The importance of rip-rap for round goby invasion success – a field habitat manipulation experiment

In a recent study, we showed how local-scale climate change impacts (increased temperature, reduced rainfall, shifts in peak rainfall) affected the hydrology of channelised lowland European river (reduced flow, reduction flood events, increased siltation, macrophyte growth), allowing native fish species to recolonise bankside zone and reduce density invasive round goby Neogobius melanostomus by effectively removing its preferred habitat, rip-rap bank stabilisation. Here, report on follow-on study whereby stretches newly vegetated were stripped back clean assess whether presence/absence was major factor affecting non-gobiid, tubenose Proterorhinus semilunaris abundance. Our results confirmed as increasing abundance, hence invasion success, rivers, while banks saw an increase abundance diversity non-gobiid species. While gobies no preference for habitat type, their numbers significantly colonised larger more aggressive gobies. We discuss our light artificial restoration measures undertaken Danube Rhine potential role flagship cost-effective, large scale projects with multiple ecosystem benefits.