Mean invertebrate density in the sublittoral zone was
similar between non-crayfish and crayfish sites (F = 0.71,
d.f. = 1, P = 0.41) (Fig. 2a), but, in contrast to stony and
vegetated habitats, density was higher in P€aij€anne
(F = 7.19, d.f. = 1, P = 0.02).