Invasive species are among the most serious threats for biodiversity and ecosystem services nowadays, especially in freshwater ecosystems. The spread of invasive species is difficult to prevent and eradication programs have been of limited success in completely removing invasive species, whereas costs of such programs are massive. As the consequences of invasions may not be equally detrimental for different invasive species and across ecosystems, a cost-effective way of spending money and resources in eradication requires knowledge on the consequences of species invasions. Here we propose the invasion of submerged macrophytes in shallow water bodies as a model system to measure the services provided by invasive relative to native submerged macrophytes with respect to improvement in water quality and enhancement of biodiversity. We propose to compare the performance of a guild of seven fine-leaved macrophyte species, of which 3 invasive. We propose to test the roles of invasive and native submerged macrophytes in suppressing algal blooms, providing food for herbivores, providing structural habitat for macrofauna and affecting plant diversity and the occurrence of target species for conservation. This project will generate fundamental knowledge on the importance of species identity for ecosystem functions of submerged macrophytes as well as knowledge that can make the eradication of macrophytes more cost effective for water- and nature managers.