Just after nightfall in southern California, on sandy stretches of Pacific shoreline, a piece of marine folklore is coming to life.
It’s that time of year again. The grunion are running.
Grunion are skinny, silvery little fish only 5 to 6 inches (13 to 15 centimeters) long. They’re not harvested commercially, and they’d probably go unnoticed if it weren’t for the unusual way they spawn.
But the way they flop, en masse, out of the water and onto the shoreline, dig into the sand to lay eggs, and then scoot back into the surf has become the stuff of legend in southern California.
Natives get a kick out of taking out-of-town guests to see the nighttime spectacle, which occurs each year between March and August on beaches from Point Conception, just north of Santa Barbara, down to Punta Abreojos in Baja California, Mexico. California grunion, members of the Atherinopsidae family, or New World silversides, are found nowhere else in the world.
But how much longer will they be found here? Anecdotal evidence suggests that as hunting has increased, and as development has reduced available spawning grounds, there have been fewer strong, healthy grunion runs in recent years.
“People ask me all the time, ‘How are the grunion doing these days?’ ” says Karen Martin, a biology professor at Pepperdine University and the region’s best-known expert on grunion. “I say, ‘It’s not their best year.’ ”
See How They Run
The story of “this quirky, kooky fish” is what draws people, says Mike Schaadt, a native southern Californian and the director of the beachfront Cabrillo Marine Aquarium in San Pedro. “It’s caught the attention of people in a romantic sense,” he said, “and also just how bizarre nature can be.”
Schaadt’s aquarium takes advantage of the unusual opportunity to unite observers with fish in the wild. Cabrillo Beach, just outside the aquarium’s door and in the shadow of the Port of Los Angeles, has long been known as a hot spot where grunion mingle.
Since 1951, the aquarium has been hosting “Meet the Grunion” on high-tide nights when the fish run. The entertainment starts inside, moves out to the beach, and endshopefullywith a real-life display of grunion spawning on the sand.
Last Saturday night, as the sun sank into the horizon, families, Cub Scouts, Girl Scouts, school groups, and budding scientists gathered in the aquarium’s auditorium to watch a short documentary of the fish’s life cycle.
Shot in 1964, the film is quaint by today’s high-def standards, but it captures spectators’ attention as they learn the details: Grunion ride the surf onto shore at the highest tides, under new and full moons and for three subsequent nights. Females shimmy back and forth to dig their tails into the sand and release a clutch of up to 3,000 eggs. Males, attracted by the movement, circle the females and release milt, which flows down their bodies and fertilizes the eggs.
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