TREAM: Time series of freshwater macroinvertebrate abundances and site characteristics of European streams and rivers

Freshwater macroinvertebrates are a diverse group that play many key ecological roles, including accelerating nutrient cycling, filtering water, controlling aquatic primary producers, and providing food for predators. Since they rapidly respond to environmental changes, macroinvertebrate community composition is a commonly used indicator of water quality. In Europe, efforts to improve water quality following environmental legislation, primarily starting in the 1980s, may have driven a recovery of macroinvertebrate communities. Towards understanding temporal changes of these organisms, we compiled the TREAM database (Time seRies of European freshwAter Macroinvertebrates). The TREAM database consists of whole macroinvertebrate community time series from 1,816 river and stream sites (mean length of 19.2 years with 14.9 sampling years) of 22 European countries sampled between 1968 and 2020. In total, the data include >93 million sampled individuals of 2,648 taxa from 959 genera and 212 families. These data can be used to ask a wide range of questions from identifying drivers of the population dynamics of specific taxa to assessing the success of legislative and management restoration efforts.