WFD – Loire-Bretagne Basin – Ecological status – Biological status – Fish

The analysis focuses on monitoring fish populations only in the transitional water bodies of the Western Channel and the Bay of Biscay and assessing their biological quality.
The ELFI fish indicator in French estuaries associated with this quality element is based on:
- total density of fish,
- density of diadromous fish,
- density of marine juveniles (in meso. and polyhaline areas),
- density of freshwater fish (in oligohaline areas),
- density of resident species,
- density of benthic fish,
- taxonomic wealth.

The water bodies monitored are sampled twice a year, three consecutive years for the calculation of the indicator. The most recent assessment is presented in the DCE Loire-Bretagne Atlas. Previous statements are available in annual archives