Who says Southern California doesn’t have seasons?
While some places ring in spring with cherry blossoms, Southern California’s spring is marked by the elusive natural wonder known as the .
Grunion are among the few fish to spawn completely out of water. They do it by the thousands, and they do it only in Southern California and Baja.
The grunion are running Friday night through Saturday, and this is likely to be the best and the last good opportunity of the year to observe the spectacle. On a good run, beachgoers can see thousands of the small silvery fish glittering in the moonlight as the waves come and go along the shoreline.
“It’s a pretty remarkable process,” said Melissa Studer, project director for Grunion.org, a Pepperdine University group of scientists, environmentalists and community members who monitor the grunion and educate the community about them. “They are pretty important culturally to us because this doesn’t happen anywhere else in the world, and it’s a very unique experience.”
The grunion spawn during the highest tide of the month from as early as March to as late as August, but April through June tends to be their most active period.
When they spawn, the females will wash ashore on the high tide, wriggle a few inches into the sand, tail first, leaving their heads exposed. They will each lay up to 3,000 eggs a few inches deep in the sand, and then the male fish will wrap around the female fish to fertilize the eggs.
Roughly 10 to 14 days later, the eggs will hatch, allowing the next generation to swim off with the tide. The grunion spawn at age 1 and have a life span of two to four years.
It is impossible to predict exactly where and when they will spawn, Studer said. Typically, the best day to see them is a few nights after the full or new moon, making Friday and Saturday good days to look for them this week, she added.
“We don’t know exactly where they are going to show up,” Studer said. “You have a two-hour window after high tide. You need to be patient and wait and look for the shorebirds—they always know where to find the grunion.”
The grunion play a big role in the ocean’s food chain, and observers will sometimes catch glimpses of small sharks and other predators during a run, she added.
The grunion do prefer a sandy beach with flat slopes and quiet conditions. They spawn on beaches from Baja up to Point Conception.
“Because of the way they spawn, the grunion are a very vulnerable species,” Studer said.
Through a nonprofit called BEACH ecology Coalition, Studer works with coastal communities to minimize the impact of human activity on the grunion. Specifically, some cities avoid conducting beach replenishment and grooming where it could impact the grunion eggs.
The group also educates the public about laws pertaining to the grunion run. People commonly capture the grunion and place them in buckets to use as bait, but certain laws and guidelines apply:
- Legally, you can use only your hands to capture the grunion.
- People over the age of 16 must have a license to catch grunion.
- Grunion cannot be captured in April or May.
- Be sure to wait until after the fish have spawned before capturing them.
- Only catch what you will use.
Violations can be reported to the California Department of Fish and Game at 1-888-DFG-CALTIP (1-888-334-2258).
Grunion.org asks for the public’s help in reporting grunion sightings for monitoring purposes.
The next grunion run is anticipated to be Saturday at 11:15 p.m. to 1:15 a.m., according to the Department of Fish and Game.