Officials are investigating into the oil spill, which has covered dozens of beaches after it was found the oil was not produced in Brazil.
The spill stretches 1,500 kilometers and has affected more than 40 cities. It was first detected on September 2.
'We've never had an accident like this'
According to the BBC, Fernanda Pirillo, Co-ordinator of Ibama (the Brazilian Institute of Environment and Renewable Natural Resources) told Brazilian news outlets: "We've never had an accident like this in Brazil.
"It's the first time we're seeing an accident with an undetermined source affecting so many states."
Instituto Verdeluz, whose mission is 'reconnecting people with nature' posted pictures of a 'tar-toise' after receiving an alert from residents of Serviluz.
"In all, there have already been five strandings, of which we were aware, of tar-tortoises found in September in the state of Ceará," the organization wrote on Instagram.
"It has been [difficult] to find these animals in this state. The feeling of powerlessness over these huge tar patches on the coast is frightening and some public power position must be taken."