MADISON, Wis. (WMTV)-- The Madison Fire Department is asking anglers to stop using lead-based fishing tackles after a tundra swan was poisoned but survived and another swan died after swallowing such tackles on Lake Mendota.
The first incident happened last January, when MFD's Lake Rescue Team was called onto the waters to help a tundra swan that appeared to be stuck on the ice.
But the rescuers soon discovered that the swam wasn't frozen, but sick. Some time later, the swan passed away.
Tests concluded that it had died from lead poisoning, from a fishing tackle stuck in its digestive system.
Then, just last week, the Lake Rescue Team was once again called out onto Lake Mendota to help a second tundra swan, which appeared to be struggling off of the shore.
First responders successfully saved the bird, but when it was tested, lead toxicity readings were off the charts, coming it at 310 ug/dL in the bird's bloodstream.
Levels above 10 ug/dL are considered toxic, according to MFD.
Using a treatment called "chelation," wildlife rehabilitators have begun to remove the lead from the bird's bloodstream. They report that the swan is doing better in their care.
According to rehabilitators, lead-based fishing tackle is likely causing the illness in the swans. Authorities are now calling anglers to consider lead-free fishing products when they are out on the lakes.
"Even the most careful anglers can lose a line or two in the water. For these birds, just a little bit of lead can cause a big, life-threatening problem," according to MFD.