According to the California Department of Fish and Game, late March to early June is the peak time where the grunion have their orgy along California beaches. They crawl up the sand on nights with a full or new moon to spawn and do their slippery fish impression of that scene from From Here To Eternity.
Open season just, um, opened up for the tail end of this peak period (capturing grunion between April to May is prohibited)…which means this may be the last, best time to see a grunion (and catch and eat them) this year.
All you need is patience, luck, a flashlight, a fishing license (it is illegal
to catch them without one), and your hands (it is illegal to use any other implement or entrap them by digging holes).
Here's a description of the grunion love fest as written on the Department's site:
For four consecutive nights, beginning on the nights of
the full and new moons, spawning occurs after high tides and continues
for several hours. As waves break on the beach, grunion swim as far up
the slope as possible. The female arches her body and excavates the
semi-fluid sand with her tail to create a nest. She twists her body and
digs into the sand until she is half buried, with her head sticking up.
She then deposits her eggs in the nest. Males curve around the female
and release milt. The milt flows down the female's body until it reaches
and fertilizes the eggs. As many as eight males may fertilize the eggs
in a single nest. After spawning, the males immediately retreat toward
the water while the female twists free and returns with the next wave.
While spawning may only take 30 seconds, some fish remain stranded on
the beach for several minutes.
Though the Department of Fish and Game does not recommend specific beaches or guarantee sightings, they have predicted that tonight and tomorrow night (Friday, June 3rd from 10:35 p.m. – 12:35 a.m. and Saturday, June 4th, from 11:15 p.m. – 1:15 a.m.) are “probable two-hour interval(s) during which a
spawning run may occur.” The four night period actually began on Wednesday.
They add that: “The second hour is
usually better. The best runs normally occur on the
second and third nights of the four-night period.These times refer to the grunion runs at Cabrillo
Beach near the Los Angeles Harbor entrance.
The timing of the runs varies at different places along the coast.”
To see more info and more grunion harlequin romance stories, check their site.