For kids: The grunion are running

A cooperative effort between two aquariums allows people in France to watch in real time as grunion spawn on southern California beaches.

"Water, water, water," yells Mike Schaadt, director of Cabrillo Marine Aquarium in Los Angeles. He scrambles backward in the sand, away from an incoming wave on Cabrillo Beach. "I'll try not to drop you in the water, Stéphane," he says to a man's image on a laptop he's holding by a strap in his left hand. In his right hand, Mr. Schaadt has a wooden pole with an antenna attached to it.

Next to him, Ed Mastro, exhibits director of the aquarium, aims a small video camera at hundreds of silver fish wriggling on the beach, where they have come to deposit their eggs. The fish are small, about five to six inches long, and their slender bodies shimmer in the moonlight as they ride the surf onto the sand.

It's a grunion run, and almost 300 people have gathered on Cabrillo Beach in San Pedro, Calif., to watch this spawning ritual late on a Wednesday night. Stéphane Henard, the man on the laptop, is watching, too, but from a beach thousands of miles away in Boulogne, France. Mr. Henard, director of NAUSICAÄ, the French National Sea Experience Centre, is watching a live webcast of the grunion on his computer.

The gear Messrs Schaadt and Mastro are juggling above the waves is sending the live images to Mr. Henard using Skype, an Internet calling service.

It's 11:30 p.m. in San Pedro, and families are bundled up in jackets, sweat shirts, and blankets, but in Boulogne it's 8:30 in the morning, and Mr. Henard is wearing a short-sleeved shirt under sunny skies.

Fish out of water

Grunion are ordinary-looking fish that live off the coast of southern California and northern Baja California (a state in Mexico). They swim in the sea and use their gills to breathe just as other fish do. So why do crowds of people brave dark, chilly nights to see them? Because unlike other fish, grunion come completely out of water and onto land to reproduce.

Between March and August, the grunion run ashore a few nights after the new and full moons, when high tides are higher than normal. Usually between 10:00 p.m. and 1:00 a.m., high tide washes the fish onto several California beaches. There, females dig their tails into the sand while males curl around them to fertilize the eggs the female fish are laying. When the process is finished – in as little as 30 seconds – they all catch the next wave back into the ocean.

The eggs remain buried in the sand and incubate for 10 to 14 days until the next new- or full-moon high tide comes in and washes them out to sea. The churning motion of the waves bursts the protective membrane of the eggs and the tiny fish are hatched.

How grunion got to France

Mr. Henard first learned about grunion almost 12 years ago at an International Aquarium Congress meeting in Tokyo, Japan's capital city. Dr. Susanne Lawrenz-Miller, the director of Cabrillo Aquarium at the time, ended her presentation by hatching grunion eggs in a glass jar for the audience. Mr. Henard was impressed and hoped to share the fish's compelling life cycle with visitors at his aquarium. Now that hope is reality.

Tonight is a test to see how the beach-to-beach webcast works. After that, the grunion-run live webcasts are set to be part of NAUSICAÄ's exhibit on direct communication with the sea.

It took some trial and error to set up the webcast. In the end, Mr. Mastro opted to use a standard DSL connection in the aquarium's library with a high-output antenna aimed toward the nearby beach.

Mr. Henard's image is projected from the laptop onto a makeshift screen on a lifeguard tower so everyone on the beach can see him. He and Mr. Schaadt toss questions back at forth to each other.

"How is the new exhibit?" Mr. Schaadt asks.

"Ah, it's a big success," Mr. Henard replies. "These last two weeks we've had twice the usual attendance."

Hatching the eggs far from the ocean

Cabrillo Aquarium sent grunion eggs packed in sand to NAUSICAÄ so Mr. Henard could hatch the eggs from glass jars in front of visitors. "So far, 20,000 people in France have seen the demonstration," he says.

Because grunion are a foreign species in France, the hatched fish are kept in a controlled tank and will never be introduced to European waters.

Back in California, Cabrillo Aquarium attracts more than 3,000 people to its grunion-run programs on weekend nights during summer, which include a video, hatching eggs in jars, and trekking out to watch the grunion come ashore.

By 12:30 a.m., the grunion have completed their spawning and people on the beach start to head home. "That was cool!" a boy in the crowd says, looking up at his dad. "Can we come again?"

Mr. Henard hopes that kind of excitement catches on with children in France.