Located in the East of the complex of wetlands in southern Benin, the Lower Valley of Ouémé
includes water bodies (Lake Nokoué, Lagoon of Porto-Novo, Sô and Ouémé rivers), relics of
forest, mangroves, flooded savannas, grasslands, plantations, fields and fallows. Annual counts
of waterbirds were conducted over a period of ten years. Eighty-seven species of waterbirds
belonging to 48 genera, 19 families and 9 orders were recorded during the period 1998 to 2004
and 2008 to 2010. Correspondence analysis and discriminant analysis applied to matrices
species / sites x years allowed determining two groups of waterbirds A and B established along
a salt gradient.