MYTHS OF THE ALIENS - The New Wild: Why Invasive Species will be Natures Salvation - page 75

made by people with no pets. And if cat owners were hospitalized, they left the hospital sooner. Singling
out the bird-eating skills of the alien cat as the only measure of its economic activity seems perverse. 45
Most valuable aliens get left out of Pimentel's calculations altogether. There is nothing on the credit
side for the European honeybee, which the US government estimates carries out pollinating duties worth
$20 billion a year, or for the food value of introduced fish in rivers, the hunting fees garnered from for-
eign game, or the soil-binding power of introduced plants. The huge economic value of introduced crops
is also ignored. Pimentel does say: “We recognize that nearly all our crop and livestock species are alien
and have proven essential to the viability of our agriculture and economy.” But he adds that “this does
not diminish the enormous negative impacts of other non-indigenous species.” 46 Maybe not, but it does
seem odd to include among these negative impacts the billions of dollars spent on pesticides to protect
one set of alien species from another—including no less than a billion dollars for controlling weeds on
the alien greens and fairways of golf courses. And so on.
It may be unfair to single out Pimentel and his shaky statistics. He had a first stab at an important
issue. He should be commended for trying, but that was more than a decade ago. The real scandal is
that everyone, from the UN's top environmental scientists down, keeps quoting his figures. Nobody has
attempted to replicate or better them. This represents a failure of science. If, as many continue to claim,
alien species are the second most important threat to the planet's biodiversity, is it too much to ask that
someone else have a go at costing them? Why has no UN agency commissioned a follow-up? Do they
just like the existing stats too much? In journalism, cynical hacks sometimes recite the tired dictum that
“some stories are just too good to check.” It is distressing to conclude that the global science community
sometimes works by the same standards.
Scientists, starting with Elton, should take considerable responsibility for building public sentiment
against anything alien and for giving respectability to some unpleasantly xenophobic language on the
issue from environmental groups, as well as ill-considered legislation designed to keep alien species at
bay. Invasion biology has taken as a fact that alien species are an almost universally bad thing, dam-
aging nature, degrading ecosystems, and diminishing biodiversity. It has generated UN treaties, such
as the Convention on Biological Diversity, agreed to at the Earth Summit in Rio in 1992, which lists
the “prevention, control and eradication” of harmful invasive species as a core target. Partly to pursue
that agenda, a UN conference in 1996 set up the Global Invasive Species Programme, with a mission
to “conserve biodiversity and sustain human livelihoods by minimizing the spread and impact of invas-
ive alien species.” 47 National governments, including the United States and the United Kingdom, have
widely followed suit, although the global program was shut in 2011 for lack of funds.
As we have seen, there is a backlash among many ecologists against this dogma. They say that the
whole idea of invasion biology as a distinct discipline is founded on a false premise and obscures more
than it reveals. They would do away with it. 48 But instead it seems to go from strength to strength. When
in 2011 the journal Science carried a series of articles quoting ecologists who questioned the pervasive
fear of invasive species, a full suite of heavy-hitting conservation leaders wrote in reply. They warned
that such talk “risks trivializing the global action that is needed to address one of the most severe and
fastest growing threats to biological diversity.” Among the signatories were the heads of WWF Interna-
tional, the IUCN, Conservation International, Birdlife International, and the Wildlife Conservation So-
ciety. Of the leading groups, only the Nature Conservancy—perhaps under the influence of its heretical
science director, Peter Kareiva, of whom more later—ducked out of this political crusade. The conser-
vationists' letter to the world's leading science journal concluded imperiously: “Now more than ever,
academics should be supporting action against invasive species.” 49