The Pateira is a natural lake , the largest in the Iberian Peninsula , located in the triangle Agueda , Aveiro - Requeixo Parish of Oliveira do Bairro , before the confluence of the river with Cértima the river Agueda .This pond has high ecological wealth and incorporates Special Protection Area of the Ria de Aveiro , included in the Natura 2000 Network .It's great faunal biodiversity Pateira . Species as can be observed: Purple Heron , the Black Kite , the marsh harrier , the eagle -winged - round , the Kingfisher, the Stilt , the duck - mad , the Coot , among other species of herons , fox passerines , etc. . The term " Pateira " results from the abundance of ducks . Thus , the diversity of habitats allows the support of these communities , and other groups such as fish ( Boga , Bardo do Norte , Boga - Portuguese , Ruivaco , Bordallo , Eel , Pardelha , Largemouth Bass , Pike , Carp , Mullet , Soon , Pimpões ) , the Reptiles , amphibians , molluscs (mussels - the - river ) , crustaceans ( lobster - red) .Regarding the floristic biodiversity, wetland , which includes free water and flooded the banks and vegetation lines dominate habitats with stands of Reed, along with Tabúa and bulrush . Communities still occur : the Yerba pinheirinha the lilies or even Hyacinth water. In some marginal areas along the Pateira , there are several tree and shrub species such as willows , poplars , alders , Buckthorn , ash , hawthorn , Sabugue , Borrazeiras punctually oaks , laurels , Elms , etc. . Group of herbaceous and sub - shrub refers only to the presence of yellow- lily - of - marshes , the cress , the Embude , Yerba peach tree and mint - in - water.