How the waters of the river can influence the fish that reach the Amazonians' tables The type of river can help explain the diversity of fish found on the Amazonians' tables. This is the relationship presented by Rio gastronome Thiago Loeser, creator of the Odisseia Gourmet project, which analyzed how the characteristics of the Amazon waters are linked to the environments, biodiversity and eating habits of different regions of the state. In a video that gained repercussion on social media, Loeser argues that the Amazon does not have a single cuisine, but different forms of food built on the relationship between populations and rivers. "In Amazonas, it's not just the river that rules the kitchen, but the type of river. There are three types of water there and each one sets a completely different table", summarizes Loeser. ? Join the g1 AM channel on WhatsApp According to the gastronome, factors such as water composition, temperature and origin of rivers help to understand why certain species are more present in some areas of the Amazon. The relationship, however, is more complex for science. Researcher and doctor in aquatic ecology Edinbergh Caldas de Oliveira explains that, although rivers have their own characteristics, many species of fish circulate through different environments and are not restricted to a single type of water. How different types of water form different environments The analysis presented by Thiago Loeser considers concepts from limnology, a science that studies continental waters. The characteristics of rivers influence the environments where plants and animals live and help explain the relationship between nature, fishing and food. Muddy waters, like those of the Solimões River, originate in the Andes Mountains and reach the Amazon loaded with sediments and minerals. With a color similar to a "coffee with milk", they fertilize floodplain areas during flood and drought cycles. This environment favors riverside agriculture and is also home to large and commercially important species, such as tambaqui. The black waters, like those of the Rio Negro, have a dark color, similar to that of strong tea. These are more acidic waters with a small amount of mineral sediments. Despite its appearance, the Rio Negro is home to one of the greatest fish biodiversity on the planet. The presence of smaller species with reduced populations helped transform Barcelos into a global reference in aquarium farming and sustainable fishing for cardinal fish. Clear water rivers are also part of the Amazonian diversity and have their own characteristics, which influence the environments found in each region. CURIOUS: Giant Tambaqui draws attention at a fair in Amazonas; expert says fish is rare DISCOVER: Discover ten fish found in the Amazon that pose risks to humans UNDERSTAND: Is Tambaqui threatened with extinction? Understand the classification of typical Amazonian fish The meeting of the waters shows differences between the rivers Meeting of the waters in the Amazon Disclosure One of the best-known examples of the diversity of Amazonian rivers is in Manaus, where the waters of the Negro and Solimões rivers meet. The Rio Negro has warmer, acidic and slower-moving water. Solimões has colder, denser and faster water. The differences between them cause the rivers to run side by side for kilometers before completely mixing. The phenomenon occurs due to the difference in water density and has become one of the most famous natural landscapes in the Amazon. Between gastronomy, science and traditional knowledge To g1, Thiago Loeser said that the project was born from the desire to show gastronomy as a way of understanding the culture and environment of each region. "When I decide on themes for a region, I try to go beyond the typical recipe. As a gastronome, I analyze the environment, as the ecosystem affects biodiversity and customs. The composition of the river defines which inputs will be accessible to the native", he explains. The material is produced independently, with academic research, images and reports from local residents. "Much of our food culture does not have academic documentation. It survives in the oral form of riverside dwellers, quilombolas and indigenous people. I cannot have an elitist mindset that only what is in articles is valid. It is necessary to respect science, but also understand the wealth of popular knowledge." What science says about the relationship between rivers and fish Edinbergh Caldas de Oliveira agrees that Amazonian rivers have different characteristics, but highlights that the distribution of species depends on several factors and not just the type of water. According to him, the biodiversity of the Rio Negro is linked to complex food chains, but this environment is also more fragile. "It is an ecosystem with enormous richness of species due to very complex food chains, but which are fragile due to low primary production. There are many species involved, but they occur in small population numbers compared to white water rivers", explains the professor. In periods of climate crisis and severe droughts, this characteristic makes rivers with black and clear water more vulnerable than the Solimões/Amazonas, which has a greater volume of water and faster recovery. Fish move through different environments in the Amazon. The researcher's main reservation is the idea that each type of water alone determines which species reach the table. According to Edinbergh, many Amazonian fish are migratory and travel great distances throughout their lives. "From an ecological point of view, it is difficult to make this rigid separation by rivers. Species of great commercial and food value, such as tambaqui, jaraqui and large catfish (piraíba, surubim), are migratory. They have home ranges that cover hundreds of kilometers, moving between river channels, lakes and flooded forests (igapós and floodplains) to spawn, grow and feed", he explains. The researcher explains that