Biodiversity and Habitat Diversity Biodiversity of small waterbodies

The 2024 status report based on data from 2018-2021 shows that the loss of habitat diversity has a negative impact on macrozoobenthos diversity in small water bodies. A status update will be provided in 2028.

Due to limited data base, the impact indicator “biodiversity and habitat diversity” could so far only be applied to the small water body type “Sölle of the North German Plain” without a temporal comparison or distinction between agricultural areas. With regard to the influence of habitat diversity on macrozoobenthos diversity, 70% of the small water bodies examined were not in good condition. This result highlights the urgency of promoting and maintaining habitat diversity in water bodies in agricultural landscapes, for example through edge strips.

The data basis is the water-specific taxonomic macrozoobenthos composition with the number of individuals per taxon and the number of habitat types (sediment, emersed macrophytes, sub-merged macrophytes, submerged roots, fallen leaves or dead wood), which occur along the shoreline in a proportion of more than 5%. The indicator values calculated using representative samples within the small water body backdrop (>0.15 ha to <1.0 ha) are reported at national level. Where the spatial coverage of the samples allows, the national reporting level can be supplemented with agricultural area-specific statements. With the start of implementation of the monitoring, the first results will be available from 2023; the indicator will be reported completely after renewed data collection at 5-year intervals. The reported condition classes are adapted to soils in the North German lowlands from regions of high-intensity and intensive agriculture and are not yet suitable for classifying small water bodies with different characterizations or agricultural pressures.