The area above Head of Passes was deemed to be safe for navigation, The (New Orleans) Times-Picayune reported.
"Survey operations are ongoing in an effort to locate the sunken 48-foot tug boat C-Pec between mile marker eight and Head of Passes," the Coast Guard said in a release.
The Coast Guard said it was still trying to determine why the tug capsized and sank Saturday, the newspaper said. Two people aboard the tug were rescued.
The closure created a bottleneck for dozens of cargo and other vessels heading up and down the river.