Study: Avoiding predators has its price

clipped from www.mlive.com TRAVERSE CITY, Mich. (AP) — It hardly seems fair, but water creatures nimble enough to avoid being gobbled up by predators might harm their species more than help, new research suggests. Fish, amphibians and even tiny zooplankton do many things to escape hungry enemies, from finding new homes to changing their physical characteristics. Such tactics may save individual lives — but in the long run might leave the population worse off, Michigan State University scientists say. "When you introduce a predator into a system ... the potential prey don't sit around and say, `Eat me,'" fisheries biologist Scott Pecor said. "They have adapted to get out of the way. But that comes at a cost." Though the study focused on two particular species in the Great Lakes, it has implications for other predator-prey relationships, At least 183 such species have been detected in the lakes. Most apparently were carried across the ocean in ballast tanks of freighter ships.