DETROIT — An oil barge that sank on western Lake Erie in 1937 and was only discovered last August is apparently leaking oil into the lake.

While the potential volume of oil products involved wouldn’t cause an ecological calamity on the Great Lakes, the fact that odors are present at the water’s surface near the wreck could leave boaters in the area inhaling harmful, irritating vapors.

The U.S. Coast Guard on Tuesday continued its response to the shipwreck site – about 3 nautical miles east of Kelleys Island, near Sandusky, Ohio – after a diving club out of Cleveland examining the shipwreck last Friday reported the strong smell of a solvent and discoloration in the water.

An overflight of the area out of the Coast Guard’s Air Station Detroit on Saturday found a “400-yard discoloration in the water near the site,” Coast Guard Petty Officer 3rd Class Christopher Yaw said. Coast Guard boats responding out of Marblehead, Ohio, “also noticed a strong smell of solvent,” he said.

Divers from an environmental response company contracted by the Coast Guard, T&T Salvage, were at the scene Tuesday. “They are trying to identify and secure any leak, if there is one,” Yaw said.

The barge, named the Argo, was discovered Aug. 28 in about 50 feet of water by divers from Cleveland Underwater Explorers, or CLUE, a nonprofit corporation including divers, historians and archaeologists dedicated to finding and recording Great Lakes shipwrecks. At the time, the group was searching for a shipwrecked 1840s schooner, said Christopher Gillcrist, executive director of The Great Lakes Historical Society’s National Museum of the Great Lakes.

On Friday, as the CLUE divers were back at the barge, measuring its dimensions in an effort to further confirm it is the Argo, members on boats at the surface began noticing something unusual.

“Every once in a while … we would get a smell of something in the air,” said CLUE diver Tom Kowalczk. “After it happened several times, I happened to notice there was a little spot of sheen, out to maybe a foot diameter circle, like when you spill oil onto the water.”