WATCH: Massive shipload of cattle sinks in piranha-infested Amazon

A Lebanese-flagged ship carrying 5,000 cows sank in the Amazon River this week, spilling 700 tons of diesel fuel into the hemisphere’s longest waterway.

The “Haidar” sank on Tuesday near the Brazilian city of Belem, on the mouth of the Amazon. Brazilian officials are working around the clock to contain a 2 mile long slick of diesel that’s making its way to the Atlantic Ocean.

The cause of the wreck is still unknown. A cellphone video shows the boat capsizing in front of a local port.

Local residents managed to save some of the boat’s bovine cargo, but most of the cows reportedly drowned in the flooded hull of the ship. Others managed to swim out of the boat, but were dragged down by the current of the piranha-infested waters.

Environmental authorities are collecting and burning hundreds of cattle carcasses that have washed up on shore down river, according to Brazilian website UOL.

The Haidar’s tragedy is not only a Brazilian problem. The large load of cattle, owned by Brazilian beef company Minerva, was headed to Venezuela, a country that has been struggling with food shortages -and long lines at supermarkets- for months.

With price controls, expropriations and economic mismanagement decimating Venezuela’s local cattle industry, the South American country has become increasingly dependent on food imports and gets much of its beef from Brazil.

Venezuelan cattle ranchers estimate that the sunken load was worth around $50 million, but the losses should be covered by the shipping company, according to Minerva.

Manuel Rueda is a correspondent for Fusion, covering Mexico and South America. He travels from donkey festivals, to salsa clubs to steamy places with cartel activity.