Commentary by Roger Martin Martin writes about research at KU for Kansas media and in a Web zine. Contact Martin at rmartin@kucr.ukans.edu or (785) 864-7239. Martin also can be heard on KANU 91.5 FM public radio Archives More articles by Roger Martin Subscribe now to receive KU News by email

Species that bully

by Roger Martin

From time to time, exotic species break loose inside our borders and start bullying their way around.

The kudzu vine carpets every green thing in its path. Carp from Europe dominate in places where native buffalofish once swam. Starlings and house sparrows shove other birds out of the way.

And now here comes the snakehead fish. From the Yellow River region of China, it has made its way to a pond in Maryland -- just 20 short miles from Washington, D.C.

A nasty member of the finny tribe, it can grow a yard long. Has pointed teeth. Eats other fish, ducks, whatever. Reproduces like crazy.

Can live on land two or three days, breathing by virtue of capillaries in its mouth. Wiggles across the terrain on its fins. May eat small mammals along the way. The secretary of the interior has called this Frankenfish "something from a bad horror movie."

A University of Kansas ichthyologist, Ed Wiley, is under contract to map how far west the snakehead could spread. It's one of about 20 temperate-climate Asian and European species Wiley is studying.

For each, he's constructing maps that show where they might find life bearable. Could the snakehead make it in Kansas? Wiley said that the species found in Maryland could survive in most of Kansas.

That's an extremely preliminary finding based on a quick and dirty analysis performed by Lifemapper, a species mapping project at the KU Biodiversity Research Center.

Wiley is early in his threat assessment of the temperate-climate fishes. He's doing the work for the U.S. Geological Survey with funds from the Florida Caribbean Science Center. He'll also be predicting the habitat range of the zander, the European equivalent of our walleye; the European catfish, which can attain a size of several hundred pounds; and the black carp, which is captive today but inevitably won't be, Wiley said.

How does Wiley map the potential range of these species? First, he builds a profile of the habitat the species came from. It includes two dozen to four dozen factors, such as annual rainfall, temperature and elevation.

Then computers identify geographic areas in the United States that match the species' environmental requirements and predict where it might flourish.

Now, please don't grumble about pest species winding up on our fair shores.

After all, the fish most widely scattered across the world by humans is our very own largemouth bass. This bully has found its way into about 100 countries, Wiley said. The Japanese introduced it in the 1930s, he said, and now they'll never eradicate it.

The more recently introduced smallmouth bass -- also ours -- represents a threat to Japanese river salmon.

"We export some pretty bad top predators," Wiley said.

Reporter Andrew Revkin, writing in the New York Times last week, summed things up from a broader perspective. He wrote, "Humans have become a biological blender, carrying West Nile virus to America and overrunning the Bordeaux countryside in France with American bullfrogs that residents say do not even taste good."

For better or worse, being a biological mixmaster is one of the perks that comes with our being the planet's No. 1 predator.

Here's hoping that we'll learn to wear lightly the mantle of authority we so often and so automatically presume is ours.