Summary 1. Ship‐induced waves disturb benthic invertebrate assemblages colonizing littoral zones of lakes and rivers. However, the impact of ship‐induced waves on invertebrates has rarely been quantified, and the influencing factors have not been addressed. 2. In an experimental wave tank, five benthic invertebrate species, Bithynia tentaculata, Calopteryx splendens, Dikerogammarus villosus, Gammarus roeseli and Laccophilus hyalinus, were exposed to waves of increasing shear stress (0.43–2.19 N m−2). Mean number of detached individuals was recorded for five littoral habitats [coarse woody debris (CWD), reeds, sand, stones and tree roots], representing different levels of structural complexity as quantified by their fractal dimensions (FD). 3. Results showed that detachment of invertebrates was significantly related to shear stress in all habitats except tree roots. Detachments averaged for the five species were significantly lower in habitats with a high degree of structural complexity, decreasing in the habitat sequence: sand, CWD, stones, reeds and tree roots. 4. Consistent with their different morphologies and methods of attachment to substrates, the five species displayed differences in their response to hydraulic stress that were dependent on habitat. 5. The increasing sheltering effect of structural habitat complexity was mirrored by increasing dissipation of the kinetic energy of waves; i.e. the FD of the habitat was positively correlated with shear stress reduction due to the flow resistance of the habitat. 6. Network habitats such as tree roots provided the best sheltering conditions against hydraulic disturbance, because they combined good refuge availability for all studied invertebrate species and maximal dissipation of kinetic wave energy. Consequently, persistent anthropogenic impacts, such as lakeshore modification or long‐term exposure to ship‐induced waves, which cause disappearance of complex littoral habitats such as tree roots or dense reed belts, will drastically increase the adverse effects of boating and ship traffic on littoral invertebrate assemblages.

Re-meandering of degraded rivers is a frequently implemented measure in river restoration. A simple solution is reconnection of old meanders; however, its success likely depends on the reconnection method. We conducted a field study to analyze the benefits of a fully reconnected (fully opened meander, blocked main channel) and a partially reconnected meander (opened downstream, pipe bypass from main channel upstream, still open main channel) for macroinvertebrate communities in a German lowland river. Immediately upon reconnection of the two meanders, habitat diversity, and macroinvertebrates were recorded for three years with sampling in spring and in summer each year. The results of a principal response curve analysis show that the macroinvertebrate community in the fully reconnected meander reflected main channel reference conditions after 1.5 years. The macroinvertebrate community composition was not improved relative to in-stream reference conditions within the partially reconnected meander, which could be attributed to the almost complete lack of flow changes that resulted in missing improvements of substrate diversity. Our results show that the meander reconnection method must sufficiently affect the basic hydromorphological requirements to achieve reference macroinvertebrate community composition. Measures including hydromorphological conditions are therefore recommended for employment in environmental management.