This is an image of the Rio Gurupi and its delta in the Brazilian state of Maranhao. It is the only open-sea delta in the Americas and has more than 70 islands of various sizes. These islands are covered with mangrove forests, dunes, waterways, freshwater lagoons, and natural beaches. This area is part of the Gurupi Biological Reserve, a Brazilian National Biological Reserve. The Gurupi River Delta region is home to hundreds of bird and fish species. In this image the Gurupi River is releasing lots of sediment into the Atlantic Ocean. This could be the result of deforestation upstream, exchanging forested land for agricultural use, or from gold mining in the Gurupi region.