The Golfo de Arauco is a large, productive bay located in the Biobío Region of central Chile. As the largest bay in central Chile, it is recognized for its exceptionally high levels of primary production, making it one of the most fertile marine environments in the southern portion of the country's coast. The gulf's ecosystem is significantly influenced by the freshwater discharge from the Biobío River and complex oceanographic processes, including seasonal upwelling, which drive nutrient cycling and biological productivity. This creates a rich environment supporting diverse marine life and significant fisheries.