By Tom Polansek
CHICAGO (Reuters) - A traffic jam on the lower Mississippi River swelled to 771 barges on Thursday as a fractured bridge near Memphis closed the waterway that is crucial for U.S. crop exports.
The shutdown fueled concerns about shipping U.S. grain and soy to export markets at a time when global inventories are slim and prices are near eight-year highs. U.S. corn futures sank more than 5% in a setback from the lofty prices.
At the spot where the river is closed, 26 vessels with 430 barges are waiting to pass north and 21 vessels with 341 barges are in the queue to go south, said Petty Officer Carlos Galarza, a Coast Guard spokesman.
A day earlier, a total of 411 barges carrying crude oil, dry cargo like crops, and other materials were backed up in both directions.
The Tennessee Department of Transportation must finish investigating the bridge before a decision is made to reopen the river, Galarza said.
Tennessee officials hope to "have a decision for river traffic" in the next day or so, said Nichole Lawrence, a spokeswoman for the state Department of Transportation. She said a timeline has not been determined and the bridge is still under inspection.
The Coast Guard stopped all traffic on the river near Memphis on Tuesday between mile markers 736 and 737 after a fracture was discovered in the Hernando de Soto Bridge that spans the river.
Almost all grain barges must pass beneath the bridge on their way to Gulf of Mexico export facilities near New Orleans after being loaded along the upper Mississippi, Ohio, Illinois or Missouri rivers, according to the Soy Transportation Coalition, an agricultural industry group.
Grain traders said they expect river traffic to resume within days. However, shippers are not booking barges for this week and next week because the closure has left them uncertain barges will be available, barge sources said.
(This story is refiled to correct spelling of Mississippi in headline)