Figure 3.

Difference in wet-weight change (g) between artificial food containing seaweed material from knotted wrack that received water with and without water-borne cues in the induction experiment. Periwinkles were deterred by artificial food containing seaweed material from knotted wrack receiving water-borne cues, as indicated by the significantly (one-way analysis of variance, F_1,38 = 35.59, P < 0.0001) lower difference in wet-weight change between the two artificial food types offered to periwinkles compared with wet-weight change between controls without herbivores. Error bars show SEM (n = 20).