The Coast Guard is responding to a sunken towing vessel in Pass a Loutre near Venice.
Three people were aboard the Dejeanne Maria when it began to sink at around 2 a.m., and were rescued by another towing vessel, the Coast Guard says.
The towboat was pushing two empty dry cargo barges downriver on the Mississippi when it hit an object underwater, the Coast Guard said.
An assist tug is en route to retrieve the barges, the Coast Guard said.
The Dejeanne Maria is submerged with its port side above the water. It is not blocking the channel.
There is a maximum potential of 7,000 gallons of oil on board with a reported 60 gallons having entered the water.
Sector New Orleans incident management team mobilized to conduct a shoreline assessment. ES&H was contracted to respond and deployed boom around the sunken vessel. An ES&H air drone and Coast Guard overflight observed no active discharge of oil.
The incident is under investigation.