Río de la Plata Estuary

The Río de la Plata (RdlP), a funnel-shaped estuarine system, located on the east coast of South America, is a complex inner shelf area, draining the second-largest basin of the continent to the Atlantic Ocean. It is unique in terms of social and economic array; its basin comprises five countries accounting for more than 75% of their Gross National Product. Roughly 150 million people inhabit the RdlP basin. An agreement signed in 1973 between Uruguay and Argentina, established the maritime limits, the shared use and management of bilateral waters and resources, as well as, a common fishing zone in the Atlantic Ocean, regulated by binational administrative commissions. The petrochemical pole located in the western coastal plain of the RdlP estuary, has modified the hydrodynamics of the area through piping and landfilling actions. These changes, along with the leaking of effluent derived from industrial activity, resulted in modifications to the surface and groundwater chemistry in this coastal plain sector. The system is experiencing a continuous but moderate sea level rise and suffering an extraordinary rise in the flow of the main tributaries from the early 70s to the early 2000s. Also, the frequency of extreme events, mainly wind-induced storm surges, has risen over the last three decades. Eutrophication processes in the RdlP resulting from nutrient inputs linked to human activities in the del Plata basin are regulated by hydrological, oceanographic, meteorological factors and climatic events. At present, anthropogenic eutrophication is one of the most important environmental impacts on RdlP ecosystem's health and services. Massive cyanobacteria blooms promoted by nutrient enrichment associated with hydrological, oceanographic and meteorological factors have been reported more frequently in the last years, generating a loss of water quality, cultural ecosystem services and tourism revenues. The proposed solutions to the main threats faced by the RdlP basin, include/are related to (1) strengthen coordination between countries; (2) improve agricultural cultivation methods to conserve soil and water; (3) adopt non-engineering measures to reduce flood risks, such as flood forecasting and insurance services in flood-prone areas; (4) draft strict development and protection plans for the Pantanal Wetland and implement them effectively; (5) strengthen the management of water pollution prevention and control; 6) protect the ecological environment of the watershed; (7) develop corresponding laws, regulations and international conventions; (8) establish institutions for legislative supervision and law enforcement.