What are they and where do they live?
Leeches are segmented worms that are closely related to the friendly neighborhood earthworm. They are largely aquatic, and many species of leeches live in freshwater environments. They are well adapted to live in the warm waters of lakes, ponds and slow-moving streams. Leeches prefer shallow waters that are calm and tend to live on the bottom in the sediment—they will often attach to rocks or live under leaves or other debris for safety.
Lake leeches are widely present in Georgia’s lakes and ponds. You can find leeches in both Lake Allatoona and Lake Lanier, among other local freshwater swimming spots. In fact, they are a very common lake resident, and they are not a cause for concern.
Are they dangerous?
Not at all! Lake leeches are often carnivorous predators feeding on invertebrate hosts as well as fish and other small mammals, and they generally prefer them over humans as a food source. They are also called “blood suckers”, which sounds menacing, but not all leeches suck blood. Even when they attach to a human host, they don’t transmit diseases and don’t suck enough blood to be harmful.
They are also an important part of aquatic food chains and food webs, because they are a food source for animals such as fish, ducks, crayfish and turtles.
Should we try to get rid of them?
No. Disrupting a food web is never a good idea, unless the targeted species is invasive and causes more harm to the ecosystem than removing them would. Trying to treat the leeches chemically would cause damage to the animals and plants in the ecosystem, and that can have far reaching consequences on the food web. It could disrupt the balance of the entire ecosystem, including the dissolved oxygen in the water and food sources for the animals that live there. This type of damage could last for years after the chemical treatment, and the ecosystem might never recover.
Leeches can be lucky!
Leeches have been used for generations in medicine. Bloodletting used to be a common medical practice, and the little bloodsuckers were used to release blood in patients. Bloodletting is not a common medical practice now but is still used for the treatment of certain blood disorders— especially when the patient has an excess of blood cells which can cause too much iron to be in the blood.
On rare occasions, leeches are still used in modern medicine. They have been used with success in situations where doctors have had to re-attach a fingertip or even a scalp—the leech can remove the excess blood so that it doesn’t pool at the re-attachment site.
Lake leeches are harmless worm relatives—a minor nuisance at most. If one even hitches a ride, wait for the leech to fall off on its own or apply salt or heat to the leech (pulling it off can cause the mouthparts to be left behind and cause infection), clean and bandage the site as you would any other cut. If there are any signs of infection, please see a doctor.
