Iconic Grunion: Annual Spawning

Gretchen Parker in Cabrillo Beach, California

for National Geographic

PUBLISHED JULY 6, 2014

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 (Leuresthes tennis) 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.' "

Source: Here