During floods these streams communicate with one another and mix with the Paraguay river water, renewing and fertilizing the region. Nevertheless, just like in other Brazilian ecosystems, where predatory settlements are causing destruction, interference with the Pantanal ecosystem is already being felt. Although much of the region is still unexplored, there are numerous threats arising from economic interest in the area. The situation has worsened in the last 20 years, particularly because of the introduction of exotic forage plants and the exploitation of wooded areas. The Pantanal ecosystem basically depends on inflow and outflow during the flood cycles which, in turn, are directly linked to rainfall in the entire watershed.
Rain usually occurs in the headwaters of the rivers which run into the lowland.
The same occurs with the Paraguay affluent streams. The water spreads and covers broad expanses, seeking a natural outlet, which will only be found hundreds of kilometers downstream, at the confluence of the river and the Atlantic Ocean, beyond the Brazilian territory. Every May the ebbing starts and the water level slowly begins to fall. The wealth of the pantanal Nature repeats, every year, the spectacle of the floods that ensure the renewal of the fauna and flora of the Pantanal . The huge volume of water, which practically covers the whole Pantanal region, is a veritable fresh water ocean, where thousands of fish live.