Espessa layer of algae and green organic matter covers the Ribeirão São Jerônimo, a tributary of the Rio Tietê in Zacarias (SP), for several days. The dense material, with the appearance of silt in shades of green and blue, covers much of the surface of the stream and, in some places, completely blocks the water. Objetos that fall on the mass do not sink, and the unbearable odor has driven away residents and fishermen from the region since the problem has intensified in recent months.
Situação getting worse since January
Public employee Mauro Gava and his family abandoned the ranch on the property due to the smell and appearance of the water. Segundo residents, the green crust began to appear in January and progressively worsened. The self-employed Valdecir Giusti, who has a ranch on the banks of the river, reports that the phenomenon began with small green dots that gradually increased over the years.
“We would go out fishing by boat. As the years went by, the green spots in the water would increase. Quando when the dry season arrived, it would increase. Até reached this point”, describes Valdecir to TV TEM. The green crust accumulates on the banks of the stream and has an appearance similar to algae. Para tries to alleviate the situation, the resident removes part of the material manually.
Impacto directly into fishing and tourism
Fisherman Silécio José Francisco notes a significant reduction in the number of fish caught in the last 3 years. Green water harms fishing and makes recreational use impossible. “Three years ago, it was crazy what fish we caught. Agora isn’t enough. With this green water, it’s really bad to catch fish. It’s sad to see the water like this. It’s water that we’ve even made food with”, reports Silécio to TV TEM.
The main documented effects include:
- Água unsuitable for bathing and consumption
- Diminuição sharp fish in the region
- Unbearable Odor that drives away residents and tourists
- Water Leisure Impossibilidade
- Deterioração of the quality of life of riverside communities
Características physics and material composition
The layer of organic matter is dense enough to support the weight of objects thrown over it. The material occupies a large area of the riverbed and, as observed by TV TEM during field verification, the green mass extends across several stretches of the Tietê tributary. The color mixes green and blue, and the appearance resembles viscous slime. The bad smell associated with the green crust prevents residents and tourists from accessing the banks of the river, transforming an area that was previously used for fishing and recreation into an unsuitable area for staying.
