Saving the Leech

They aren't as cuddly as panda bears or as majestic as bald eagles, but leeches have found a champion. The pharmaceutical company Glaxo Wellcome has donated 54,000 pounds ($88,500) toward the well-being of the medicinal leech, a threatened species in the U.K. The money, which will be split over 3 years, will be used to identify existing leech populations and to protect the 20 known populations.

Physicians have used the medicinal leech, Hirudo medicinalis, to reduce swelling, prevent blood clots, and heal bruises for more than 2000 years. The 8-centimeter-long leeches were once abundant throughout freshwater streams and ponds of western Europe, where they fed on blood from amphibians or mammals. But their numbers declined during the mid 1800s, when heavy use by doctors and drainage of wetlands for agriculture wiped out many natural populations. Ignored for most of this century, leeches have enjoyed a recent boost in popularity, thanks to a resurgence of medicinal leech use in neuroscience research and in plastic surgery and finger or toe reattachment. (Doctors use leeches to drain pooled blood until veins can regrow.)

Glaxo announced last month that it would become a "species champion" on behalf of the leech, under the British government's biodiversity action plan. "It's a good fit," says Nancy Pekarek, communications manager at Glaxo Wellcome in Greenford, England. "We are a medical pharmaceutical company, and the leeches have been used medicinally for centuries."

Peter Maitland, a biologist at the Fish Conservation Center near Edinburgh, says that Glaxo Wellcome's money "will let us do quite a bit of useful work." It's not easy to monitor the reclusive leeches, he says, because the animals hide out for many months after feeding. He has been devising ways to keep tabs on the population by counting the number of egg sacs the leeches leave on shore. And he has been reintroducing captive leeches back into the wild.

Posted in Environment