Table 1 Geographical locations of the Nidda sampling sites
Site | Coordinates | Fish zone | Description |
|---|---|---|---|
N1 | 50°27′11″N 9°02′20″E | Lower trout zone (metarhithral) | Reference site, downstream the Nidda river dam |
N2 | 50°25′51″N 9°01′20″E | Grayling zone (hyporithral) | Downstream of industrial dischargers |
N3 | 50°23′09″N 8°58′25″E | Barbel zone (epipotamal) | Downstream a class-IV WWTP (35,000 pe) |
N6 | 50°16′42″N 8°47′09″E | Barbel zone (epipotamal) | Downstream a class-IV WWTP (30,000 pe), two class-III WWTPs (7000 pe), four renaturalised river sections and the afflux of the Horloff as well as the Usa/Wetter tributary |