BUENOS AIRES, ARGENTINA — Low water levels on the Parana River in Argentina are forcing grain exporters to reduce the size of their cargo, according to a July 15 report from Reuters.

Dryness in Brazil, where the Parana River originates, has caused a delay in the movement of thousands of tonnes of grain, Reuters reported.

The river transports about 80% of Argentina’s agricultural exports into the Atlantic Ocean. July is among the busiest months for shipping corn and soybeans in Argentina.

Environmental groups told Reuters they are concerned about the impact of dredging the river below a certain depth. The water level is already more than 5 feet lower than normal sailing draft, Guillermo Wade, manager of Argentina’s Chamber of Port and Maritime Activities, told Reuters.

He noted that Handymax and Panamax ships are carrying about 10,000 fewer tonnes than normal to prevent ships for getting weighed down and stuck on the river bottom.

Argentina is the world’s No. 1 exporter of soymeal used for animal feed and is the third largest exporter of corn.