The study of the ichthyofauna associated with soft bottoms allows a better understanding of the diverse activities necessary for the stability of the ecosystem, in addition to determining the variations in the population structure and being able to infer the possible effects of a before and after the construction of marinas and docks, which is important for coastal cities with adjacent lagoons such as the Laguna de La Paz located in the state of Baja California Sur, Mexico. On the other hand, establishing the interaction that anthropogenic impact has on fishes due to the dumping of sewage waste for years in the vicinity will allow adopting measures for their care.