Since millions of gallons of mining waste burst from an inland iron ore mine a month ago, 300 miles of the Rio Doce stretching to the Atlantic Ocean has turned a Martian shade of bright orange, and the deadly consequences for residents and wildlife are just beginning to emerge.

At least 13 people died in the initial flooding, and many in communities along the river have suffered from diarrhea and vomiting as the toxic mud seeped into their water supply.

Eleven of the 90 native fish species in the river were already at risk of extinction prior to the spill, according to federal environmental officials, and experts believe that wide-ranging forms of animal and plant life will be wiped out as entire ecosystems are destroyed.

With Brazil’s level of biodiversity, the die-off is likely to include an untold number of species that have yet to even be discovered.

Several days ago, the toxic sludge, which continues to spew from the mining site, reached the Atlantic Ocean in the city of Linhares north of Rio de Janeiro, as workers undertake a series of emergency projects to mitigate the damage along the river and into the Atlantic.

“There’s never been a disaster like this before, so there’s no guidebook for what we’re supposed to do,” said Rodrigo Paneto, environmental secretary for Linhares, who is overseeing an emergency dam project to protect the city’s water source. “We’re in war mode, just running around responding to dangers as they appear.”

Meanwhile, residents of Linhares, nearby Colatina, and myriad inland communities join long lines to receive bottled water from the military.

Experts say diseases related to water supply issues will likely result in deaths of riverside residents. Authorities, meanwhile, struggle to learn what other types of toxic material have spewed from the broken dam. So far, they know that the mud contains extremely high levels of iron and manganese; dangerous levels of arsenic have also been detected.

Metallic dust from the river is also likely to form, creating airborne safety risks.

“This is a permanent blow. The cost is irreparable. A lot of life forms are never coming back,” said professor Carlos Machado, a researcher who studies natural disasters at the Oswaldo Cruz Foundation in Rio de Janeiro.

There’s no telling how many more might die from long-term public health problems generated by the disaster, he said. “A lot of attention has been paid to those directly affected by the spill. But the risks are much larger than that, and they will last a long time.”

Machado estimates that the surviving ecosystem could take anywhere from 10 to 50 years to regenerate — and what comes back would be different.

The dam near the inland city of Mariana that broke on Nov. 5 is operated by Samarco, a mining company owned by Brazilian mining giant Vale and Anglo-Australian mining giant BHP Billiton.

When the barrier burst, for unknown reasons, more than 60 million cubic meters of waste began flooding nearby communities and wound up in the Rio Doce.

Further investigation of the fault for the dam break is needed, government officials say, but already, Brazil is suing Samarco for at least $5 billion.

The timing couldn’t have been much worse, analysts say. Iron ore is one of Brazil’s most important exports, and the nation is experiencing its worst economic crisis in decades.

Radical changes to mining sector regulations are unlikely, says Joao Augusto de Castro Neves, Latin America Director at the Eurasia Group in Washington, not least because the local governments who oversee mining operations need the revenue. Mariana, a community of 58,000 people in the state of Minas Gerais — which translates to General Mines — has been reliant on mining for centuries. The small neighborhood of Bento Rodrigues was destroyed in the flood.

In written statements, both Vale and BHP Biliton said they would create a “voluntary, nonprofit fund to support the rescue and recuperation of the Rio Doce river system.” The size and scope of the fund have yet to be determined.

As the toxic sludge seeped toward the ocean, residents of hundreds of communities along the river’s banks in Espírito Santo state watched in helpless horror.

Within weeks, the pollution reached the ocean in Linhares. Families here gather daily at the mouth of the river, where experts collect samples for testing, and simply gape at the otherworldly changes.

“We were expecting the mud, so we were preparing, or so we thought,” said Fabio Gama, who organizes kayak expeditions to cocoa-producing islands and is vice president of the residents’ association in the beach fishing community of Regencia, where the waste enters the ocean. “The gravity of the situation only sank in when we saw the river turned into that indescribable red color. And everyone began to cry. They knew they lost their river, they lost their fish, they lost their culture.”

Gama was eating lunch with his family at the restaurant of Sergio Missagia, who was de-waxing his surf boards. No one knows when it will be safe to go back into the ocean.

Assurances from the government and corporations have done little to allay the fears of residents.

“It was like an entire tsunami of mud had come over the world,” said Aline Lata, a filmmaker from Sao Paulo who went to Mariana as a community volunteer and to help document the wreckage. Chaos reigns, she said. “It’s just general confusion. There are families who don’t know if or when they can go home, and others who have nothing to live on.”

In the city of Colatina, an eight-hour drive from Mariana, teenagers sprint through alleyways to join a long line of residents seeking to pick up bottled water off the back of an unmarked truck.

“The authorities and Samarco say that we can drink the water coming out of their river water treatment facility,” says Paulina Prado, 25, who sells sandwiches nearby. “But people are getting sick. And look at that river! Nobody trusts them.”