The regular season wraps up against the Cubs at Wrigley Field with a three-game. As they come up onto the shore the female Grunion will lay their eggs as high up on the beach as they can. Grunion Run Schedule San Diego runs occur about 5 minutes earlier and Santa Barbara runs occur about 25 minutes later than the times provided here.
Typically the third and fourth nights tend to be a bit better. These small, silvery fish are one of just two fish species that beach themselves to lay their eggs. The other beach spawner is their sister species, the gulf grunion L. As waves wash up the sandy shore, grunion surf onto the beach. Unlike salmon, grunion do not die after spawning.
They can spend up to a couple of minutes flopping on the beach before returning with the waves, and can return to spawn on the beaches many times during the season. Unfortunately, the past decade has seen a decline in the grunion population. Later this year, the Fish and Game Commission will consider proposed new regulations designed to help the grunion population recover. If you fish for grunion, CDFW is seeking your input to better inform our understanding of the fishery.
Grunion are somewhat hearty but like other fish, are susceptible to pollution and human activities. Grunion Greeters are trained volunteers who stand on the beach during the first few months of the run season, observing the fish activities and recording them for NOAA records and the Grunion Greeter science project.
March 13 Saturday p. March 14 Sunday 11 p. March 15 Monday p. March 16 Tuesday p. March 28 Sunday p. March 29 Monday p. March 30 Tuesday p. March 31 Wednesday Midnight-2 a. June 10 Thursday p. June 11 Friday p. June 12 Saturday p. June 13 Sunday p. June 24 Thursday p. June 25 Friday p. Additional frequently asked questions , information on volunteer programs, and other information may be found at www. Along Southern California's sandy beaches, from March through September, one of the most remarkable life cycles in the sea is completed: the California grunion come ashore to spawn.
The grunion has been known to many Southern Californians for more than years, but there are still those who are skeptical of its existence. To be invited out in the middle of the night to go and watch fish does sound a little ridiculous, but in reality this is the only way to observe this natural phenomenon. California grunion are small, silvery fish found only along the coast of Southern California and northern Baja California. Most people would be unaware of their existence were it not for the unique spawning behavior of these fish.
Unlike other fish, grunion come completely out of the water to lay their eggs in the wet sand of the beach. As if this behavior were not strange enough, grunion make these excursions only on particular nights, and with such regularity that the time of their arrival on the beach can be predicted a year in advance. This phenomenon can be seen on many beaches in Southern California.
Shortly after high tide, on certain nights, sections of these beaches are sometimes covered with thousands of grunion depositing their eggs in the sand. Grunion watching has become a popular sport in Southern California. Since these fish leave the water to deposit their eggs, they may be observed on shore while they are briefly stranded. The common sight of thousands of people lining the more popular beaches in Southern California in anticipation of a grunion run attests to its ever-growing popularity.
Often there are more people than fish, so to protect the species, it is important to let them spawn without disturbance. All that is needed to observe grunion is an adventurous spirit and the patience to find a promising beach and then wait for a run to begin.
Grunion are small slender fish with bluish green backs, silvery sides and bellies. Their average length is between 5 and 6 inches. Early Spanish settlers called this fish grunion , which means grunter. This term has been anglicized into grunion. Grunion are known to make a faint squeaking noise while spawning. The scientific name for the California grunion is Leuresthes tenuis , and this fish belongs to the family Atherinidae, commonly known as silversides.
Other more abundant atherinids found in California are the topsmelt, Atherinops affinis , and jacksmelt, Atherinopsis californiensis. Silversides differ from true smelts, family Osmeridae, in that they lack the trout-like adipose fin.
However, there are small populations both north and south of these points. Occasionally grunion may appear in fair numbers as far north as Morro Bay, California, and spawning has been reported as far north as Monterey Bay, California.
Recently, grunion have been observed spawning inside San Francisco Bay. A close relative of the California grunion is the gulf grunion, Leuresthes sardina , which is found in the Gulf of California. This species spawns both day and night, while the California grunion spawns only at night.
The spawning season extends from late February or early March to August or early September, varying slightly in length from year to year. Actual spawning runs are restricted to relatively few hours during this period. Grunion spawn only on 3 or 4 nights after the highest tide associated with each full or new moon and then only for a 1 to 3 hour period each night following high tide.
Spawning runs typically begin with single fish usually males swimming in with a wave and occasionally stranding themselves on the beach. Gradually, more and more fish come in with the waves and by swimming against the outflowing wave strand themselves until the beach is covered by a blanket of grunion. Spawning normally starts about 20 minutes after the first fish appear on the beach.
Typically a run lasts 1 to 3 hours, but the number of fish on the beach at any given moment can vary from none, to thousands. Peak activity is reached about an hour after the start of the run and lasts from 30 to 60 minutes. Finally, when the tide has dropped a foot or more, the run slackens and then stops as suddenly as it started. No more fish will be seen that night, and they will not appear again until the next night or the next series of runs.
Observing grunion can be much more interesting than catching them. Females ride a far reaching wave onto the beach accompanied by as many as eight males. If no males are present,a female will return to the ocean with the outflowing wave. In the presence of males, she swims as far up on the beach as possible and literally drills herself into the sand as the wave recedes. This is accomplished by arching her body with the head up, and at the same time vigorously wriggling her tail back and forth.
As her tail sinks into the semifluid sand, she twists her body and drills herself downward until she is buried up to the pectoral fins. Occasionally she may bury herself completely.
The male or males curves around her as he lies on top of the sand, with his vent close to or touching her body. The female continues to twist, emitting her eggs 2 or 3 inches beneath the surface of the sand. Males discharge their milt onto the sand near the female and then immediately start to wriggle towards the water. The milt flows down the body of the female and fertilizes the eggs. The female then frees herself from the sand with a violent jerking motion and returns to the sea with the next wave to reach her.
This entire process takes about 30 seconds, but individual fish may remain on the beach for several minutes. Larger females are capable of producing up to 3, eggs every 2 weeks. As the mature eggs are deposited in the sand, another group of eggs are developing that will be spawned during the next series of runs.
This cycle continues throughout the season. During the early part of the season only older fish spawn, but as the season progresses fish hatched the previous year come into spawning condition and join the runs. Fish of all ages will spawn by April and May.
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