The upper river flows over a rocky substrate with many rapids and waterfalls, making it unsuitable for navigation, though it does make it suitable for electricity production. The lower river is a shallow, funnel-shaped, mesotidal,
mangrove-fringed, tide-dominated
estuary. Rice farms have been established in the mangrove areas of the delta "with some success".
Wildlife The river is home to 96 recorded freshwater fish species. The estuary, along with part of Sangareya Bay and the mouths of the Konkouré and Bouramaya rivers, has been designated an
Important Bird Area (IBA) by
BirdLife International because it supports significant populations of
western reef egrets,
pied avocets and
common redshanks. It encompasses 28,000 ha of mangroves,
mudflats, sandbanks and rice-fields.
African manatees occur in the mangroves and
common bottlenose dolphins in the bay. ==Dams==