[Fish culture management of the Virelles pond [Belgium] and aquatic vegetation]

aquatic plants belgique belgium botanical composition bream breme brochet carp carpa carpe composition botanique ecosistema ecosystems farm management fish ponds gestion de l'exploitation agricole gestion des ressources lucio lucioperca manejo de fincas perca perch perche pike pike perch plante aquatique population dynamics potamogeton resource management sandre sargo tanche tenca tench