From lakes to rivers: Downstream larval distribution of Dreissena polymorpha in Irish river basins

Three different river sizes were examined at various distances downstream of Irish lakes containing zebra mussel populations. The larger rivers contained zebra mussel larvae and adults at a wide range of densities throughout their length. However, smaller rivers demonstrated a rapid decline of larvae and adults with progression downstream. River sections downstream of interconnected lakes were also examined as part of this study. The fate of the zebra mussel larvae in medium and small rivers remains unknown.