Negro River Environmental Assessment

Abstract

The Negro River comprises a multi compartmentalized environment which links Los Andes mountains with the Atlantic Ocean. Due to its relevance in terms of industries, intensive agriculture production and population is considered the second Argentinean river in importance; however, these economic activities have increased the environmental pressure, raising concerns. For instance, the intensive agriculture joint with urban settlements and industries have lead to the introduction of several Persistent Organic Pollutants, including legacy compounds (such as DDT and HCHs), new generation pesticides (endosulfan) and urban-industrial POPs (PCBs, PBDEs). In addition, several matrix have been shown to receive and accumulate heavy metal loads, including As, Cd, Cr, Co, Cu, Fe, Hg, Mn, Ni, Pb and Zn. Metal bioaccumulation and transference between environmental compartments (water, sediments, fish and mollusks) have been demonstrated to occur through the years. The anthropic activities have also induced changes in the aquatic macroinvertebrate assemblages of the Negro River, where both, water quality and invasive species, appear to be main drivers of the change. Added to this, from 17 fish species, only 9 are native, leading to a low zoogeographic integrity coefficient. Finally, the environmental quality threats, climate change and hydroelectric facilities pose synergistic new risks which are addressed in this chapter and further discussed.