Table 2: The number of sites occupied by the native species and the alien brook trout (Salvelinus fontinalis). Total number of sites was 78 in both years.

SpeciesNumber of sites (1994)Number of sites (2004)Difference

Salmo trutta 1+56648
Salmo trutta 0+3223−9
Salvelinus fontinalis 1+21287
Salvelinus fontinalis 0+152712
Lampetra planeri3222−10
Phoxinus phoxinus375417
Lota lota327−25
Cottus gobio69701
Thymallus thymallus8124
Pungitius pungitius16204