This study shows: Over 40 percent of extant large freshwater animals (megafauna) have been deliberately introduced outside their natural ranges, often for economic gain. While these alien species can provide substantial benefits to certain groups in the introduced regions, they also posed profound and often underestimated risks to native biodiversity and local people. 

The authors enhanced a tracer-aided hydrological model to help constrain estimates of ecohydrological partitioning and water balance compartments in sub-catchments of the Middle Spree catchment. They disentangled ecohydrological funtioning in this ET dominated region despite the complexity of the heterogeneous landuse, extensive hydraulic infrastructure and long legacy of intensive management.

Since the 1980s mean discharge has declined by around 50% and - without aquatic vegetation – also the water level. Dense stands of aquatic plants have kept the water level high in recent summers despite lowered discharge. Most water was retained in adjacent floodplain aquifers rather than in the river channel.