The Brazilian mine disaster that conservationists and engineers have been battling for the last couple of weeks has seen more disasters when toxic mud and iron-ore residue from the BHP Billiton-Vale dam collapse has flowed down to the Rio Doce and into the Atlantic Ocean.

BBC noted that the waste has travelled more than 310 miles and workers have dredged the river mouth to help the mud flow out to sea. The contaminated mud was found to contain toxic substances such as mercury, arsenic, chromium and manganese exceeding human consumption levels, but Samarco insists that the mud is harmless.

Experts say otherwise. The Director of the Marine Biology School in Santa Cruz in Espirito Santo State, Andres Ruchi, said that the mud could have devastating effects when it reaches the sea, considering that near the mouth of the Rio Doce is a feeding ground and breeding location for many marine species including the leatherback turtle, and some dolphins and whales.

"The flow of nutrients in the whole food chain in a third of the south-eastern region of Brazil and half of the Southern Atlantic will be compromised for a minimum of a 100 years," he added.

According to The Guardian, 16 days after the collapse of the dam that supported the reservoir of the Samarco mine, waters in the delicate Rio Doce estuary turned brown --- a disaster for the small village as they depend on fishing, tourism and marine conservation to survive. The toxic mud represents an existential threat to the fewer than 2,000 residents in the area.

Samarco has already erected 9km of temporary floating barriers to try to hold back the mud. At the moth of the river, the company has been using heavy equipment to remove sand banks and dredge to let the mud reach the sea, where it can flow out and be diluted.

Antonio de Padua Almeida, head of the local Comboios nature reserve said, "The best thing that can happen now is for the mud to flow out to sea as quickly as possible. The mud will have much greater impact on the river than on the sea."

It is currently fish and breeding season and locals have been helping fish into tanks and collecting turtle eggs to incubate, in an attempt to save the animals from the toxicity.

To cover costs for the initial cleanup and as compensation for families affected in the dam burst, Samarco, which is owned by mining giants Vale and BHP Billitn, has agreed to pay the Brazilian government $260 million.