Parasite kills swans at Wolf Lake; cause of death in geese remains unknown, DNR says
Mary Freda May 10, 2021
Dead waterfowl were found earlier this spring in the northern portion of Wolf Lake in Hammond.
HAMMOND — Officials have somewhat determined the cause of death for waterfowl found at Wolf Lake earlier this year.
Officials warned the public in early March to avoid the lake after dozens of dead waterfowl, including geese, ducks and swans, were reported in the area, according to a previous Times report.
In wake of the deaths, Hammond Mayor Thomas McDermott Jr. said testing conducted by the city showed neither the soil, nor the water at Wolf Lake caused the waterfowl to die, a previous Times report states.
In a press release Monday, the Indiana Department of Natural Resources (DNR) said testing completed by the U.S. Geological Survey’s (USGS) National Wildlife Health Center in Madison, Wisconsin, found the presence of parasitic flat worms in wild swans from Wolf Lake.
The mute swans had fatal infections from an intestinal parasite that causes death in various species of waterfowl, including swans, diving ducks and coots, DNR said.
Lead testing also was performed on the swans, and results were within the range of non-toxic background levels, DNR said.
The parasite doesn't pose a known risk to humans, pets or the commercial poultry industry, DNR said, noting snails eaten by the swans and other waterfowl are an intermediate host for the parasite.
"Infected birds may appear weak or unable to fly and often die. Control measures have not been developed for this parasite, and waterfowl deaths may recur on a regular basis," DNR said.
A cause of death could not be determined, despite "extensive testing," for the Canada geese also collected from Wolf Lake.
The geese tested negative for bacterial and viral infection, lead poisoning, heavy metals, salt toxicity, botulism and toxic organic compounds, DNR said.
Both the swans and the geese tested negative for bird flu.
"Wildlife disease investigations can be challenging, especially when multiple factors, including adverse weather conditions, may be involved," USGS scientist Julia Lankton said in a press release.
"While we could not confirm a cause of mortality for the Canada geese, we are glad that the mortality event seems to have resolved and dead birds are no longer being reported."
The DNR said in a news release the deaths of the Canada geese declined in early March after reaching peak mortality for about a week in late February after severe cold weather.
Mute swan deaths were not observed until early March, DNR said.
“The DNR, together with state, federal and private partners, has been monitoring migratory bird populations in the area and mortality seems to have subsided,” Mitch Marcus, fish & wildlife health supervisor for the Indiana DNR Division of Fish & Wildlife, said in a press release.
Animals that are ill, or suspected to be sick, should not be consumed, the DNR said.
The DNR encouraged anyone who sees ill or dead wildlife to report it at on.IN.gov/sickwildlife.
From
www.nwitimes.com/news/local/parasite-kil...1a-afee63b29c54.html 
