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BOB HIRSHON (host):
The pros of parasites. I’m Bob Hirshon and this is Science Update.
In people, parasites aren’t exactly a sign of good health. But in an ecosystem, a thriving parasite population can be a very positive symptom. Marine ecologist Kevin Lafferty of the U-S Geological Survey and his colleagues study parasitic worms called trematodes that live in salt marshes and wetlands. During their lifecycles, the trematodes move between many different animals, including fish, birds, and snails. If any one of those host animals disappears from the ecosystem, the parasites will also disappear.
KEVIN LAFFERTY(U-S Geological Survey):
So when we go to an ecosystem that has a rich, diverse set of animals living in it, we expect to find many different parasites being able to take advantage of that opportunity.
HIRSHON:
Lafferty says this makes parasites an easily accessible window into an ecosystem’s health.
I’m Bob Hirshon, for AAAS, the science society.