Macrozoobenthic invasion is a common phenomenon which appears throughout the world.Humans travel worldwide transporting materials from one continent to another.This enables many aquatic species to breach natural boundaries and invade environments in other regions and continents.With modern travel the number of species moving between different regions has increased considerably and so the number of successful aquatic invasions has increased.To be a successful invading species,there are some necessary traits.Mobility,small body size,adaptability and a high reproductive rate for example,would contribute to a successful cross-regional invasion.But the new host environment must fit some accommodating criteria.Environments that are depleted of their historical species due to human impact damage,may make little or no resistance to new organism invasions.German water bodies are under serious stress from human impact.Many water bodies are irreparably disturbed and some are now totally artificial habitats.These water bodies are a complex network of connecting rivers and canals that facilitate the spread of invasive macrozoobenthic species.Our literature research and our own investigations show that water bodies,rivers and streams that are under stress from human impact,or damaged by direct interference,are more vulnerable to aquatic invasive species alien to the local natural environment,than water bodies more closely aligned to their original,natural conditions.