Danish Stream Fauna Index (DSFI)

The DSFI is used primarily to measure organic pollution in Danish streams. It is an indicator of stream health.

The Danish Stream Fauna Index (DSFI) was developed as Denmark’s national standard biomonitoring method. The DSFI is a biological index that is intended to measure the degree of instream pollution. This methodology uses macroinvertebrate taxa based on their sensitivity towards variable oxygen levels, thus the DSFI is most sensitive toward organic pollution. Index values range from 1 (impacted condition) to 7 (non impacted condition).

Sampling for the DSFI is carried out at over monitoring stations as part of Denmark’s national water quality program. Sampling is achieved using hand nets along transects across each stream at about 10m apart. Transects are undertaken, with samples taken along each transect across the stream. Sampling is carried out using kick-sampling and hand-sampling of the stream substrate; this constitutes the total fauna sample. Near-bank sampling of each substrate is necessary in deep rivers where the channel bottom cannot be reached. A laboratory is used for sorting, identification and counting of samples. Macroinvertebrates are identified to at least the taxonomic level.

The DSFI calculation methodology is as follows:
1. There are six sub-indicators, called indicator groups (IG), which contribute to the DSFI. Each IG contains a list of specific taxa.
2. A taxon within an indicator group is said to be present within a sample if ≥2 specimens are kick-sampled, or if ≥1 specimen is hand-sampled.
3. Two diversity groups are defined, containing 10 specific taxa each. These are called positive and negative diversity groups.
4. The total present taxa from the negative diversity group are subtracted from the total present taxa from the positive diversity group to produce a DSFI score ranging from -2 to 7, depending on which IG is assessed.
5. Higher DSFI scores are considered indicative of good water quality, whereas lower scores are indicative of polluted water.

Taxa are categorised by their resistance or sensitivity to pollution. The lower the IG group (from 1-6), the more sensitive taxa are present. Thus for badly polluted streams, one is likely to find the presence of species from IG 6, therefore that DSFI index score will be calculated from IG 6, which will naturally result in a low score (IG 6 has a maximum score of 1, whereas IG 1 has a maximum score of 7).

The assessment criteria for the DSFI are entirely based on macroinvertebrate sampling

The DSFI is a macroinvertebrate index that uses lab measures for taxonomic categorisation.

Macroinvertebrate sampling. Database management and assessment.

The DSFI requires a field sampling team with nets and other sampling equipment. A laboratory is required for categorisation of macroinvertebrate samples.

The DSFI produces an index score. Index scores are based on six indicator groups which each give a different indication of water quality.

• National water quality monitoring in Denmark
• Decision support
• Prioritisation for waterway management.

The DSFI is used by the national environmental agency of Denmark. Its outputs are useful for government agencies, NGOs and land managers.

Use of positive and negative categories of macroinvertebrates.

Methodology may be dated (1998). Specialised expertise on invertebrate identification and data management required.

Waterview db: Review of European assessment methods for rivers and streams

This page should be cited as:

Department of Environment, Science and Innovation, Queensland (2019) Danish Stream Fauna Index (DSFI), WetlandInfo website, accessed 18 March 2024. Available at: https://wetlandinfo.des.qld.gov.au/wetlands/resources/tools/assessment-search-tool/danish-stream-fauna-index-dsfi/