Stopping the Invasions
By Kathleen Schmitt
October 10, 2001
In the fight against invasive species, an ounce of prevention
is much cheaper than a pound of cure.
Our forests, grasslands, and waterways are becoming polluted
with animals and plants. These are invasive species that
can drive out the organisms that are native. Many people
are trying to fight these alien species after they settle
in, but one ecologist says we should focus more on preventing
these invasions from ever happening.
David Lodge is an ecologist at the University of Notre
Dame. He says invasive species are leaving a lasting mark
on the Earth.
"When ecologists survey on a global scale what
factors are most important in the extinction of native
species worldwide, what they see is that nonindigenous
or alien species are one of the most and sometimes the
most important cause of extinction native species."
Lodge says many invasions can be prevented before the
plant or animal becomes established in its new home. But
he says most researchers and natural resource managers
don't deal with the invaders until after they've become
a problem. Lodge says it's rare to find an effective way
to control invasive species. The approach to the foreign
sea lamprey in the Great Lakes is often noted as an exception.
People use chemicals to kill young sea lamprey and set
up barriers to prevent the adults from spawning. Lodge
says many people see this as a success story, but it's
an expensive one.
"That success story costs Canada and the United
States 14 million dollars every year. And that, we feel
is a success. So surely it would be much more cost effective
for society to spend some resources up front preventing
things like sea lamprey from getting established, so that
we aren't saddled with paying for controlling them in
perpetuity in the rare cases when we can actually figure
out how to do that."
Lodge spoke at this year's meeting of the Ecological
Society of America.