TRAVERSE CITY, Mich. (AP) — Michigan’s U.S. senators are calling for a ban on shipments of crude oil by vessels on the Great Lakes.

Sens. Gary Peters and Debbie Stabenow introduced legislation Wednesday that would prohibit such shipments. They don’t happen now, but Peters says the idea of using barges or tankers to move oil on the lakes has been raised.

The bill also would require federal studies of risks posed by pipelines that run through the Great Lakes and other waterways in the region. The studies would consider alternatives to an oil pipeline beneath the Straits of Mackinac owned by Enbridge Energy Partners, which is conducting a spill response exercise with government agencies Thursday.

Additional provisions in the measure would require improving spill response plans and giving the public more information about pipeline risks.