Mixed diet feeding experiment data from: Invasive bryozoan alters interaction between a native grazer and its algal food. A Canadian Healthy Oceans Network Ecosystem Function Project, EF-11.

Rate of mass change (mg/day) of kelp tissue half disks (Saccharina latissima) in feeding arenas in the laboratory with snails (Lacuna vincta) offered dietary choice of kelp encrusted by invasive bryozoan M. membranacea or non-encrusted kelp simultaneously and in autogenic control arenas with no snails. Data include arena identity, herbivore absence/presence, dietary item (encrusted/non-encrusted), rate of mass change of kelp tissue.