Phytobenthos are good indicators of nutrient enrichment and other pressures, and can be used to assess river water quality. Diatoms are the main plant groups that we use because their silica shells are easy to identify under the microscope. The method is based on the principle that different diatoms have different environmental preferences, so we record the species found, along with their relative abundance.
The method statement published in 2014 for the second river basin planning cycle has now been updated for the third cycle. The latest version of the DARLEQ tool is DARLEQ3 v.0.9.8. This is available in the zip file below, or as a Shiny app version at DARLEQ3 Shiny