The Gorgol River joins the Senegal River a few kilometres from Kaédi, and the confluence area is one of the more biodiverse wetland zones in this part of southern Mauritania. The Gorgol valley supports hippos, various waterbirds, and an active riverine fishing culture. In the wet season (July to September) the river can flood substantially, making the lower valley largely inaccessible; in the dry season the water level drops and the river narrows to a navigable channel.
For birdwatchers, the area around the confluence is worth exploring — waders, kingfishers, herons, and the occasional African fish eagle are all present. A walk downriver from Kaédi toward the Gorgol mouth takes about an hour on foot and gives a sense of the vegetation change as you approach the more watered riparian zone.