A SIBEO (Spanish acronym for sistema de bombeo por energía de oleaje) wave-driven seawater pump is proposed for managing the volume and salinity of a coastal lagoon on the Mexican Pacific coast. The observed variation in volume and salinity of the Lagartero lagoon during most of the year when the sandbar is closed is adequately reproduced by a model that assumes an evaporation–precipitation controlled closed basin. The model was employed to examine the use of a SIBEO for controlling the lagoon volume and salinity. Continuous seawater pumping maintains a water level that favors the greatest number of sandbar openings at the end of the rainy season and thus the intake of shrimp larvae, while not significantly affecting the observed yearly salinity cycle. The possible effects of the SIBEO seawater pumping on lagoon eutrophication and shrimp production are discussed in this article. It seems likely that SIBEO seawater pumping will help curb eutrophication and significantly increase shrimp production in the lagoon.