Further global warming is projected to increase coastal erosion. Therefore, coastal protection is being intensified with a strong emphasis placed on environmental biotechniques. One such activity is anti-erosion planting using alien plant species. The aliens penetrate from the plant species into the natural ecosystems, reducing their biodiversity and ecosystem services. Parallel to coastal protection, measures for nature conservation are undertaken to eliminate invasive aliens from the natural ecosystems that take over. Such actions are featured in the master plans drafted for the Natura 2000 sites on the south Baltic coast. Although there is no sufficient scientific evidence,