Don’t Miss the Grunion Run on Oceanside Beaches!

During the spring and summer season, Oceanside’s beaches offer a truly unique chance to witness one of nature’s most fascinating phenomenons! Known as the Grunion Run, every year hundreds to sometimes thousands of small 5-6″ silvery fish ride the waves onto the shore, purposefully beaching themselves as part of their remarkable spawning behavior. This momentous event occurs March through August for three to four days at a time, following a full or new moon, immediately after the tide has reached its highest point.

The proceedings usually begin with a few brave males stranding themselves onto the beach first, followed by more and more fish. Females then ride the larger waves onto shore and swim as far up on the beach as they can, building a small “nest” and burying themselves in the process. There in the sand the females release their eggs a few inches below the sand surface and the surrounding males fertilize the eggs. After the process is complete, the beached fish shake and heave themselves towards the waves to get swept back into the ocean.

Grunion Run Facts

  • Grunion can begin spawning once they reach maturity at 1 year old.
  • The normal grunion lifespan is 2 or 3 years long.
  • Female grunions can lay anywhere from around 2,000 to close to 4,000 eggs!
  • Grunion eggs take about a week-and-a-half to hatch.
  • Baby grunion will hatch 2 or 3 minutes after the eggs are washed out to sea during the return of high tide.
  • Grunions travel in big schools, effectively covering the beach with fish during peak times of the Grunion Run.

Grunion Run Schedule

The schedule for the Grunion Runs is an estimation for the nights and hours when the grunions will most likely arrive. The Grunion Run times for Oceanside beaches do vary March – August so be sure to check the Visit Oceanside Event Calendar and the California Fish & Wildlife Expected Grunion Runs often for specific days and times you are most likely to witness the spectacle.

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An Experience Worth Seeing

The grunion’s mating ritual is incredibly unique compared to other fish (literally fish out of water!), and is a natural spectacle specific to our Southern California beaches! Plus, during the months of March, June, July and August you can also participate in grunion hunting. To catch grunion a California Sport Fishing License is required for those that are 16 and older. Leave the poles at home though, these fish have to be caught with your hands (hole traps are prohibited). To learn more about grunion hunting as well as open season dates visit Grunion Hunting FAQ’s.

More: Fishing with the Family in Oceanside

So take a nap, bring your flashlight, grab a jacket and get ready to witness something special in Oceanside!

Published: March 11, 2019

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