The global whale-watching (WW) industry has grown exponentially, becoming one of the most productive tourism sectors in many regions of the world, namely in the Azores. Managing WW sustainably is vital not only for cetacean welfare, but should be a natural interest of the industry and authorities. Yet, establishing direct relationship between cetacean exposure to WW and biological significant effects at the population level is challenging. To assess WW disturbance and adequately manage the activity, we need to understand cumulative effects of WW interactions on the vital rates (survival and reproductive success) of individual animals and how this, in turn, may impact the dynamics of populations.