The Grunion are Back! What to Expect for 2025 California Grunion Runs
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Hojoman:
March 11, 2025
Guess who’s back? Or should we say, back again? California grunion are returning, so tell a friend! The California grunion spawning season begins in March and continues all the way through the end of August.
Grunion spawning events are also called grunion runs. Now, why would one want to know when the grunion are running? Well, these fish are unlike any other when it comes to their mating behavior, and it has become quite the spectacle across sandy Southern California shores.
First of all, what is a California grunion? The scientific name for this fish is Leuresthes tenuis and they belong to the family Atherinopsidae. They are a member of the New World silversides group, which includes jacksmelt and topsmelt. California grunion can be found from Tomales Bay, California to Bahia Magdalena, Baja California, Mexico; however, they are most abundant in the Southern California Bight where they inhabit nearshore coastal waters, tidepools, and bays. California grunion can grow up to 8 inches in total length and weigh up to about 1 ounce. They may live to be at least 4 years old.
two grunion on a sandy beach
Now to the good part. During full and new moons, late in the evening after the tides have hit their highest point, large numbers of male and female grunion will make their way onto the sandy shores. They do this by riding the breaking waves, swimming until their bodies are completely out of the water. The female grunion will then use her tail to dig into the sand and create a nest for her eggs. Females can lay between 1,600 and 3,600 eggs during one spawn, and this can happen up to six times per season! While this is happening, the male grunion will wrap himself around the female grunion to start releasing milt in hopes of fertilizing the female’s eggs. Once fertilization occurs, the eggs will incubate in the sand for about 10 days. Then when the high tides return, the waves will agitate the eggs to induce hatching, and a new life cycle begins.
Due to the unique mating ritual of grunion many locals come out to view this event, and catch grunion when the season is open. California grunion have been the subject of a recreational fishery for many years, which is why the state has protective fishing regulations in place for this fish.
To start, there are open and closed seasons for California grunion. In 2022, the state added the month of June to the April – May closed season. Grunion spawning peaks from April through June, so the closure is vital for uninterrupted spawning. However, the public is still welcome to come and observe grunion runs during the closed season. For the most rewarding viewing experience, it is best to keep your flashlights off and watch from a safe distance because grunion may not be disturbed or handled during this time.
Be aware that this year, the fishing season closes on March 31 at midnight, right in the middle of a grunion run! You can still watch the run in the wee hours of April 1, but grunion may not be disturbed or handled after midnight.
When the season opens again on July 1, grunion may only be taken by hand, without the use of any equipment such as nets, colanders, etc. and holes cannot be dug to entrap them. Any angler that is 16 years old or older must have a recreational fishing license (an Ocean Enhancement Validation is also required to fish in ocean waters south of Point Arguello (Santa Barbara County); although the validation is not required when fishing with a one- or two-day sport fishing license). As part of the 2022 regulation change, there is now a daily bag and possession limit of 30 grunion per person. These regulations were put in place to protect and conserve declining grunion populations, so that we may keep enjoying these runs into the future.
If you are interested in finding out more about these runs, have been anxiously awaiting the latest news on grunion, or need a reminder of the fishing regulations, visit the California Department of Fish and Wildlife’s 2025 California Grunion Facts and Expected Runs web page ( https://wildlife.ca.gov/Fishing/Ocean/Grunion ). Happy grunion hunting!