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Three U researchers talking

U researchers Ray Newman, Susan Solarz, and David Andow discuss the need for more study into invasive species. The project they lead is supporting up to 25 Ph.D. students.

Super species

By Martin Moen

From eNews, September 11, 2008

Like Kal-El crash landing his spaceship from Krypton, non-native plants and animals are arriving at our doorstep. And like Superman, some of them have traits--developed in their home environment--that allow them to flourish in their new homes. Unfortunately, the impact of non-native species is anything but a comic book fantasy. Zebra mussels, for example, have now entered the St. Paul water system and likely will increase water costs by clogging pipes and shutting down water supplies. The total cost to the United States of the zebra mussel invasion is estimated at $3.1 billion over the next 10 years. "Unlike climate change and habitat loss, invasive species can go undetected, sometimes even when they are at their most severe," says David Andow, professor of entomology in College of Food, Agricultural, and Natural Resource Sciences (CFANS). "It requires a trained eye to identify an invasive insect or plant."

Invasive species are organisms whose superior abilities enable them to out-compete other species in the race for nutrients and reproduction. They have been introduced by accident or on purpose. Scientists estimate there are more than 125 non-native invasive species in Minnesota. And those are the ones we know about.

Exotics, aliens, non-natives ...

Here is a sampling of non-native wildlife and plants:

Carp: Invasive Asian carp have made the news because they can leap out of the water when disturbed by watercraft. (Leaping fish have injured boaters and jet-skiers.) The fish can reach 110 pounds and they feed voraciously on plankton, eating 40 to 60 percent of their body weight each day, which leaves less food for native fish species.

Reed canary grass: Although reed canary grass is planted as a forage crop in some areas, it poses problems in restored wetlands because the grass can dominate the area. Reed canary grass is also limiting forest regeneration across extensive areas of the Upper Mississippi River and Minnesota River floodplains.

Emerald ash borer: The emerald ash borer can kill all sizes and species of ash trees, including green, black, and white ash, within three years. Larvae live under the bark until they emerge as adult beetles. (The tunneling of the larvae under the tree's bark kills it.)

"We should worry about invasive species to the same extent that we care about habitat loss and global warming because, together, they are the triple-threat to biodiversity and the health of our planet," says U alum Susan Solarz, who is coordinating a new University of Minnesota program in invasive species.

If that sounds a bit defensive, it is. The scientists and resource managers involved in controlling these invaders feel the invasive species problem is overlooked. One example of this is the inconsistent reaction to the threat they pose. For instance, wood-cargo crates are inspected before entry to the United States to prevent the introduction of various tree pests, yet the crates' contents, including wood products, are not inspected. "Our policies remain a sieve to invasive species introduction," says Ray Newman, an aquatic ecologist in CFANS. "Minnesota needs a comprehensive approach to invasive-species prevention and management."

Newman believes piecemeal, species-specific approaches must be complemented with broader strategies and better predictive models that address multiple species and pathways and can anticipate future problems. Newman, Andow, and Solarz are part of a team that's attempting to assemble a more comprehensive approach. Their team of more than 40 faculty members in 16 departments throughout the University is conducting invasive species research in many areas, including the economic tradeoffs of prevention and control, the evolution of invasiveness, the modeling of species spread and potential impacts, developing control strategies, and restoring ecosystems after successful control. A $3 million grant from the National Science Foundation will train up to 25 Ph.D. students to better assess, predict, and manage risks of invasive species. "We are listening to what information agencies need in order to best prevent and control invasives and then targeting our research accordingly," Newman says. "In this way, as a team, we will combat invasive species most effectively."

To learn more about the new invasive species project, see "Graduate Training in Risk Analysis for Introduced Species and Genotypes" .