A dead dolphin found in the Hutchinson River in Mount Vernon has raised questions about water pollution.

Officials say the dolphin was found Friday afternoon, and the state Department of Environment Conservation was called to the scene. Experts say it is likely the marine mammal traveled upstream from the Long Island Sound and died.

The Environmental Protection Agency ordered Mount Vernon to stop raw sewage leaks from contaminating the river. However, repairs to the sewage system weren't approved by the city council.

“The dead dolphin is a somber reminder of what pollution can do to our environment and to our sea animals,” says Mount Vernon Mayor Richard Thomas. “Mount Vernon has an obligation and a requirement to clean up the Hutch and we must get on with that now.”

City Councilman Marcus Griffiths says Thomas doesn’t have a plan, and that the mayor needs to fix the sewer line where there is contamination going into the Hutchinson River.  He says it’s been going on for a year.

The DEC is performing a necropsy on the dolphin to determine what killed the dolphin.