Saying the Mississippi River Gulf Outlet has destroyed large parts of Louisiana's coastline and contributed to the devastating damage New Orleans suffered during Hurricane Katrina, a coalition of environmental scholars and advocates this week released a report calling for the shipping canal's closure.

Titled "Mister Go Must Go: A Guide for the Army Corps' Congressionally-Directed Closure of the Mississippi River Gulf Outlet," the report was released 10 days before the U.S. Army Corps of Engineers' Dec. 15 deadline to present Congress with a plan for closing the channel to oceangoing ships and possibly to all water traffic. It was written by John Day, a Louisiana State University professor emeritus of oceanography and coastal sciences; Mark Ford of the Coalition to Restore Coastal Louisiana; Paul Kemp of LSU's Hurricane Center; and John Lopez of the Lake Pontchartrain Basin Foundation.

"Closing the deadly MRGO and fixing the damage it caused is a win-win situation for both American taxpayers and Gulf Coast residents," says Paul Harrison, coastal Louisiana project manager at Environmental Defense, which endorsed the report. "MRGO remains an enormous physical danger for New Orleans, has degraded its environment, and cost the American taxpayer as much as $45 million each year to maintain, yet it is used by fewer than 10 ships a day."

The corps created MRGO by cutting through the natural land bridge and barrier islands that separated New Orleans from the Gulf. The structure allowed saltwater to flow into the area's freshwater bayous and lakes, killing tens of thousands of acres of cypress forest and wetlands that served as a natural hurricane barrier. It also acted like a funnel, accelerating the rate at which tropical storms spun toward New Orleans. In the case of Katrina, the amplified storm surge put unprecedented strain on manmade levees, contributing to their failure.

"Closing MRGO and restoring the natural ridges and wetlands that used to protect New Orleans and St. Bernard Parish is a litmus test of whether the Army Corps and Congress are serious about protecting the New Orleans area from hurricanes," says Melissa Samet, senior director for water resources at American Rivers.

Among the other organizations and individuals that endorsed the report are the National Wildlife Federation, Gulf Restoration Network, Louisiana Wildlife Federation and St. Bernard Parish President Henry "Junior" Rodriguez.