The coastal running of the grunion

While most people reserve late weekend nights for their own fun, for those out there who want to see a different kind of show, this weekend is the last chance to see grunions getting frisky on Orange County beaches this year.

Yes, the seasonal phenomena known as the “Grunion Run” says goodbye to locals by early next week until March of next year. From Saturday to Tuesday, when the night skies will be almost totally black thanks to a new moon, thousands of grunions along the California coast are expected to give their last shot at breeding on the beach sand, and everyone gets to watch.

The grunion, a thin, silver fish that averages between four and six inches, breeds seasonally off California waters by riding high tides onto flat, smooth ocean sands and burying its eggs. The females dig themselves about six inches deep into the wet sand and release their eggs in a little nest. The males, some riding the same waves, work to wrap themselves around the busy females, release their fluid, or “milt,” on them, and let it drip down to the eggs to fertilize.

As many as eight males can fertilize eggs in a single nest, according to the state Department of Fish and Game. The whole egg-laying lasts about 30 seconds, but the grunions could be stranded on the beach for minutes until another large wave comes to carry them back to sea. Females can produce between 1,600 and 3,600 eggs during one spawn, state officials said.

If you’re on a beach during the grunion run, it’s unmistakable. A wave carries in hundreds and thousands of little shimmering slivers that shake, bounce and wiggle on the sand with every wave for hours. If you’re in Newport Beach, find the flattest, smoothest parts of the sand and wait.

To capture grunions to eat, you must be at least 16 years old and have a fishing license. The state prohibits people from digging holes or trenches to trap them. There is no limit to how many you can catch, “but take only what you can use — it is unlawful to waste fish,” the state’s website on grunions warns. The fish cannot be captured in April and May, but any other time, it is legal if you follow state laws.

While it is illegal to be on the beach after 10 p.m. in Newport Beach, police said officers use common sense when it comes to crowds and safety. So don’t cause a disturbance.

Grunion Run Times

Saturday: 11:06 p.m. to 1:06 a.m.

Sunday: 11:43 p.m. to 1:43 a.m.

Monday: 1:19 a.m. to 3:19 a.m.

Tuesday: 2:50 a.m. to 4:50 a.m.

Note: According to the Department of Fish and Game, the second hour is usually better to find grunions. The best runs normally occur in the second and third nights of a four-night period and they prefer long, flat beaches to steep profile beaches.