Microbiome and pollutants in the freshwater sponges Ephydatia muelleri (Lieberkühn, 1856) and Spongilla lacustris (Linnaeus, 1758) from the sub-Arctic Pasvik river (Northern Fennoscandia).

Despite the ecosystem functions offered by sponges in freshwater habitats, fragmentary studies have targeted their microbiome and the bioaccumulation of legacy and emerging organic micropollutants, making it difficult to test hypotheses about sponge-microbe specificity and response to environmental factors and stressors. The sponge species Ephydatia muelleri and Spongilla lacustris, coexisting in two sites of the Pasvik River (northern Fennoscandia), were analyzed for persistent organic pollutant (POPs) and chemicals of emerging concern (CECs), along with quali-quantitative microbiological features. River water and sediment were similarly treated to establish if the obtained data were site- or sponge-specific.