Officials announced on Friday that workers have managed to plug all the fuel valves and vents on the dredge that had been leaking oil into Lake Huron since it sank on Thursday morning. According to a report by the Associated Press, the dredge and the tug that had been pushing it, which overturned when the larger vessel sank, were carrying about 1,500 gallons of diesel fuel.
The Coast Guard is not yet certain just how much of the fuel spilled into Lake Huron before workers were able to plug the valves. Both vessels, the 110-foot dredging barge Arthur J and the 38-foot tug Madison, are currently sitting partially submerged in 22 feet of water about a mile from the Michigan shoreline.
Here is some of the key information regarding the potential environmental impact of the vessels' sinking.
* No injuries from the vessels' accident were reported. There are no known cases of affected wildlife as of yet.
* The Coast Guard has said that fuel from the vessels has reached the Michigan shoreline at Lakeport State Beach. Other area beaches were closed due to reports that diesel could be smelled in the vicinity.
* Workers had trouble closing the valves immediately after the vessels sank on Thursday because of stormy weather, which saw crews battling against winds that were between 15 and 20 knots, as well as heavy rain and choppy waters, according to the Detroit News.
* Crews had quickly placed 800 feet of absorbent boom around the vessels to try and prevent the fuel from spreading. Even so, an area of one mile by two miles in Lake Huron reportedly had a sheen of diesel fuel as of Thursday night. Later on Thursday the sheen had reached the Lakeport State Beach area.
* Darwin "Joe" McCoy, who owns MCM Marine in Sault Ste. Marie, the company that owns and operates the two vessels, told the Detroit News on Friday that he did not believe that the sinking was caused by human error. He speculated that the problem had instead been the height of the water on Thursday, saying "Most hydraulic dredges of this size are susceptible to waves larger than 4 or 5 feet."
* Lauren Laughlin, a public relations spokeswoman for the U.S. Coast Guard, told MLive on Friday that the bad weather that prevented workers from closing the valves had actually in some ways been beneficial, because it prevented the sheen of diesel fuel from blocking sunlight getting through the water to the plants and fish below.
* MLive also reported that the initial 800 feet of absorbent boom had been expanded to 1,400 feet by Friday.
* The environmental impact of the spill is expected to be minimal, due in large part to the actions of the crew of the ship Drummond Islander II, which was pulling both vessels. The crew worked to move oil and secure tanks after it became obvious that the dredge was taking on water, minimizing the amount of fuel that could flow into the lake, according to the Detroit News.
Vanessa Evans is a musician and freelance writer based in Michigan, with a lifelong interest in politics and public issues.