This data set was used to calculate the energy budget and to calculate scope for growth for ecological engineers (intertidal mussels) comparing those that are affected by endolithic cyanobacterial parasites and clean intertidal mussels. It has data for growth, both whole body and shell biomineralization, and the reproductive potential of infested individuals. There is also data for components of scope for growth, feeding rates, ammonium exctretion, standard metabolic rates and lethal temperature measurements data.