netherlands, local (bird)
populations were significantly more negative in areas with high surface-water
concentrations of imadacloprid. In those cases, bird numbers tended to decline
some 3.5% per year. (This would translate into a staggering loss of about 35%
in a decade!) These declines appeared only after the introduction of
imadacloprid to the Netherlands in the mid ‘90s. Our results suggest the impact
of neonicotinoids on the natural environment is even more substantial than has
recently been reported and is reminiscent of the effects of persistent
insecticides in the past.”
This is an apparent reference to DDT,another persistent insecticide. It was banned in North America after Rachel
Carson’s book, “Silent Spring,” exposed it in the 60s for the mass die-offs of
both birds and fish on the continent. She also revealed its widespread and
dangerous presence in various human organs.
Birds are much less vulnerable to
neonics than insects. So, it is believed avian numbers are declining, not
because of direct poisoning, but because the chemicals are killing off the
insects they normally eat.
“A
route to direct mortality.”
But, it’s also unlikely any bird that
directly eats seed treated with “neonics” will stand a chance. One study
concludes, “A single corn seed can kill a songbird.” Another finds, “Consumption of
small numbers of dressed seeds offers a route to direct mortality in birds.”
And some of the bird species included in the Dutch study, like starlings and
skylarks, eat grain as well as insects.
Is
this just a “faraway” problem? Not really!
(4) Last winter, a biologist at the
University of Saskatchewan sounded a very similar alarm. Christey Morrissey is
about halfway through a four-year study of the chemical in question. She told
the CBC, “Huge amounts of “neonics” are leaching into the millions of potholes
that dot the landscape of the Canadian prairies. This can have potentially
devastating impacts on aquatic insects such as mosquitoes and midges, both
important food sources for birds. She says levels of the poison in the water
have been found to be anywhere from ten to a hundred times above limits which
are considered safe!
Meanwhile, she notes, populations of
insectivorous birds such as barn swallows, have plummeted some 70 percent over
the past 30 years. She concedes other factors, like habitat loss, are
contributing to the decline, too. But she still believes neonics are playing
a significant role.
The Dutch study team suggests, “Future
legislation should take into account the potential cascading effects of
neonicotinoids on ecosystems.”
Ms. Morrissey offered this observation
to the CBC.
“We all want to have food that we
consume and enjoy. But, at what cost? Is that the cost of having no more birds
around? Of having no more butterflies? Having no bees? People are thinking
about that now.”
