Oil started spilling from the Lizama 158 oil field in early March and spread down 15 miles of the Lizama river and 12.4 miles of the Sogamoso river.
According to local media, it took Colombia's state oil company Ecopetrol three weeks to respond to the environmental disaster.
Colombia Reports noted that the crude started escaping the oil field on March 3 but it was only this past Saturday that Ecopetrol vowed to send heavy equipment that could stop the spill.
The company said Tuesday that the spill is fully controlled and workers are carrying out environmental monitoring of the rivers. The cause of the spill is currently unclear but an investigation is underway.
In addition to the 2,400 animals who died, Claudia Gonzalez, director of the National Agency of Environmental Licenses (ANLA) told RCN Radio that 1,300 animals were rescued alive.
About 1,080 trees of different species were also affected by the spill and about 70 people had to be relocated from the area, with some people reporting health problems.
"I have practically nothing to eat, we have lived through the river all our lives and the contamination has already reached the Magdalena," area residet Elkin Cala told the Colombian television station Noticias Uno.
Barrancabermeja, located off the shore of the Magdalena river in the department of Santander, is home to the largest oil refinery in the South American country.
Santander Governor Didier Tavera Amado has
criticized the oil company for being incompetent and incapable of responding to the environmental emergency.
The move comes after regional authorities declared a state of emergency over the weekend after sightings of more than 50 bears in the town of Belushya Guba since December.
This year's letter from Bill and Melinda Gates focused on nine things that surprised them. For the Microsoft-cofounder, one thing he was surprised to learn was the massive amount of new buildings the planet should expect in the coming decades due to urban population growth.
"The number of buildings in the world is going to double by 2060. It's like we're going to build a new New York City every month for the next 40 years," he said.