Families can spend a night sitting on Southern California's sandy shore waiting for the legendary grunion run to begin. Doors open at 8pm. The activities start with an auditorium presentation (9pm) about the mating rituals of this unique fish, after which visitors are guided down to the shore to see the famed fish run for themselves (see schedule for predicted run times).

Warm clothing and a flashlight are recommended. Once a year, the Aquarium holds its signature Grunion Fish-tival, with a few extra additions to the night's events.

Grunion are sardine-size fish of the silversides family, which are among the few species of fish that actually come ashore to lay their eggs on sandy beaches. They are found from Southern California south to Baja California and arrive at night after the high tide around the new moon and full moon. Cabrillo Beach is one of the better places to observe the fish.

April and May are closed season (observation only). March, June, and July are open season, when grunion may be caught (by hand only); a valid California fishing license is required for anyone 16 years or older.

Note that there is an April 6  grunion program that is free but members only; memberships to the aquarium start at $25.