An area of the Coeur d’Alene River basin is contaminated with lead and heavy metals from a century of mining waste that has traveled downstream from the Silver Valley. Lead contamination poses a risk to migratory birds in the area. Tundra Swans, for instance, can suffer intestinal, kidney, and reproductive issues.
Now a collaborative effort is underway to measure where the swans are exposed to contaminated sediment, and if their lead exposure is decreasing.
"That is useful because we can either sample within a wetland, and really understand swan exposure to that wetland, or we can sample more broadly and pool together to understand basin-wide trends," said Mark Jankowski, a toxicologist with the Environmental Protection Agency.
Chip Corsi of the Idaho Department of Fish and Game said the concern is not just for the swans, but other animals affected by heavy metals.
“Those animals, when they become diseased or sick, are readily preyed upon by other animals, so those move through the food chain,” Corsi said.
The Coeur d’Alene tribe is also involved in the study, in part because of the importance of the swan to their culture. The tribe’s restoration coordinator, Rebecca Stevens, said the birds actually help proliferate an important tribal food, the water potato.
“And so as they feed on water potatoes, they're actually helping to disperse those water potatoes, which are very culturally significant to the Coeur d Alene people,” Stevens said.
Sampling of the swans is ongoing this week, but the results are not expected to for several months.
