Over forty tons comprising thirteen different species of dead fish are being picked out of the waters of the Rio dos Sinos, just twenty-five kilometres north of the capital city of the state of Rio Grande do Sul, Porto Alegre.

Chemical engineer for the emergency service at the State Foundation for Environmental Protection (FEPAM) Vilson Dutra pointed out that the river is affected by industrial and urban waste from at least thirty districts.

Evidence confirms that the pollutants came down the Arroio Portão, a smaller course of water which is just 16 km long before flowing into the Rio dos Sinos. The Arroio Portão receives effluent from 186 companies.

The dead fish are found in 15 km of the river. Tanneries, rubbish dumps and food factories that discharge their effluents into the Arroio Portão are being inspected but, as the cause has not yet been found, the problem persists and more fish are dying all the time. The problem coincides with the fish mating season and specialists estimate that the thirteen species affected may have been wiped out.

One food producer and two tanneries have been booked in connection with the incident and may be fined R$50 million ($25 million) each.

“We have found irregularities in the operation of the effluent treatment plants of the companies involved. The incorrect operation of the systems has allowed the discharge of materials that are not in line with the standards set by the current environmental legislation”, said biologist Jackson Müller, technical director at FEPAM.