Nowadays, improved fishing technology and depleted stocks cause fishery shocks in sensitive regions that lead to job losses and added insecurity. In fishery-dependent communities, more and more fishers are moving countries looking for a living. This study aims to know the perception of migrants in Spain about the sustainability of fishing in their countries of origin and how this perception influenced their individual behaviors and their decision to move. To this end, 203 families from 32 countries differentially affected by fishery shocks in Africa and Latin America were interviewed face-to-face to quantify the perceived weight of fishery changes on their decision to move, compared with socioeconomic and security reasons. The perception of fishing declines and their importance as a cause of mobility were positively and significantly correlated. Our study highlights the important and unexplored link between human mobility and fishery depletion, supporting the idea that fishing declines—induced at least partially by climate change—are one of the causes of mobility.