Millions of grunions, hotdog-shaped fish measuring up to 5 inches in length, have descended upon the Southern California and Northern Baja California coasts for their annual mating ritual. Unlike most fish, grunions have a distinctive reproductive behavior known as the “grunion run,” which occurs from February to September, with a peak from April to June. During this period, the fish come ashore during full or new moons, when high tides facilitate their water sports. The females swim close to the beach, jump ashore, and use their tails to burrow holes in the sand, where they deposit around 3,000 eggs. The males then fertilize the eggs, and both sexes remain buried until the next high tide, which carries them back to sea. The hatched baby grunions eventually emerge from the sand. This captivating spectacle has become a local legend and has attracted crowds of people, including citizen scientists known as “grunion greeters,” who have been observing the fish orgies since 2002. These volunteer voyeurs monitor the ritual at over 50 California beaches and report their findings to biologist Karen Martin, who has studied grunions for decades. Martin emphasizes the importance of these citizen scientists in studying the fish, as they are nearly impossible to count at sea and avoid traditional stock assessment methods. Studying grunions is crucial due to concerns about their declining population and the threats posed by environmental factors such as beach erosion, beach grooming machines, climate change, birds, and other predators. Despite these challenges, the grunions’ annual mating ritual remains a captivating natural phenomenon that showcases the wonders of the marine world.
Millions of Grunions Converge on California Beaches for Annual Mating Ritual
