Colonisation of the Rhine basin by non-native gobiids: an update of the situation in France

Three of the four species of non-native gobiids currently reported in the Rhine basin were recently recorded in France: the Western tubenose goby in 2007, the bighead goby in 2010 and the round goby in 2011. The bighead goby and the round goby displayed a very high rate of range expansion, suggesting a human-assisted colonisation through inland navigation. An assessment of the invasiveness potential by the FISK (Fish Invasiveness Screening Kit) reveals a medium risk for the Western tubenose goby, while the bighead goby and the round goby are at high risk of becoming invasive in France. This assessment is consistent with our observations since there has been a steady increase in the range of the Western tubenose goby, although in low numbers, while the relative abundance of bighead goby and round goby, recently arrived in the French part of the Rhine River and Moselle River, can be high. Given their fast expansion, it can be assumed that these species will soon reach other French basins, particularly in the south (Rhone basin) and in the west (Seine basin), and the implementation of measures to limit their spread should be considered.