Dataset of biological quality elements recorded in rivers and streams across Luxembourg at selected monitoring sites. Data are collected within the framework of the national monitoring programme under the Water Framework Directive (2000/60/EC) and complementary ecological assessment activities. Data collection is supervised by the Administration de la gestion de l’eau (AGE).

The dataset includes raw biological monitoring data from fish (LU-SW-BIO-FISH), macrophytes (LU-SW-BIO-MP), macroinvertebrates (LU-SW-BIO-MZB), and phytobenthos (LU-SW-BIO-PB).

Fish surveys follow the standardized protocols XP T90‑383 (AFNOR, 2008) for single-pass electrofishing sampling and NF T90-344 (AFNOR, 2011) for the detemination of the Fish Based Index. Fish species abundance is reported as the absolute number of individuals per species recorded during a single electrofishing pass. Crayfish species captured during electrofishing surveys are also included in the dataset.

Macrophyte surveys follow the standardized protocols NF EN 14184 (AFNOR, 2014) for the surveying of aquatic macrophytes in running waters, and NF T90-395 (AFNOR, 2003) for the determination of the Macrophyte Biological Index for Rivers (IBMR). Coverage represents the relative area (%) covered by each species within the surveyed river section.

Macroinvertebrate surveys conducted in 2015 and 2016 followed the standardized protocols XP T90-333 (AFNOR 2009) for sampling of aquatic macroinvertebrates in shallow freshwaters and XP T90-388 (AFNOR 2010) for laboratory processing and taxonomic identification of macroinvertebrate samples. Surveys conducted between 2017 and 2020 followed the standardized protocols NF T90-333 (AFNOR, 2016) and XP T90-388 (AFNOR, 2010). Surveys conducted between 2021 and 2025 followed the standardized protocols NF T90-333 (AFNOR, 2016) and NF T90-388 (AFNOR, 2020). Abundance is reported as the absolute number/count of individuals per taxon.

Phytobenthos surveys follow the European standardized protocols BS EN 13946 (2003) for the routine sampling and pretreatment of benthic diatoms from rivers and BS EN 14407 (2014) for the identification and enumeration of benthic diatom samples from rivers and lakes. Species abundance is determined from a fixed count of 400 individuals per sample and reported as absolute abundance (number of individuals per taxon).