the region of the amazon in brazil has an extension of containing diverse fundamental ecosystems. one of these ecosystems is a floodplain, or a várzea forest, and is home to a large number of fish species which are an essential resource for human consumption. the várzea is also a major source of income through excessive local commercialized fishing. várzea consist of muddy river waters containing a vast number and diversity of nutrient-rich species. the abundance of distinct fish species lures the amazon river dolphin into the várzea areas of high water occurrences during the seasonal flooding.