The Aquarium will open at 8 p.m. and a film on grunion begins at 9 p.m. in the John M. Olguin Auditorium. Prior to the predicted run, everyone will gather on the beach to await the grunion. The program cost is $5 for adults and $1 for seniors, students, and children. Warm clothing is recommended.

Grunion run at Cabrillo Marine Aquarium in San Pedro, California from SanPedroNewsPilot on Vimeo.
Grunion are small sardine-size fish of the silversides family, which are one of the few species of fish that actually come ashore to lay their eggs on sandy beaches. They are found from central California through Baja California, with Cabrillo Beach being one of the better places to observe the fish.

At times the beach may look as if it is covered in a blanket of silver as the wriggling fish arrive to mate. The females burrow into the sand to lay eggs while the males wrap around them in to fertilize the eggs. Then both males and females catch the next wave back out to sea. The fertilized eggs incubate for about 9 days in the sand before the tumbling action of the waves from the next series of highest tides cause them to hatch, and carries them back out to sea.